66_03 results of therapy

Results of Therapy

When therapeutic results in invasive carcinoma of the cervix are evaluated, a direct comparison of surgically treated or irradiated patients is fraught with many uncertainties, including patient selection, reporting of surgical cases using staging determined by laparotomy findings, and different treatment techniques (670).

The impact of patient selection in results of surgical series was illustrated by Whitney and Stehman (654), who evaluated the frequency with which intended radical hysterectomy for cervical cancer is abandoned and the outcomes for those selected patients. In 1,127 patients with stage IB carcinoma of the cervix entered on GOG Protocol 49, 98 women (8.7%) were found at surgery to have extrauterine disease, and the proposed radical operation was abandoned. Subgroups of patients with extrapelvic disease (30) and pelvic extension (26), including grossly positive pelvis nodes (12), other pelvic implants (8), and gross serosal extension (2), were identified. Sixty-three (93%) patients subsequently underwent pelvic radiation therapy and brachytherapy. Para-aortic fields were added for eight patients who were found to have positive para-aortic nodes. The disease-free survival was shorter for patients whose radical procedure was abandoned than for those patients who underwent radical hysterectomy.

Stage IA

In 47 patients with microinvasive carcinoma treated at Washington University, 20 with intracavitary therapy only and 27 patients with combined external irradiation and intracavitary brachytherapy, only one patient had a pelvic recurrence and distant metastases 10 years later; the 5-year disease-free survival rate was 96% (201).

Webb et al. (644) analyzed lymph node status and survival rates of women with microinvasive cervical adenocarcinoma (FIGO stages IA1 and IA2) from the SEER database between 1988 and 1997. Among reported cases, 131 had stage IA1 and 170 had IA2 disease. Simple hysterectomy was done in 54 women with IA1 and 64 with IA2 disease and radical hysterectomy in 50 and 83 women, respectively. Only 1/140 women who had lymphadenectomy had a single positive lymph node. There were four tumor-related deaths (one with IA1 and three with IA2 disease). The survival rate was 98.7%.

Stages IB and IIA

The important contribution of external-beam irradiation to improve pelvic tumor control in larger lesions has been documented. Hamberger et al. (226), in 151 patients with stage IA or IB lesions <1 cm in diameter treated with intracavitary therapy

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alone to high doses (8,640, 9,340, and 13,680 mgh), noted no failures in 41 patients with stage IA disease, and only 4/93 patients (4%) with stage IB, small-volume disease. However, 3/17 patients (18%) with more extensive stage IB lesions, treated with intracavitary therapy only, had regional failures. Only 3/151 patients (0.2%) had grade 3 complications.

Volterrani and Lombardi (639) reported 5-year survival of 82.6% in 23 patients with occult stage IB carcinoma of the cervix treated with intracavitary 226Ra only (7,500 mgh) in contrast to only 64.8% in larger stage IB tumors and 50% in stage II. Unfortunately, the authors did not report the exact location of the failures. It is obvious that intracavitary therapy alone is grossly inadequate to irradiate larger primary tumors, including stage IB1.

With EBRT and BT, the usual 5-year survival rate for stage IB is 86% to 92%, and for stage IIA, approximately 75%. The overall pelvic failure rate in stage IB is approximately 5% to 8%, and in stage IIA, 15% to 20% (in half of the patients combined with distant metastases). Either surgery or adequate irradiation is equally effective in the treatment of stage IB and IIA carcinoma of the cervix; numerous noncontrolled studies support the merits of either modality with no significant difference in survival or pelvic tumor control (Tables 66.16 and Fig. 66.23). Saibishkumar et al. (541) published a retrospective review of 1,069 patients with cervical cancer treated with EBRT and BT to median point A dose of 81 Gy; 5-year overall pelvic tumor control was 63.9%, DFS 49.4%, and overall survival 51.8%. Late toxicity was observed in 1% to 2% of the patients.

Randomized Studies

A few randomized studies of radical operation and irradiation have been published; outcome with the two modalities is comparable. Newton (441) and Roddick and Greenlaw (516) reported, in prospectively randomized studies, equivalent survival and pelvic recurrence rates in patients with stage IB and IIA carcinoma of the uterine cervix treated with a radical hysterectomy or irradiation alone.

Landoni et al. (352) published results of a prospective, randomized trial of radiation therapy versus surgery; 469 women with stage IB and IIA cervical carcinoma were referred for treatment and 343 were randomized (172 to surgery and 171 to radiation therapy). Postoperative irradiation was delivered after surgery for women with surgical stage pT2b or greater, <3 mm of safe cervical stroma, and cut-through margins or positive pelvic nodes. Scheduled treatment was delivered to 169 and 158 women, respectively; 62/114 women with cervical diameters of <4 cm and 46/55 with >4 cm received radiation

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therapy. After a median follow-up of 87 months (range, 57 to 120 months), 5-year overall and disease-free survival rates were nearly identical in the surgery and radiation therapy groups (83% and 74%, respectively); recurrent disease developed in 86 women: 42 (25%) in the surgery group and 44 (26%) in the radiation therapy group (Fig. 66.24). Forty-eight patients (28%) in the surgery group had severe morbidity compared with 19 (12%) in the radiation therapy group (p = 0.0004; Table 66.17). The combination of surgery and radiation therapy had the worst morbidity, especially urologic complications.

Nonrandomized Studies

Kielbinska et al. (313), in a long-term study of 792 women treated with irradiation and 789 women treated with hysterectomy and irradiation for stage I cervical carcinoma, found no difference in survival, general health, incidence of recurrent carcinoma, or appearance of second primary malignancies.

Piver et al. (489) treated 103 women with stage IB cervical carcinoma with either radical hysterectomy and pelvic lymphadenectomy (if tumor <3 cm in greatest diameter) or

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irradiation (tumor >3 cm or medically inoperable). The 5-year disease-free survival rate was 92.3% for the surgical group and 91.1% for the radiation therapy group. Equivalent overall 5-year survival rates were noted.

In stage IB and IIA disease after a hysterectomy and lymphadenectomy (even combined with irradiation), patients with metastatic lymph nodes have survival rates that are approximately 50% of those of patients with negative nodes (284).

Einhorn et al. (147), in a nonrandomized study, observed a 100% 5-year survival rate in 49 patients with stage IB disease receiving combined therapy in comparison with 81% in 64 patients treated with irradiation alone. No difference was observed in 25 patients with stage IIA tumor treated with combined therapy and 40 patients treated with irradiation alone (5-year survival rate, 75%).

Perez et al. (471) reported on a prospectively randomized study of 118 patients with stage IB or IIA carcinoma of the uterine cervix in which patients were treated with RT alone or irradiation and surgery (20 Gy to the whole pelvis, one intracavitary insertion for 5,000 to 6,000 mgh, followed by a radical hysterectomy with pelvic lymphadenectomy 2 to 6 weeks later). In stage IB, the 5-year tumor-free survival was 80% and 82% (p = 0.23), respectively, and in stage IIA, 56% and 79%, respectively (p = 0.13). The incidence of grade 2 or 3 complications radiation alone was 13.8% and with preoperative irradiation and surgery 11%.

Subsequently, Perez et al. (472) described results in 415 patients with stage IB or limited stage IIB treated with preoperative or postoperative irradiation and surgery. The 10-year cause-specific survival rate for patients with stage IB nonbulky tumors treated with irradiation alone or irradiation combined with surgery was 84% with either modality. With bulky tumors (>5 cm), the 10-year rates were 61% and 68%, respectively (p = 0.5). For patients with stage IIA nonbulky tumors, the 10-year cause-specific survival rates were 66% and 71%, respectively, and with bulky tumors, 69% and 44%, respectively (p = 0.05). In patients with stage IIB nonbulky tumors treated with irradiation alone or combined with surgery, the 10-year cause-specific survival rates were 72% and 65%, respectively.

Stages IB and IIA (Bulky)

Mendenhall et al. (408) compared 75 patients in each group treated with irradiation alone or combined with surgery for bulky tumors and reported local tumor control of 74% and 76%, and absolute 54% and 52%. The authors currently reserve combining irradiation with an extrafascial hysterectomy for patients who have <25% tumor regression at the time of the first intracavitary application, who are medically operable, and in whom it is thought adequate surgical margins may be obtained.

Thoms et al. (611) reported on 363 patients with bulky endocervical carcinoma treated with curative intent (246 with irradiation alone and 117 with irradiation and surgery); 10-year survival was 45% and 64%, respectively. In a subset of 48 patients with similar tumors treated with irradiation alone and 45 with irradiation and surgery, the 10-year survival rates were comparable, and the pelvic tumor control rates were 90% and 87%, respectively.

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Eifel et al. (144) evaluated 1,526 patients, of whom 371 had tumors 6 cm or greater. There were biases in treatment selection, but a statistically significantly higher 10-year survival rate was noted in patients treated with irradiation and surgery (64% vs. 45%). Tumor diameter was highly significant as a prognostic factor, and they concluded that only patients with lesions >8 cm in diameter benefited from adjuvant hysterectomy. In the same study, 98 patients with stage IB and IIB bulky endocervical carcinomas (≥6 cm in diameter) were treated with RT alone. Twenty-four patients received <6,000 mgh of intracavitary treatment, and 73 received higher doses. Despite having somewhat more favorably treated tumors, patients who received <6,000 mgh had a higher rate of pelvic recurrence at 5 years (33%) than those who received higher doses (16%; p = 0.03). Actuarial 5-year survival rates were 44% and 60% for low- and high-dose groups, respectively (p = 0.14).

Kim et al. (318) assessed the prognostic factors for pelvic tumor control in 40 patients with FIGO stage IB or IIA carcinoma, and 25 patients with stage IIB carcinoma classified as barrel-shaped (i.e., at least 5 cm in diameter) treated with curative intent. Seventy-two percent were treated with RT alone and 28% with RT and extrafascial hysterectomy. The extent of tumor regression after external-beam radiation therapy correlated with the likelihood of local tumor control (p = 0.02). For patients treated with radiation therapy alone, increased brachytherapy dose was associated with better local tumor control. The 10-year overall and cause-specific survival rates were 53% and 68%, respectively, and did not differ significantly between treatment groups.
Paley et al. (458) reported on 57 patients with barrel-shaped (mean diameter, 5 to 9 cm) cervical carcinoma treated with preoperative EBRT and BT (mean dose to point A, 79.6 Gy) followed by extrafascial hysterectomy 6 to 8 weeks later. Residual disease was present in 35 (61%) of the hysterectomy specimens; tumor sterilization correlated significantly with the mean dose to point A (p = 0.016). Ninety-five percent of the patients with negative specimens remained clinically free of disease at their last follow-up versus 31% of those with residual disease (p < 0.001).
The GOG and RTOG conducted a randomized phase III clinical trial in which 282 patients with carcinoma of the cervix measuring 4 cm or greater (exophytic or barrel-shaped) were treated with either external-beam and intracavitary irradiation or a slightly lower dose of intracavitary irradiation and the same pelvic EBRT followed by an extrafascial hysterectomy (311). The survival rates were 61.4% for irradiation alone and 64.4% for the combined irradiation and surgery group. The incidence of recurrences was 43.3% in the irradiation group compared to 34.5% with combined therapy (p = 0.081). The incidence of local recurrences was 25.8% 14.4%, respectively. The incidence of grade 3 and 4 sequelae of therapy was 10.5% and 9.8%, respectively. Thus, the addition of hysterectomy to standard irradiation did not significantly affect survival, although there was a small reduction in the local recurrence rate.

When combined therapy is used, the dose of irradiation delivered to the lymph nodes, the time of the operation, and the pathologic examination of the specimens are critical in

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determining the presence of postirradiation residual tumor (Table 66.18).

Perez et al. (470) noted that in patients with primary carcinoma of the uterine cervix who had endometrial stromal invasion or tumor only in the curettings, the addition of a hysterectomy did not improve the survival rate because most of the patients failed at distant sites.

Stages IIB, III, and IVA

Most patients with stage IIB tumors are treated with irradiation alone, and the 5-year survival rate is 60% to 65%. The pelvic failure rate ranges from 18% to 39%. In an analysis of the Patterns of Care Study in 157 patients who had stage IIB disease, Coia et al. (90) reported a better 4-year survival rate (67% and 54%) and in-field tumor control rate (78% and 68%) in patients with unilateral versus bilateral parametrial involvement, respectively.

Similarly, in a review of 1,178 patients with stage IIB disease treated at Washington University, the 5-year survival rates were 70% with medial parametrial and 58% with lateral parametrial involvement (p = 0.004) (533).

Kim et al. (320), in patients with stage IIB, found a correlation of point A dose and incidence of pelvic failures (Fig. 66.25). Before 1965, a pelvic lymphadenectomy was carried out at M.D. Anderson Hospital after a full course of radiation therapy, but this procedure did not improve survival over irradiation alone and the complication rate was somewhat higher (161).

In stage IIIB carcinoma, the 5-year survival rates range from 25% to 48%, and pelvic failure rates range from 38% to 50% (161,417).

Hanks et al. (228), reporting on the Patterns of Care Study, noted a 28% probability of 5-year survival in patients with stage III carcinoma of the cervix treated in a large number of facilities in the United States versus 60% survival in selected large centers (extended survey).

Later, Komaki et al. (334) reported a significant increase in local pelvic tumor control (69%) in patients with stage III carcinoma of the cervix treated in 1983, compared with 37% and 49% in earlier periods (p = 0.03). The 5-year survival rate increased from 25% to 47% (p = 0.02). The improvement in pelvic tumor control may be associated with higher external beam doses, but more likely is related to the substantial increase in the percentage of patients receiving brachytherapy (96%) and more careful dosimetry and dose calculations for intracavitary therapy. They noted a decrease in major complications from 15% in the 1973 and 13% in the 1978 Patterns of Care Surveys to 7% in 1983.

Montana et al. (418) reported that calculation of doses to the bladder and rectum were performed in 80% and 76% of patients, respectively, in the 1983 survey, which may also have resulted in decreased toxicity.

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Arthur et al. (23), in 89 patients with stage IIIB carcinoma of the cervix treated with external irradiation and brachytherapy, observed a locoregional tumor control rate of 22.5% and a disease-free survival rate of 15% in 16 patients treated with 78 Gy or lower doses to point A, in comparison with 53% and 47%, respectively, in 24 patients receiving higher doses.

Horiot et al. (259) reported the results of a French cooperative study of 1,383 patients with invasive carcinoma of the uterus treated with irradiation alone following the M.D. Anderson Hospital treatment guidelines. Survival and locoregional tumor control were similar in both groups, except in stage III, in which the pelvic and central failure rates were lower in the French patients, probably because of different tumor volumes or socioeconomic factors. Major urinary complications were noted in 2% of the patients and grade 3 bowel complications in 3% of the patients with stage I and IIA disease, and bowel complications in 7% of patients with IIB and III disease.

Barillot et al. (28) updated the results in 642 patients; the analysis was divided into three periods: 1970 to 1978 (use of standard prescriptions), 1979 to 1984 (implementation of individual adjustments), and 1985 to 1994 (systematic individual adjustments). There was a significant reduction of the external radiation dose (above 40 Gy in 47% of patients before 1979 vs. 36% after 1984), use of parametrial boost (55% vs. 39%), of use of vaginal cylinder (28% vs. 11.5%), and of combined intracavitary and external irradiation volume (842 cm3 vs. 503 cm3 on average). The 5-year actuarial toxicity rates were grade 2, 23.5%; grade 3, 10%; and grade 4, 3%. The three main predictive factors for rectal and bladder sequelae were increased external radiation dose, higher dose rate at reference points, and whole-vagina brachytherapy. The disease-free survival rates observed with irradiation alone at Washington University Medical Center are shown in Figure 66.26.

Marcial et al. (399) described results of a randomized trial in 301 patients with stage IIB, III, and IVA carcinoma of the uterine cervix treated with split-course irradiation (10 fractions of 2.5 Gy, five weekly doses up to 25 Gy, followed by a rest period of 2 weeks, and an additional 25 Gy delivered in the same manner) or continuous irradiation (30 fractions of 1.7 Gy daily, five times per week, total dose 51 Gy) combined with LDR brachytherapy for 30 Gy to point A. There was no significant difference in tumor control, acute or late complications, or survival in the two groups.

In patients with stage IVA disease, the 5-year survival rates range from 18% (333) to 34%, and pelvic failures from 60% to 80% after definitive irradiation. Million et al. (412) reported 18/53 patients (34%) with bladder involvement surviving without disease after definitive irradiation, results comparable with those obtained with exenteration.

Upadhyay et al. (625) noted 43% local tumor control and 18% 5-year survival rates in 44 patients with stage IVA carcinoma of the cervix treated with definitive radiation therapy.

Kramer et al. (337) reported on 48 patients with stage IVA carcinoma of the cervix treated with definitive RT. Patients with minimal parametrial involvement had a 5-year survival rate of 46% compared with only 5% for those with extensive parametrial tumor. The major complication rate was 22%, consisting mostly of vesicovaginal fistula in five patients.

Crozier et al. (102) described equivalent 5-year survival rates after salvage pelvic exenteration (37% in 35 patients with adenocarcinoma and 39% in 70 patients with squamous-cell carcinoma). In the adenocarcinoma group, 14/22 patients, and in the squamous cell-carcinoma group, 14/30 patients had distant metastases after pelvic exenteration.

Treatment of Elderly Patients

Oguchi et al. (451) reported on 23 patients 90 years of age or older treated with cervix carcinoma. Definitive radiation therapy was completed in 13 of the patients, and local tumor control at 6 months was attained in nine patients. Palliative RT was completed in 7/11, and palliation was observed in nine patients (81%). Seven patients were alive for 15 to 67 months. Fourteen patients died because of intercurrent disease or senility associated with active cancer, and two because of senility without evidence of cancer. The 2-year overall and relapse-free survival rates were 30% and 21%, respectively.

Multivariate Analysis

Fyles et al. (170), in 965 patients with invasive carcinoma of the cervix, identified FIGO stage as the most significant prognostic factor, followed by dose of irradiation to point A and overall time of radiation therapy. The 10-year survival rate was 62% in 743 patients receiving doses to point A of 85 Gy or higher, in contrast to 53% for 222 patients receiving lower doses.

Patients with higher hemoglobin levels not receiving a transfusion (595) had a 10-year survival rate of 60% in contrast to 42% in 353 patients who were given transfusions for lower hemoglobin levels.

Chatani et al. (75), in 216 patients with stage IIB-III cervical carcinoma treated with a combination of external-beam and HDR brachytherapy, noted that overall treatment time was the most highly significant factor for local tumor control in multivariate analysis (p = 0.0005). Concerning relapse-free survival, stage classification (p = 0.0001), overall treatment time (p = 0.0035), and hemoglobin level (p = 0.0174) were the three

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most important prognostic factors; there was no relationship between treatment time and late complications.

Kapp et al. (299), in a study of 181 patients with FIGO stages IB to IV carcinoma of the cervix, documented that prognostic factors for patients treated with HDR are similar to those in previous series with LDR brachytherapy. In multivariate analysis, tumor size was the most powerful for pelvic tumor control and incidence of distant metastasis.

Interstitial Implants

Interstitial brachytherapy, discussed in detail in Chapter 20, has been used in the treatment of patients with cervical cancer (591).

Because of the inability to insert an intracavitary tandem interstitial needle, implants were used at Washington University in 30 patients with stage IIB and in 37 with stage III carcinoma to deliver interstitial irradiation in the parametrium to supplement the dose delivered by external-beam and intracavitary brachytherapy. Despite the fact that the patients treated with interstitial implant were in a high-risk group, local tumor control was comparable with that of patients treated with standard techniques (474).

Pierquin et al. (484) described locoregional recurrences in 6% of 53 patients with T1, 11% in 47 with T2, and 42% of 19 patients with T3 primary tumors of the uterine cervix treated with a combination of external-beam irradiation and the Creteil method for interstitial implantation of 192Ir sources in a plastic cervical-vaginal moulage and a uterine tandem.

Prempree (502) reported a 96% local tumor control rate and 61% 5-year disease-free survival rate in 23 patients with stage IIIB carcinoma of the cervix treated with a combination of external irradiation and intracavitary and interstitial implants to the parametrium. Overall, major complications were noted in 8% of the patients.

Martinez et al. (402), using the Martinez Universal Perineal Interstitial (MUPIT) applicator, treated 37 patients with advanced or recurrent carcinoma of the cervix and 26 with vaginal-urethral tumors. Doses of approximately 35 Gy were given, in addition to external irradiation (36 Gy to the whole pelvis and 14 Gy to the pelvic sidewall). They reported six local failures in the patients with cervical lesions and five in the group with vaginal-urethral tumors. The overall complication rate was 5.1%.

Nag et al. (430) reported on 31 patients with carcinoma of the cervix and eight with carcinoma of the vagina treated with external-beam radiation therapy and fluoroscopically guided interstitial brachytherapy. With a median follow-up of 36 months, 16 patients (51%) with cervical and five patients (62.5%) with vaginal carcinomas had local tumor control. The 5-year actuarial survival rates were 34% and 38% for cervical and vaginal cancers, respectively. Only one patient experienced grade 3 complications (2.5%).

Recio et al. (508) used laparoscopy at the time of interstitial brachytherapy in six patients with FIGO stages IIB to IVA cervical carcinoma, after completion of whole pelvis radiation; a total of 98 needles were inserted to deliver a median interstitial brachytherapy dose of 20 Gy. Eleven perforations in the pelvic peritoneum or bladder were identified during surgery in five of the six patients, leading to immediate repositioning of needles. No acute or short-term morbidity related to the procedure was noted.

Californium-252 or Neutrons

Maruyama and Muir (404) reported on 41 patients with stage IB cervix cancer treated with 40 to 50 Gy to the whole pelvis followed by a 5- to 15-Gy boost to the lateral pelvic wall and a single 252Cf-neutron brachytherapy insertion in approximately 8 hours. Nearly total tumor clearance was achieved in over 90% of the patients; tumor regression was more rapid in the 252Cf group than in similar patients treated with 137Cs and the same external-beam irradiation dose.

Maor et al. (398) published results in 156 patients with locally advanced cervical carcinoma treated at five institutions and randomized to receive external photons only to the pelvis (50 Gy in 25 fractions in 5 weeks) or mixed-beam external irradiation (three fractions a week of photons) to a total relative biologic effectiveness adjusted dose of 50 Gy over 5 weeks. All patients were scheduled to receive LDR intracavitary brachy-therapy. Of 146 evaluable patients, 80 were treated with mixed-beam irradiation and 66 with photons. Only 50% of the patients in the mixed-beam group and 75% in the photon group underwent brachytherapy. The local tumor control at 2 years was 45% in the mixed-beam group and 52% in the photon group. Severe complications occurred in 19% of the mixed-beam and 11% of the photon-beam patients (p <0.13). It was thought that the inferior outcome with neutrons may have resulted from the use of horizontal beams of varying energy and penetration.

Heavy Ions

Kato et al. (302) reported on 44 patients with locally advanced cervical cancer treated with carbon ion radiation therapy. Total whole pelvis dose was 52.8 to 72 Gy equivalent (GyE) in 16 fractions of 2.2 to 3 GyE and eight fractions local boost or 68 to 72.8 GyE (44.8 GyE and additional 24 or 28 GyE boost). The 5-year local tumor control was 45% and 79%, respectively. Eight patients developed major intestinal complications, which were surgically salvaged; they were associated with doses >60 GyE.

External-Beam Irradiation Alone

Occasionally, brachytherapy procedures cannot be performed because of medical reasons or unusual anatomic configuration of the pelvis or the tumor (i.e., extensive lesion, inability to identify the cervical canal). These patients may be treated with higher doses of external-beam irradiation alone, although treatment results are less than optimal.

Coia et al. (90), in an analysis of 565 patients with various stages of cervical carcinoma treated in the Patterns of Care Study, reported better survival (67%) and pelvic tumor control (78%) when patients were treated with external irradiation and brachytherapy compared with patients who had no intracavitary brachytherapy applications (36% 4-year survival and 47% in-field failure rates). Patients treated with two intracavitary applications had a higher 4-year survival rate (73%) and in-field tumor control rate (83%) than those receiving only one application (60% 4-year survival rate and 71% in-field tumor control rate).

Hanks et al. (228) and Montana et al. (417) reported a higher incidence of central pelvic recurrences in patients with stage III cervical carcinoma treated with external-beam therapy alone than in patients receiving brachytherapy in addition to external-beam irradiation (Table 66.19). The incidence of major complications was similar in both groups of patients.

Akine et al. (9) treated 104 patients with carcinoma of the uterine cervix with external irradiation alone (anteroposterior–posteroanterior or four-field box techniques) because of inability to perform intracavitary brachytherapy. Average doses delivered were 50 Gy to the whole pelvis, followed by additional doses with reduced portals to deliver a total of 60.8 Gy in 6 weeks, 72.3 Gy in 7.5 weeks, or 80.5 Gy in 8 weeks, with a daily dose of 1.9 or 2 Gy. The local tumor control rate was 27% for stage II, 19% for stage III, and 15% for stage IVA disease. The 5-year survival rates were 36%, 17%, and 5%, respectively. Four patients had major complications (usually proctitis) that required surgical treatment, and one patient died of rectal bleeding. Eight of 23 patients treated with conformal therapy

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had control of the tumor and survived 5 years without major complications.

Saibishkumar et al (540) treated 146 patients with cervix cancer with EBRT alone (60 to 66 Gy), because of unsuitability for brachytherapy; 5-year pelvic tumor control was 21.9% and DFS 11.6%.

Impact of Tumor Size on Outcome

Perez et al. (474), in an update of a previous report (476), reviewed 1,499 patients (stages IA to IVA) treated with definitive irradiation (combination of external-beam irradiation plus two intracavitary insertions to deliver doses of 70 to 90 Gy to point A). There was a close correlation between tumor size and extent with pelvic tumor control, incidence of distant metastasis, and disease-free survival in all stages. Eifel et al. (140), in a review of 1,526 patients with stage IB squamous-cell carcinoma of the uterine cervix treated with radiation therapy alone, noted pelvic tumor control in 97% of tumors <5 cm and in 84% of tumors 5 to 7 cm.

Impact of Prolongation of Treatment Time on Outcome

Several studies have described lower pelvic tumor control and survival rates in invasive carcinoma of the uterine cervix when the overall time in a course of irradiation is prolonged (115,167,179,350).

Fyles et al. (167) reported approximately 1% loss of tumor control per day of prolongation of treatment time beyond 30 days in 830 patients with cervical carcinoma treated with irradiation alone.

Lanciano et al. (350), in an analysis of 837 patients with squamous-cell carcinoma of the cervix from the Patterns of Care Study who were treated with irradiation and received doses of 66 Gy or greater, also described a 4-year actuarial in-field recurrence increase from 6% to 20% when total treatment time increased from 6 weeks or less to 10 weeks (p = 0.0001); this translated into significantly decreased survival.

Girinsky et al. (179), in 386 patients with stage IIB or III carcinoma of the cervix, also observed that the 10-year local recurrence–free survival rate decreased when overall treatment time exceeded 52 days. A 1.1% loss of pelvic tumor control per day was also observed in their regression analysis.

Perez et al. (473), in 1,330 patients treated with definitive irradiation, noted a major impact of prolongation of treatment time on pelvic tumor control in stages IB, IIA, and IIB (Fig. 66.27A,B). In stage III, although the rate of pelvic failure was higher with prolongation of treatment time, the difference was not statistically significant. There was also a strong correlation between overall treatment time and survival (Fig. 66.28A,B). Regression analysis confirmed previous reports that prolongation of overall treatment time resulted in an increased failure rate of 0.59% per day in stage IB and IIA and 0.86% per day in stage IIB disease. Performance of all intracavitary insertions within 4.5 weeks from initiation of irradiation yielded lower pelvic failure rates (8.8% vs. 18% in stage IIB tumors; p ≤0.01).

In patients treated with radiation therapy, overall treatment time should be as short as possible, and any planned or unplanned interruptions or delays should be avoided. Timely integration of external-beam and intracavitary irradiation in patients with carcinoma of the uterine cervix is an important factor in improving pelvic tumor control.

Metastases to Para-Aortic Lymph Nodes

Para-aortic lymph node metastases are frequently combined with distant dissemination but are clinically apparent in only 10% to 20% of patients who have recurrences.

Nelson et al. (437) reported on 104 patients with stage II and III cervical carcinoma who had exploratory laparotomy and para-aortic lymph node biopsies; 12.5% of patients with stage IIA disease, 14.9% with stage IIB, and 38.4% with stage III disease had para-aortic lymph node metastases. They were treated with 60 Gy to the para-aortic region. Within 4 years, 50% of these patients had distant metastases and only one out of 13 was alive. There was no significant increase in complications in the patients receiving para-aortic irradiation (39% and 32%). They concluded that the main goal of exploratory laparotomy and para-aortic lymph node biopsy is to define the extent of disease.

Lovecchio et al. (388) noted a 50% 5-year survival rate in 36 patients with stage IB and IIA cervical carcinoma who had histologically confirmed para-aortic lymph node metastases treated with RT (including 45 Gy to the para-aortic lymph nodes). Fourteen of 31 evaluable patients had pelvic recurrences (12 combined with distant metastases). Unfortunately, the authors did not specify how many patients had para-aortic recurrences, although they reported four abdominal failures.

Stryker and Mortel (585) determined survival after extended-field treatment of para-aortic lymph node metastasis plus brachytherapy or pelvic boost in 35 patients; 5-year survival was 41.7% for 12 patients with microscopic para-aortic lymph node metastasis and 26.1% for 23 with grossly enlarged lymph nodes. Three patients (8.6%) had grade 4 morbidity.

Grigsby et al. (199) reviewed 43 patients with cervical cancer and biopsy-proven positive para-aortic lymph nodes treated with external irradiation to the pelvis and para-aortic regions (45 to 50 Gy) combined with brachytherapy. The 5-year overall survival rate was 32%, and the cause-specific survival rate was 49%. Tumor recurrence occurred in 20 patients (three in the pelvis, nine in pelvis and distant metastasis, and eight

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distant metastasis only). Severe grade 3 complications occurred in two patients (one had an enterovaginal fistula and the other radiation myelitis).

Hacker et al. (216), in 437 patients with invasive cervical carcinoma, 222 treated with radical hysterectomy and lymphadenectomy, identified 34 in whom resection of bulky pelvic or para-aortic lymph nodes was carried out without a complete lymphadenectomy. Thirty-three patients received pelvic external irradiation, and 28 combined pelvic and para-aortic extended-field irradiation (50.4 Gy in 1.8-Gy fractions using a four-field technique). Four cycles of cisplatin were administered to 23 patients. The 5-year survival was 80% in patients with pelvic and common iliac nodes and 48% in those with positive para-aortic lymph nodes. Serious long-term morbidity occurred in six patients (18%). Radiation enteritis was observed in five patients, leading to small bowel obstruction necessitating resection.

Grigsby et al. (196) evaluated twice-daily external irradiation to the pelvis and para-aortic nodes (1.2 Gy at 4- to 6-hour intervals, 5 days per week) combined with brachytherapy and concurrent chemotherapy in 29 patients with carcinoma of the cervix and positive para-aortic lymph nodes. EBRT doses were 24 to 48 Gy to the whole pelvis, 12 to 36 Gy parametrial boost, and 48 Gy to the para-aortics with additional boost to a total dose of 54 to 58 Gy to known metastatic para-aortic sites. One or two LDR brachytherapy applications were performed to deliver a total dose of 85 Gy to point A. Cisplatin (75 mg/m2, days 1 and 22) and 5FU (1,000 mg/m2 per 24 hours for 4 days; days 1 and 22) were given for two or three cycles. Hyperfractionated external radiation therapy was completed in 86% (25/29). Radiation therapy toxicity was grade 2 in 34%, grade 3 in 21%, and grade 4 in 28%. An unacceptably high rate (31%, 9/29) of grade 4 nonhematologic toxicity was recorded. With a median follow-up of 18.9 months, at 2 years the overall survival rate was 47%, and the probability of locoregional failure was 49%.

Malfetano et al. (395) treated 67 patients with carcinoma of the cervix (44 with stage IIB and 23 with stage III disease) with cisplatin (1 mg/kg up to 60 mg weekly) and extended-field radiation therapy, including the para-aortic nodes, and brachytherapy; 75% were alive without evidence of disease with a mean follow-up of 47.5 months.

Chou et al. (82) treated 19 patients with isolated para-aortic lymph node metastasis from cervix cancer, 14 of them with chemoradiation, four with chemotherapy, and one with irradiation alone. Seven of the 14 patients receiving chemoradiation survived.

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Goodman et al. (183) compiled survival statistics on patients with para-aortic lymph node metastasis and found an average 5-year survival rate of approximately 40% (Table 66.20).

Elective Para-Aortic Lymph Node Irradiation

Rotman et al. (527) for the RTOG (527) updated results of a randomized study of 337 patients with stage IIB carcinoma of the uterine cervix with no clinical or radiographic evidence of para-aortic lymphadenopathy who, in addition to standard pelvic irradiation, were randomized to electively receive or not 45 Gy to the para-aortic region (1.6- to 1.8-Gy fractions). The 10-year survival rate was 55% for patients receiving elective para-aortic irradiation and 44% for those treated to the pelvis only (p = 0.02; Fig. 66.29). The locoregional tumor control rate was similar (69% in the para-aortic node–irradiated group and 65% for the pelvis-irradiated group). The 10-year grade 4 or 5 (major) complication rate was 8% in the group receiving para-aortic irradiation compared with 4% in patients treated with pelvic irradiation alone (p = 0.06).

A similar randomized study was reported by Haie et al. (219) and the European Organization for Research and Treatment of Cancer (EORTC) on 441 patients with cervical carcinoma, including stage III, who had no evidence of para-aortic lymph node involvement. In the study group, the para-aortic area either received or did not receive 45 Gy with external-beam irradiation. No statistically significant difference was found between the two treatment arms with regard to local tumor control, distant metastases, or survival. However, the incidence of para-aortic and distant metastases without pelvic failure was significantly higher in patients receiving pelvic irradiation alone. The incidence of small bowel injury was 0.9% in the pelvic irradiation and 2.3% in the pelvic and para-aortic

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irradiation groups. A severe complication rate of 9% was observed in patients receiving para-aortic irradiation compared with 4.8% in those treated to the pelvis only.

Sood et al. (571) treated 54 patients with cervix cancer using extended fields (45 Gy) and HDR BT; 44 received concurrent cisplatin (20 mg/m2 per day for 5 days during the first and fourth week and once after the second HDR insertion). During a median follow-up of 28 months, six patients had died. The 3-year local tumor control was a 100% and 85%, respectively. Late toxicity was 10% and 6%, respectively.

Adenocarcinoma of the Cervix

Several authors have reported similar survival rates for equivalent stages of adenocarcinoma or squamous-cell carcinoma; clinical stage, volume of disease, and dose of irradiation were the most important prognostic factors (200,315). Grigsby et al. (200) found no difference in 5-year DFS in patients with adenocarcinoma of the cervix compared with squamous-cell treated with RT alone or combined with surgery (Table 66.21).

Similar observations were reported by Eifel et al. (138) in 229 patients with stage IB
adenocarcinoma of the cervix. The 5-year survival rates were 72% versus 81% for squamous-cell carcinoma. The incidence of pelvic recurrence was similar (17% for adenocarcinoma and 13% for squamous-cell carcinoma). However, distant metastases were more frequent in patients with adenocarcinoma (37% vs. 21%; p <0.01). The survival rate in 165 patients who underwent adjuvant hysterectomy (78%) was not significantly different from that of patients who did not have a surgical procedure (71%).

Later Eifel et al. (141) studied 334 patients with adenocarcinoma of the cervix. The 5-year relapse-free survival and locoregional control rates were 88% and 94%, respectively, in 91 patients with a normal-sized cervix, 64% and 82%, respectively, in 102 patients with lesions 3 to 5.9 cm in diameter, but only 45% and 81% in 22 patients with tumors >6 cm in diameter.

Fifty-eight patients with adenocarcinoma of the cervix treated with LDR or HDR brachytherapy and external pelvic irradiation were studied by Nakano et al. (433). The 10-year survival rates for stages I, II, III, and IV were 85.7%, 60%, 27.6%, and 9.1%, respectively. The local tumor control rate with HDR treatment was 45.5%, significantly lower than with LDR (85.7%) or mixed–dose-rate treatments (72.7%).

Kilgore et al. (315), in a study of 162 patients with adenocarcinoma compared with matched patients with squamous-cell carcinoma, found that clinical stage and lesion size were the most important prognostic factors. In patients with stage I tumors, no significant difference in survival was found when they were treated with radical surgery, irradiation alone, or irradiation combined with hysterectomy.

In contrast, Kjorstad et al. (327) reported a worse 5-year survival rate in 102 patients with adenocarcinoma (51%) compared with that of 1,900 patients with squamous-cell or other differentiated carcinomas (68%).

Comparison of Low–Dose-Rate and High–Dose-Rate Brachytherapy Results

Randomized Studies

A few randomized studies have been published comparing HDR and LDR brachytherapy for carcinoma of the cervix (215).

A report by Shigematsu et al. (556), in patients with stage IIB or III disease treated with the HDR technique, showed higher 1-year local control (90%) with HDR versus 77% with LDR. The 5-year survival rate was 55% for both groups.

Another trial including patients with stage IB, IIA, IIB, and III disease by Gupta et al. (215) showed similar local tumor control rates for both HDR and LDR (80% and 85%, respectively). However, the stage distributions in each group and the survival and complication rates were not described.

Teshima et al. (603) reported on a prospective, randomized study of 430 patients with carcinoma of the uterine cervix treated with either LDR (171 patients) or HDR (259 patients) brachytherapy combined with external irradiation. Cause-specific and overall survival rates were comparable for each clinical stage with either modality, except for stage I overall survival (Fig. 66.30). The conversion factor of total intracavitary dose from LDR to HDR was 0.5 to 0.53. With HDR, four fractions usually were delivered, and with LDR two fractions. The incidence of pelvic failures was comparable in both groups. The incidence of grade 2 and 3 morbidity was somewhat higher in the HDR group (approximately 10%) than in the LDR group (4%; p = 0.002).

Patel et al. (463) published a randomized trial of 482 patients with invasive squamous-cell carcinoma of the cervix. The overall local tumor control rate with LDR brachytherapy was 79.7% compared with 75.8% with HDR. The 5-year survival rates were 73% with LDR and 78% with HDR in stage I, 62% and 64%, respectively, in stage II, and 50% and 43% in stage III. The only statistically significant difference was the incidence of overall rectal complications, which was 19.9% for LDR compared with 6.4% for HDR. However, the incidences of more severe grade 3 and 4 complications were not significantly different (2.5% and 0.4%, respectively). Bladder morbidity was similar in both groups.

Hareyama et al. (231) conducted a randomized study in 132 patients with stage II or IIIB cervical carcinoma treated with LDR or HDR BT and identical pelvic EBRT. The conversion factor from LDR to HDR was 0.588. The 5-year DSS with HDR for stage II and IIIB was 69% and 51%, respectively, and with LDR 87% and 60%, respectively. Pelvic tumor control was 89% and 73% and 100% and 70%, respectively, and grade 3 or

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greater morbidity was 10% and 13%, respectively (differences were not statistically significant).

Lertsanguansinchai et al. (373) randomized 237 patients with cervical cancer to be treated with LDR (109 patients) or HDR (112 patients) brachytherapy and EBRT. Median follow-up was 40 and 37 months, respectively. Three-year pelvic tumor control was 89% and 86.4% and relapse-free survival 69% in both groups. Grade 3 or 4 morbidity was noted in 2.8% of LDR and 7.1% of the HDR patients (p = 0.23).

Nonrandomized Studies

Many nonrandomized studies compared the results of HDR with those of historic or concurrent control patients receiving LDR at the same institution (21,87,165,180,247,289). Most studies used point A as a reference point, although the definition of point A may have differed from center to center.

HDR dose per fraction at point A was 3 to 10 Gy; the number of fractions ranged from two to 13, and the number of fractions per week varied from one to three. Most centers used a schedule of 6 to 7 Gy per fraction per week for four to six fractions.

Table 66.22 illustrates the 5-year survival rates of patients who received HDR or LDR brachytherapy combined with external-beam irradiation for carcinoma of the cervix. Stage for stage, 5-year survival rates of patients treated with the HDR technique are comparable with those of historic or concurrent nonrandomized patients treated with LDR.

In an analysis of 198 patients treated with LDR brachytherapy at the University of Wisconsin, the 3-year survival rate was 66% versus 77% for 40 patients treated with HDR brachytherapy (545). Pelvic tumor control rate were 80% and 77%, respectively. The incidences of complications requiring hospitalization or surgery were 10% (20/198) and 2.5% (1/40), respectively.

Petereit et al. (482) updated the University of Wisconsin experience with 191 patients receiving LDR brachytherapy and 173 receiving HDR brachytherapy with equivalent external-beam radiation therapy techniques. The results are summarized in Tables 66.23 and 66.24. Pelvic tumor control and survival rates were comparable with the two techniques, except in stage III; in this subgroup, outcome was better with LDR brachytherapy, but this may be related to a lower HDR equivalent dose administered.

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Le Pechoux et al. (359) treated 130 patients with cervical cancer with HDR brachytherapy (for stage I, 30 Gy in six weekly sessions) in combination with EBRT (50-Gy mean dose with midline shielding). Patients with more advanced disease received four sessions of biweekly brachytherapy for a total dose of 18 to 24 Gy and external irradiation (20 to 30 Gy to the whole pelvis, 50 to 66 Gy to parametria with midline shielding). The 5-year survival rates were 82% for patients with stage IIB and 47% with stage IIIB disease. There were four rectovaginal or vesicovaginal fistulas and one case of proctitis requiring colostomy. Survival, local tumor control, and morbidity were equivalent in 76 patients treated with 6 Gy once a week and in 54 patients receiving twice-weekly brachytherapy of 5 Gy per session.

Hsu et al. (266) treated 92 patients with cancer of the cervix with HDR brachytherapy, six fractions of 7 Gy per fraction (42 Gy) at point A (HDR-6); 57 received four fractions of 8 Gy per fraction (32 Gy) at point A (HDR-4). A twice-daily program was used for all patients receiving HDR in two split courses. A historic control group of 259 patients was treated with LDR brachytherapy (40 Gy in two split courses). All patients received whole pelvis external irradiation of 36 to 45 Gy (mostly 40 Gy) before brachytherapy. Five-year local tumor control rates were equivalent in the three groups (82%, 85.5% for HDR, and 89.5% for LDR). Five-year survival rates were also comparable (67.7%, 77.9%, and 74.1%, respectively). However, late complications were lower in the HDR-4 group, which received treatment more biologically equivalent to the LDR regimen, than in patients in the HDR-6 group (11% vs. 25.6%).

Selke et al. (548) published results in 187 patients with primary carcinoma of the cervix treated with whole pelvis irradiation (46 Gy) and HDR brachytherapy with a dose rate to point A of 1.6 Gy per minute, decreasing to approximately 0.8 Gy per minute at the end of the 5-year study. Three HDR fractions (8 to 10 Gy to point A per fraction) were concurrently administered with the last 2 to 3 weeks of external irradiation. The 5-year actuarial survival rates were 72% for stage IB, 65% for

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IIA, 66% for IIB, 66% for IIIA, and 45% for stage IIIB. With a median follow-up of 54 months, 23 patients had 25 complications; 13 (7.6%) were grade 3 or 4. Rectal complications were significantly higher in patients who received a total rectal dose higher than 54 Gy (p = 0.045).

Choi et al. (81) treated 136 patients with carcinoma of the cervix with external-beam whole pelvis irradiation (46 Gy in 23 fractions) and three weekly applications of HDR brachytherapy of 7 or 8 Gy per fraction to point A. The actuarial 5-year survival was 85% in stage IB, 64% in stage IIA, 70% in stage IIB, and 53% in stage IIIB. Grade 3 or higher complications occurred 3% to 7% of the patients. The most significant determinants of severe rectal complications were the addition of a lower vaginal tandem (p <0.01), uterine tandem length longer than 5 cm, a total biologically effective dose to the rectum of more than 120 Gy, or stage III disease.

Kagei et al. (290) reported on 217 patients with carcinoma of the cervix (71 patients with stage II and 146 with stage III disease) who received whole pelvis EBRT (40 Gy in 20 fractions or 39.6 Gy in 22 fractions) and an additional 10 Gy in five fractions to the parametria followed by HDR brachytherapy. Cause-specific 5-year survival rates were 77% for stage II and 50% for stage III. Pelvic failure rates were 13% and 36% respectively. The rates of severe (grade 4) late complications were 2% for the rectum, 1% for the small intestine or sigmoid colon, and 1% for the bladder.

Takeshi et al. (595) treated 265 patients with stage III cervical carcinoma with external-beam radiation therapy (50.3 Gy) and intracavitary HDR brachytherapy (19.8 Gy). The 5-year overall survival, relapse-free survival, and locoregional event–free rates were 50.7%, 57.1%, and 71.2%, respectively. The 5-year incidence of major complications was 2.6% for bladder and 8.3% for rectum. The radiation dose in the subgroup with rectal complications was significantly greater than that in the subgroup without complications.

Wang et al. (641) reported treatment results in 173 patients with cervical carcinoma treated with HDR brachytherapy, whole pelvis irradiation (40 to 44 Gy in 20 to 22 fractions) followed by pelvic wall boost (6 to 14 Gy in three to seven fractions with central shielding). HDR brachytherapy delivered 7.2 Gy to point A in each of three applications, 1 to 2 weeks apart. Five-year pelvic tumor control rates were 94%, 87%, and 72% for stages IIA, IIB to IIIA, and IIIB to IVA, respectively. Five-year actuarial survival rates were 79%, 59%, and 41%, respectively. Sixty-six (38%) had rectal complications and 19 (11%) bladder complications. The 5-year actuarial rectal complication rates were 15%, 4%, and 3% for grades 2, 3, and 4, respectively.

Potter et al. (499) reported results in 148 patients treated with HDR brachytherapy and EBRT (48.6 to 50 Gy). Small tumors were treated with five to six fractions of 7 Gy at point A (25 Gy in the brachytherapy volume), which is isoeffective to 76 to 86 Gy at point A. Large tumors received three to four fractions of 7 Gy after 50 Gy of EBRT, which is isoeffective to 82 to 92 Gy at point A. Three-dimensional treatment planning for brachytherapy was based on conventional x-rays, and in 181/189 patients on CT scan. The mean brachytherapy dose was 16.2 Gy at the ICRU rectum reference point and 14.4 Gy at the ICRU bladder point. Taking into account the dose for EBRT, the mean isoeffective dose at the ICRU rectum reference point was 69.9 Gy. After a mean follow-up of 34 months, the actuarial late complication rate for grades 3 and 4 was 2.9% for bladder, 4% for bowel, 6.1% for rectum, and 30.6% for the vagina (shortening and obliteration).

Lorvidhaya et al. (386) reported the results in 1,992 patients with carcinoma of the cervix treated by external irradiation and HDR brachytherapy. There were 211 with stage IB, 225 with stage IIA, 902 with stage IIB, 14 with stage IIIA, 675 with stage IIIB, 16 with stage IVA, and 16 (0.8%) with stage IVB. With a median follow-up of 96 months, the actuarial 5-year disease-free survival rates were 70%, 59.4%, 46.1%, 32.3%, 7.8%, and 23,1%, respectively. The late complication rates (RTOG) for bowel and bladder combined were 7% for grade 3 and 1.9% for grade 4 complications.

Leborgne et al. (362) described a 4-year pelvic control rate of 93%, and a disease-free survival rate of 88% for 59 patients with stage IB to IIA disease treated with 18 Gy whole pelvis and 22 Gy to the parametria combined with six HDR fractions (14 Gy per hour to point A) of 7 Gy to point A, two in each treatment day with 6-hour intervals. The corresponding parameters for 29 patients with stage IIB disease were 79%, 75%, and 75%. The actuarial 4-year late grade 2 and 3 complication rate was 4.7%.

Ferrigno et al. (154) carried out a retrospective study of 190 patients treated with LDR and 118 with HDR brachytherapy in combination with pelvic EBRT for cervical cancer. For stage I or II patients, there was no difference in outcome; however, in the stage III group local tumor control was 58% with LDR and 50% with HDR (p = 0.19) and DFS was 49% versus 37% (p = 0.03). At 5 years, rectal sequelae were 16% versus 8% (p = 0.03), bladder 6% and 3% (p = 0.13), and small bowel 4.6% and 8.9% (p = 0.17).

Nakano et al. (434), in 1,148 patients with squamous-cell cervical cancer treated with external RT and HDR brachytherapy with 22 years median follow-up, the 10-year pelvic tumor control was 93% for stage IB, 82% for stage II, and 75% for stage III. Cause-specific survival was 89%, 74%, and 59%, respectively. Major sequelae were 4.4% in the rectosigmoid, 0.9% in the bladder, and 3.3% in the small intestine.

Kapp et al. (298) analyzed 720 192Ir HDR applications in 331 patients with gynecologic tumors to evaluate the dose to normal tissues. The ratio of bladder-base dose to bladder-neck dose was 1.5 for intracervical and 1.46 for intravaginal applications. CT-assisted dosimetry showed that the maximum doses to bladder and rectum were generally higher than those

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obtained from orthogonal films, with an average ratio of 1.44 for the bladder neck, 2.42 for the bladder base, and 1.37 for the rectum. If conventional methods are used for dosimetry, the authors recommended that doses to the bladder base should be routinely calculated because single-point measurements at the bladder neck seriously underestimate the dose to the bladder. Also, the rectal dose should be determined at several points over the length of the implant because of the wide range of anatomic variations.

Wright et al. (664) developed a questionnaire to elicit patient preference for two brachytherapy methods (one LDR or three HDR fractions and two HDR or five HDR fractions, assuming both methods to be isoeffective). The questionnaire was completed by 90 female staff members at their center, 18 previously treated patients, and 20 newly diagnosed patients. When both methods were assumed to be isoeffective, only 34% of the 38 patients preferred three HDR fractions to one LDR fraction. However, when HDR was assumed to be 2% more curative or 6% less toxic, 50% said they would prefer the HDR therapy. Both preference and strength of preference for LDR were significantly associated with a greater traveling distance for treatments.
Studies on resource utilization, such as published by Bastin et al. (31), and cost-effectiveness comparing LDR and HDR treatment should be carried out. These considerations have more relevance as we continue to debate the cost–benefit issues of HDR brachytherapy and health care costs.

Irradiation after Radical Hysterectomy

Only one randomized study has shown improved survival with postoperative pelvic irradiation (46 to 50.4 Gy in 23 to 28 fractions) after radical surgery in the presence of positive pelvic nodes or node-negative high-risk factors in women with stage IB cervical cancer treated by radical hysterectomy and pelvic lymphadenectomy. There were 277 eligible patients with at least two of the following risk factors: greater than one-third stromal invasion, capillary lymphatic space involvement, and large clinical tumor diameter; 137 patients randomized to pelvic radiation therapy and 140 to no further treatment.

The results were updated by Rotman et al. (528); 24 (17%) patients in the irradiation group and 43 (30.7%) in the no further treatment group had cancer recurrences. In the radiation therapy group 27 patients died of cancer, and in the no further treatment group 40 died from cancer. There was a statistically significant reduction in risk of recurrence in the irradiation group, with recurrence-free rates at 2 years of 88% versus 79% for the irradiation and no further treatment groups, respectively. Overall survival difference did not reach statistical difference (p = 0.074) (Fig. 66.31). Severe or life-threatening (GOG grade 3 or 4) adverse effects occurred in nine patients (6.6%) in the radiation therapy group and three (2.1%) in the observation group.

SundfΦr et al. (588) conducted a randomized study in which 122 patients with stage IIA and 20 with stage IIB cervix cancer were treated with intracavitary radium followed by either radical pelvic surgery including lymphadenectomy (group A, 72 patients) or EBRT (40 Gy) to the pelvis (group B, 70 patients). Postoperative RT (40 to 50 Gy) was given to patients in group A found to have node metastasis at operation. Fourteen patients in group A and 23 in group B died of recurrent cancer. The 10-year survival was 84% and 69%, respectively.

Treatment techniques may have an effect on outcome. Yamazaki et al. (667) compared 34 patients with cervical cancer treated with irregularly shaped four-field whole pelvis radiation therapy using CT simulation and 40 patients receiving whole pelvis EBRT with parallel-opposed fields in a nonrandomized study of postoperative radiation therapy consisting of 50 Gy in 25 fractions in 6 weeks. With a mean follow-up of 60 months, the actuarial 5-year pelvic tumor control was 94% with the two-field technique and 100% for the irregularly shaped four-field technique. The incidence of grade 2 or 3 bowel complications in the irregularly shaped technique group (2.9%, 1/34) was significantly lower than that in the two-field technique group (17.5%, 7/40; p <0.05).

Burnett et al. (62) described a prosthetic silicone plastic device that is filled with saline and Renografin for x-ray visualization (capacity between 750 and 1,500 mL) to conform to the pelvis and exclude the small bowel from the irradiated volume. The device remains in place throughout the radiation therapy course and is removed through a small incision after draining the contents of the prosthesis. Seven devices had been placed to date of the report. In the postoperative period, there was one pulmonary embolism. All seven patients completed planned radiation therapy. The devices have been removed with no adhesions to the prosthesis.

Many nonrandomized reports on postoperative pelvic irradiation have been published (376,510); some are highlighted here.

Snijders-Keilholtz et al. (563) described results in 233 women who underwent radical hysterectomy for stage I or IIA cervical carcinoma; 156 were treated with surgery alone, and 77 received adjuvant radiation therapy for tumor-related high-risk prognostic factors. The most important prognostic factor for survival and disease-free survival was pelvic lymph node positivity; additional factors were depth of invasion and positive

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surgical margins. Twelve patients recurred after surgery alone, all in the pelvis (100%). Of the 23 recurrences after surgery and adjuvant radiation therapy, 13 were in the pelvis (56%; p = 0.003). Ten patients with poor prognostic factors and negative nodes received adjuvant radiation therapy, and none of these patients recurred. The incidence of severe gastrointestinal radiation-related side effects was 2%. The incidence of lymphedema of the leg was 11%, which was similar to that in the surgery-alone group.

Garipagaoglu et al. (173) investigated prognostic factors in 100 patients with stage IB or IIA cervical carcinoma treated with radical hysterectomy and postoperative irradiation. The 5-year overall survival, disease-free survival, and pelvic tumor control rates were 83.6%, 82.8%, and 91.8%, respectively. Pelvic lymph node metastasis (p = 0.008), interval between surgery and irradiation (p = 0.001), overall radiation therapy time (p = 0.007), and tumor size (p = 0.028) were significant factors for pelvic tumor control as well as for overall survival.

Kahousen et al. (291) reported on a GOG prospectively randomized, multicenter trial in which patients with stage IB or IIB cervical cancer treated with radical hysterectomy who had pelvic lymph node metastases or vascular invasion randomly received adjuvant chemotherapy (400 mg/m2 carboplatin, and 30 mg bleomycin), or external pelvic radiation therapy, or no further treatment. After a median follow-up of 4.1 years (range, 2 to 7 years), there were no statistically significant differences (p = 0.9539) in disease-free survival rates among the three treatment arms, suggesting that adjuvant chemotherapy or radiation does not improve survival or recurrence rates in high-risk patients with cervical cancer after radical hysterectomy.

Gonzales et al. (182) reported that in 89 patients with stage IB or IIA cervical cancer with positive lymph nodes receiving postoperative irradiation, the 5- and 10-year survival rates were 60% and 51%, respectively. By comparison, 43 patients with negative lymph nodes had a survival rate of 85%. In the surviving patients, there were four gastrointestinal and seven genitourinary severe complications requiring surgical correction. In four patients, asymptomatic stenosis of the ureters was detected by IV pyelography performed routinely every year.

Bianchi et al. (37), in 60 patients receiving external irradiation for pelvic node metastasis after radical hysterectomy, observed a 65% 5-year survival rate. In contrast, in 15 patients who refused postoperative irradiation, only three (20%) survived 5 years.

Chatani et al. (76) reported on 128 patients with stage T1B to T2B carcinoma of the cervix who underwent radical hysterectomy with bilateral pelvic lymphadenectomy and postoperative EBRT. The 5-year local and distant failure rates were, respectively, 2% and 12% for negative nodes, 23% and 25% for one positive node, and 32% and 57%, for two or more positive nodes (p = 0.0029 and p = 0.0051, respectively). The 5-year cause-specific survival rates were 90%, 59%, and 42%, respectively (p = 0.0001). The most common complication was lymphedema of the lower extremity, experienced by half of the patients (42% at 5 years and 49% at 10 years).

Uno et al. (624) evaluated results of postradical hysterectomy irradiation in 98 patients with stage IB to IIB cervical cancer; all the patients had at least one pathologic risk factor for pelvic recurrence. The 5-year overall survival was 82%. There were pelvic recurrences in five cases and distant metastases in 15 cases. The 5-year overall survival rates for patients with or without pelvic lymph node metastasis were 76% and 89%, respectively (p = 0.018).

Kinney et al. (323) compared results of therapy in 82 patients with stage IB or IIA carcinoma of the cervix found to have pelvic lymph node metastases at Wertheim hysterectomy and bilateral lymphadenectomy without additional adjuvant therapy with 103 similar patients who received 50 Gy to the pelvis after surgery. The 5-year survival rate was 72% for the surgery-only patients and 64% for the group receiving adjuvant irradiation. The incidences of pelvic recurrences were 67% and 27%, respectively. The lack of impact on overall survival in the irradiated patients is most likely related to a higher incidence of distant metastases, which may be a reflection of higher short-term survival and high-risk patient selection.

Kinney et al. (324), in 117 patients treated with radical hysterectomy and pelvic lymphadenectomy, noted histologically proven nodal metastatic disease in 51 patients (44%; squamous cell in 35 and nonsquamous in 16). Nodal involvement was bilateral in 24 patients (47%). Para-aortic lymph node dissection was performed in 14 patients, and five had tumor involvement. Postoperative pelvic irradiation was administered to 29/51 patients (51.2 Gy, two fractions). Extended fields to the para-aortic area were used in six patients. The 5-year survival rates were 33% for the group receiving irradiation and 50% for the not irradiated group. Only one patient treated with postoperative irradiation had a pelvic failure, in contrast to seven patients not irradiated.

Inoue and Morita (269) described results in 72 patients treated with extended-field irradiation after radical surgery for nodal metastases from cervical cancer stage IB (37 patients), IIA (six patients), and IIB (29 patients). The median dose to para-aortic lymph nodes was 43.5 Gy and to the pelvis 45 Gy. The 5-year disease-free survival rates were 72% in 61 patients with squamous-cell carcinoma and 27% in 11 patients with nonsquamous-cell carcinoma. The 10-year disease-free survival rates were 88% for 22 patients with one positive node, 67% for 15 with two or three positive nodes, 64% for 16 with four to 17 positive nodes, and 20% for 10 patients with unresectable lymph nodes. Nineteen severe complications occurred in 17 patients; five were attributed to surgery, five to irradiation, and nine to both modalities. Four patients (5%) died of severe complications. Another six patients (8%) underwent major abdominal surgery for rectovaginal and ureterovaginal fistulas.

Mitsuhashi et al. (414) described an analysis of 108 patients with carcinoma of the cervix treated with postoperative EBRT to the pelvis followed by intravaginal cone boost with electron beam to the vaginal cuff. The 5-year cause-specific survival rates were 89% for 89 patients undergoing elective radiation therapy and 56% for 19 patients undergoing salvage irradiation (p <0.001). Recurrent tumors at the vaginal cuff were observed in only two patients in the elective irradiation group. Vesicovaginal fistula developed in four patients; only one patient had grade 2 rectal complications.

It appears that a modest gain in survival may be observed in patients with pelvic lymph node metastasis from carcinoma of the uterine cervix who receive irradiation after various types of surgery (182,526). More recently, studies involving a comparison of radiation versus radiation with chemotherapy have addressed this issue and are discussed later.

Postoperative Intracavitary High–Dose-Rate Brachytherapy

HDR brachytherapy after surgery is particularly suited for patients with cervical cancer because it prevents the prolonged immobilization required for LDR brachytherapy. In some patients at higher risk for parametrial tumor or lymph node metastases, HDR brachytherapy is combined with external-beam pelvic irradiation (20 Gy to the whole pelvis and additional 30 Gy to the parametria with midline shielding tailored to the geometry of the brachytherapy applications).

Hart et al. (234) described results in 83 patients who received postoperative RT for early stage cervical cancer with positive surgical margins, positive pelvic or para-aortic lymph nodes, lymphovascular space invasion, or deep stromal invasion, or for disease discovered incidentally at simple hysterectomy. Twenty-eight patients were treated with LDR brachytherapy with or without EBRT and 55 with EBRT to the pelvis and HDR intracavitary. Of these 83 patients, 66 were evaluable (20 LDR and

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46 HDR patients). Mean follow-up time was 101 months for the LDR group and 42 for the HDR group. The 5-year disease-free survival rate was 89% and 72%, local tumor control was 90% (18/20) and 89% (41/46), respectively. Three of 20 (15%) patients receiving LDR and 4/46 (9%) receiving HDR experienced grade 2 or 3 late treatment-related complications. No patient in either group had grade 4 or 5 complications.

Busch et al. (63) studied the outcome of 68 patients with cervical carcinoma—48 treated with radical hysterectomy and, because of risk factors, with postoperative RT (group 1), and 20 patients (group 2) pretreated with standard hysterectomy—admitted to the hospital for postoperative radiation therapy of the whole pelvis. Postoperative pelvic RT consisted of 39.6 Gy (box technique) and 6-Gy external-beam therapy to the pelvic lymph nodes, sparing the midline plus two HDR applications (7.5 Gy each), and survival, locoregional tumor control, and metastatic disease rates were nearly identical in both groups. Patients with positive lymph nodes had a worse prognosis (75% 3-year survival rate).

Atkovar et al. (25) described results in 126 patients treated with postoperative irradiation (median of 50 Gy in 5 weeks); 37 received vaginal cuff HDR brachytherapy (three fractions of 8 to 10 Gy at 5 mm, weekly). Overall and disease-free survival and locoregional tumor control rates were 71%, 69.9%, and 78.1%, respectively. Grade 2 and 3 complications developed in 5.5% of patients. Survival was the same in 67 patients treated with total abdominal hysterectomy and bilateral salpingo-oophorectomy and in 59 patients treated with radical hysterectomy and pelvic lymphadenectomy.

66_02 tecniche di radiot 02

Brachytherapy

Several isotopes are available, although at present cesium-137 (137Cs) is the most popular LDR source and iridium-192 (192Ir) for HDR. Brachytherapy can be delivered with intracavitary techniques using a variety of applicators consisting of an intrauterine tandem and vaginal colpostats or, when necessary, vaginal cylinders, the majority of which are afterloading. Radiographs are always obtained using dummy sources, and the active sources can be inserted after the films have been reviewed and the position of the applicators judged to be satisfactory (Fig. 66.16). The vaginal packing is soaked in 40% iodinated contrast material to identify it on the radiographs.

Nag et al. (431) carried out a survey of brachytherapy practice for cervical cancer in the United States in 1995; of 521 responses, 206 (40%) did not perform any brachytherapy for

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carcinoma of the cervix. For LDR treatments, the median pelvic EBRT dose was 45 to 50 Gy and the LDR brachytherapy dose was 42 and 45 Gy for early and advanced cancers, respectively. For HDR treatments, the median EBRT dose was 48 to 50 Gy and the median HDR dose was 29 and 30 Gy for early and advanced cancers, respectively. The median HDR dose per fraction was 6 Gy with a median of five fractions. Interstitial brachytherapy was used as a component of treatment in 6% of the patients by 21% of responders.

With regard to prescribing the doses, it is noteworthy that in 91 LDR applications with Fletcher-Suit applicators, Potish et al. (495) used linear least-squares regression to show that although there was a moderately good correlation between the milligram hours and dose to point A, it was markedly affected by the position of the colpostats and the tandem, making it difficult to formulate a simple conversion factor between the two systems. Therefore, computer-generated dose distributions provide the best means of determining the doses to point A, point B, bladder, and rectum. ICRU Report 38 (271) defines the dose and volume specifications for reporting intracavitary therapy in gynecologic procedures.

Basic principles of the clinical application of brachytherapy and use of remote afterloading devices (LDR or HDR) are discussed in Chapters 19, 20, 21, and 22. In general, an intrauterine tandem with three or four sources [15 or 20-10-10-(10) mCi mgRaEq with LDR] is inserted in the uterus and two colpostats (2 cm in diameter, loaded with 20 mCi mgRaEq LDR sources) are placed in the vaginal vault and packed with iodoform gauze to deliver 0.6 to 0.8 Gy per hour to point A.

If the vaginal vault is narrow, it may be impossible to insert regular-sized colpostats, in which case miniovoids should be used (usually loaded with 10 mCi mgRaEq LDR sources).

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Special attention should be paid to obtain as symmetric and homogeneous dose distribution as is technically allowed by the geometry of the cervix/vagina and the configuration of the tumor. When even miniovoids cannot be inserted, it is better to use a protruding source in the vaginal vault, which is inserted in the afterloading tandem (usually 20 to 30 mCi mgRaEq) with an overlying plastic sleeve (3 cm in diameter).

With HDR intracavitary applicators the use of a rectal retractor has been shown to substantially reduce the rectal dose (455). Lee et al. (368), in a study of 15 patients, found that this reduction was significant only in the subgroup who received >70% of the prescription dose (p <0.05).

Interstitial implants with radium-226 (226Ra), 137Cs needles, or 192Ir afterloading plastic catheters to limited tumor volumes are helpful in specific clinical situations (e.g., localized residual tumor, parametrial extension; Fig. 66.17). The use of Syed-Neblett and the Martinez perineal applicators has been discussed in Chapter 66. A ring applicator modified to allow simultaneous insertion of interstitial needles was described (325).

The American Association of Physicists in Medicine (13) and the American Endocurietherapy Society (656) recommend the air-kerma strength (measured in free space) to express source strength; the units are cGy•cm2•h-1 for LDR and cGy•cm2•s-1 for HDR sources:

• 1 Uh = 1 unit of air-kerma strength for LDR sources

• 1 mgRaEq = 8.23 Uh

• 1 Us = 1 unit of air-kerma strength for HDR sources

Further, the American Endocurietherapy Society recommended that mgh and mgRaEq be replaced by the integrated reference air-kerma.

As Fletcher (160) emphasized, conditions for an adequate intracavitary insertion include the following:

• The geometry of the insertion must prevent underdosing around the cervix;

• Sufficient dose must be delivered to the paracervical areas; and

• Vaginal mucosal (and, we add, bladder and rectal) tolerance doses must be respected.

Katz and Eifel (304) quantified the M.D. Anderson criteria for acceptable implant geometry to relate intracavitary brachytherapy prescription to Manchester and ICRU reference doses in measurements from films of 808 intracavitary applications, and correlated these parameters with outcome in 396 patients who completed definitive treatment for cervical cancer. The median distance from the tandem to the sacrum was 4 cm, or one-third the distance from the pubis to the sacrum. The distance between the vaginal ovoids and cervical marker seeds was 7 mm,

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and the median distance between the tandem and the posterior edge of the ovoids was 50% of the ovoid length. In 92% of insertions, vaginal packing was posterior to or within 5 mm of a line that passed through the posterior edge of the ovoids, parallel to the tandem. The median doses to point A and rectal, bladder, and vaginal surface reference points were 87 Gy, 68 Gy, 70 Gy, and 125 Gy, respectively. The average ratios between the doses at bladder or rectal reference points and point A were somewhat greater when smaller vaginal applicators were used. There was no significant correlation between the doses to standard reference points and the rates of central recurrence or major complications.

Haie-Meder et al. (222) and Potter et al. (498) published explicit recommendations from the gynecological GEC ESTRO working group for dose prescription and specification of brachytherapy in cervix cancer based on volume parameters defined by 3D–image-based anatomy, physics, and radiobiology principles (Fig. 66.18). Specifications include dose to gross tumor volume (GTV), CTV, and pelvic organs at risk. The linear quadratic model is applied to both brachytherapy (BT) and external beam RT calculations. Lang et al. (353), in a multicenter study, confirmed the feasibility of these recommendations, with total doses to point A from both BT and EBRT, ranging from 85 to 91 Gy and to CTV within 69 to 73 cGy. Doses to organs at risk were comparable to those obtained with standard dosimetric methods, more accurately determined in dose–volume histograms.

Dose Rate Impact on Outcome

Haie-Meder et al. (220), in 204 patients with cervical cancer randomized to receive one of two preoperative LDR brachytherapy (0.4 or 0.8 Gy per hour), noted similar local tumor control (93%) and overall survival (85%) rates at 2 years with either dose rate. Grade 3 late complications were observed in 7% of patients treated with 0.4 Gy per hour and in 13% of patients treated with 0.8 Gy per hour. There was one small bowel obstruction in the 0.4 Gy per hour group (1%) in contrast with five (5%) in the 0.8 Gy per hour group. Vesicovaginal fistulas were observed in 2% and 4%, respectively.

Fowler (162) analyzed results in 270 patients with carcinoma of the cervix treated with either 75 cGy per hour from manually loaded cesium or 150 cGy per hour by remote afterloading (440). There was an increase in grade 3 late complications from 4% to 22%, in spite of a reduction of 20% in dose, implying a rather large difference in biologic effect between the two systems. The effect of the increased dose rate was also described by Leborgne et al. (360). A Linear quadratic modeling was used to calculate biologically effective doses in the clinical protocols used. When the LDR was doubled, it was called medium dose rate (MDR). The maximum ratios calculated for the biologic effective doses of 16 Gy at MDR to 20 Gy at LDR were 1.06 to 1.15, assuming α/β = 4 to 2 Gy, the latter being an unlikely extreme for rectal or urinary complications. The theoretically ideal dose reduction factors, calculated using the t1/2 values derived from the clinical data, are in the range of 24% to 29% instead of 20%.

Rodrigus et al. (517) analyzed late complications in 143 patients with cervical cancer treated with two different brachytherapy schedules and external radiation. Seventy-seven patients had two intracavitary applications with a dose rate 0.54 Gy per hour and 66 patients with 1.07 Gy per hour. Because of the expected increase in complications with higher dose rate, the latter dose per application was reduced from 25 Gy to 20 Gy. Late intestinal and urinary complications were scored in 49/77 patients and in 46/68, respectively. Actuarial estimates at 5 years showed 42% and 54.1% late intestinal complications and 16.9% and 24.1% late urinary complications, respectively. Thus, despite the dose reduction, there was a clear dose rate effect on late morbidity. These studies emphasize the importance of dose rate of brachytherapy in carcinoma of the cervix.

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Low–Dose-Rate Brachytherapy

Intracavitary brachytherapy, with its rapid dose fall-off as a function of distance, yields a high dose to the uterus and paracervical tissues, but it is inadequate to treat the pelvic lymph nodes, and external irradiation is necessary to supplement the parametrial dose.

Rotmensch et al. (530) compared the outcome in 140 patients with early stage cervical cancer undergoing whole pelvis radiation therapy with one versus two LDR intracavitary brachytherapy applications. The two groups had similar 5-year local tumor control (p = 0.83), disease-free (p = 0.23), and cause-specific (p = 0.29) survival. Late complications were similar in the two groups. These results support the use of a single LDR application in patients with early stage disease undergoing definitive radiation therapy when 45-Gy external-beam pelvic irradiation is administered.

Perez et al. (474), in a retrospective analysis, noted that in patients with cervical cancer treated with radiation therapy alone for stage IB tumors <2 cm in diameter, the pelvic failure rate was under 10% with LDR doses of 70 to 80 Gy to point A, whereas for larger lesions, even doses of 85 to 90 Gy resulted in 25% to 37% pelvic failure rates. In stage IIB with LDR doses of 70 Gy to point A, the pelvic failure rate was approximately 50% compared with 20% in nonbulky and 30% in bulky tumors with doses >80 Gy. In stage III unilateral lesions, the pelvic failure rate was approximately 50% with 70 Gy or less to point A versus 35% with higher doses, and in bilateral or bulky tumors it was 60% with doses <70 Gy and 50% with higher doses.

Careful assessment of the quality of brachytherapy and dose distributions is critical. Suyama et al. (589) analyzed the minimal radiation dose to the peripheral area of the cervix in relation to local tumor failure using CT images taken at the time of intracavitary brachytherapy in 80 patients with carcinoma of the cervix. After CT scanning, isodose curves were superimposed on the CT images. Histograms of both the minimum percentage peripheral dose and the dose to the cervical area showed significant correlation in the local tumor control and local failure groups (p <0.001).

Biology of High–Dose-Rate Brachytherapy for Cervical Carcinoma

To achieve tumor control using HDR equivalent to that with LDR brachytherapy, attention to the dose/fractionation schedule and to normal tissue doses is mandatory (165,223,455). In general, the α/β values for tumor and early responding tissues is approximately 10 (Gy10), and for late-responding tissues 3 to 5 (Gy3-5) (480). The values derived are not actual doses but biologically effective ones that take into consideration dose rate and impact of fraction size.

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Orton et al. (455) suggested an LDR-to-HDR reduction factor of 0.54 to 0.6 (Table 66.13). Patel et al. (463) calculated a similar correction factor of 0.58. These conversion factors are valid when three to five HDR fractions are used, but with a higher number of fractions (six to eight), the conversion factor is closer to 0.75.

Figure 66.19 illustrates late normal tissue effect, which is proportional to log cell kill, and the relationship to the number of HDR treatment fractions (163). Each full curve is calculated assuming the same log cell kill. Late damage rises sharply as the number of HDR fractions is decreased. When these curves are above the dashed lines that represent the maximum late effect of 70 Gy of LDR brachytherapy given at 0.5 Gy per hour, the risk of late complications increases. Displacing the bladder and rectum away from the HDR sources for the short duration of therapy may offset the radiobiologic disadvantage of using a few brachytherapy fractions (455).

Clinical Experience

There is increasing use of HDR sources in brachytherapy of carcinoma of the cervix; basic principles of brachytherapy are similar to those of LDR (642). At Washington University, patients are treated with HDR brachytherapy with a tandem or a vaginal cylinder, which is placed in the patient before each treatment with sedation and without anesthesia. An indwelling bladder catheter is used during the procedure, and gentle packing of the vagina with iodoform gauze helps to maintain the applicators in place. Their position is verified with anteroposterior and lateral pelvic radiographs taken before the actual HDR treatment in each application. The usual dose per fraction prescribed at 0.5-cm depth is 3 to 6 Gy, and three to six fractions are given once or twice weekly.

No randomized trials in the United States have compared HDR and LDR brachytherapy for cervical cancer, although some have been carried out in other countries (as described later). Each center has developed unique HDR treatment schedules, dose specification systems, and time–dose fractionation protocols that reflect their understanding of radiobiologic issues and their patient population base (5,247,520).

Roman et al. (520) do not use central blocking for any stage; at institutions that use a central block, a 5-HVL block is most commonly used. Wayne State University uses a step-wedge central shielding method (5). Most HDR insertions are performed weekly and are interdigitated by giving four fractions of EBRT per week with one HDR treatment per week (Fig. 66.20).

Treatment schedules integrating external-beam irradiation and brachytherapy were initially designed with regard to the disease stage and volume by Arai et al. (21). The number of HDR fractions used to treat cervical cancer varies among centers from as few as two to more than 10. The optimal time–dose–fractionation scheme and the technique for remote-control

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afterloading intracavitary brachytherapy for cervical cancer have yet to be established through systematic clinical trials (429).

El-Baradie et al. (149) published a prospective study in which 45 patients with carcinoma of the uterine cervix were randomly allocated to either HDR or MDR. The external-beam radiation dose was the same in the two groups. The point A dose rate correction factor from LDR to HDR was 0.53, and from LDR to MDR 0.6. The 3-year survival and locoregional tumor control rates for both modalities were equivalent (62% and 67% for HDR and 68% and 74% for MDR). The rectal and bladder complication rates were the same in both groups (29% at 3 years). Tanaka et al. (596) also compared HDR and MDR brachytherapy in 150 and 56 patients, respectively. The survival was equivalents in the two groups; grade 2 or greater late toxicity tended to be higher in the HDR group (14% vs. 6%, respectively)

Orton et al. (455) noted that dose per fraction of HDR brachytherapy significantly influenced toxicity: Morbidity rates were highly significantly lower for point A doses/fractions of 7 Gy or less for both severe (1.28% vs. 3.44%; p <0.0001) and moderate plus severe injuries (7.58% vs. 19.51%; p <0.001). The effect of dose/fractionation on cure rates was equivocal.

Wayne State University uses a highly fractionated brachy-therapy course with eight to 12 HDR fractions (5), which was chosen to keep the rectal dose for each HDR fraction to 2 to 2.5 Gy. The intracavitary technique uses an intrauterine stent so that applicators can be placed quickly without cervical dilatation and using little or no sedation. Treatment planning is performed on the initial insertion and is duplicated for all fractions by verifying the applicator position with fluoroscopy or radiographs.

Petereit et al. (482) uses 45 Gy in 25 fractions for external-beam irradiation to the pelvis combined with five HDR fractions (5.5 to 6 Gy per fraction) or four HDR fractions (6.5 to 7 Gy per fraction). The equivalent LDR brachytherapy at point A is 80 Gy with 67 Gy delivered to the bladder or the rectum, assuming these tissues receive 70% of the prescribed point A dose. For advanced stages, such as IIB or IIIB, the intracavitary dose may be increased to 7.5 Gy per fraction, to give an LDR equivalent dose of 85 to 90 Gy to point A. Petereit and Pearcey (480), based on their preliminary results and published reports in the literature, recommend the doses and fractionation schedules summarized in Tables 66.14 and 66.15.

Kuipers et al. (340) described a method to improve target coverage and locoregional tumor control with HDR tandem and ovoid applications, whereby HDR endocavitary and interstitial brachytherapy are applied in the same session for tumors with a lateral expansion of 25 mm or more from the axis of the cervical canal. Seventy-six combined applications were given to 41 patients. With a follow-up average of 23 months, in stage IIB tumors, 3-year DFS was 75%. No severe early or persistent late complications were observed.

Dose Specifications for High–Dose-Rate Brachytherapy

Dose specification reporting systems for HDR brachytherapy vary by institution. However, many combine the Tod and Meredith point A as a paracervical dose with ICRU Report 38 on bladder and rectal points (271). In vivo bladder and rectal dosimetry is performed during the HDR procedure by Roman et al. (520). Other centers obtain normal tissue doses from points located on dosimetry films and dose distribution curves.

Treatment planning for HDR brachytherapy can be accomplished by a variety of techniques, ranging from use of an atlas of applications and source loadings, to planning of only the initial insertion followed by replicating the insertion for subsequent treatments, to customized optimization of source loading for each HDR insertion (21). Himmelmann et al. (247) described individualized computer treatment planning and a reconstruction system used to achieve individual dosimetry. Computerized optimization of source position and the dwell time for each position is a potential advantage of HDR brachytherapy that can provide customized treatment planning on a case-by-case basis. However, customized optimization is not commonly performed because it increases the time needed for planning and requires experience on the part of the physics and dosimetry staff (605).

Three-Dimensional Brachytherapy Treatment Planning

Fellner et al. (153) compared treatment planning for cervical carcinoma based on CT sections and 3D dose computations, or, when these techniques were not available, dose evaluation based on orthogonal radiographs. The CT-based planning provides information on target and organ volumes and dose–volume histograms. The radiography-based planning provides dimensions and doses only at selected points. For the study, 28 patients with 35 applications receiving HDR treatment with 192Ir

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were investigated. For a dose prescription of 7 Gy at point A, 83% (44 cm3) of the CTV received at least 7 Gy.

Eich et al. (137), in 11 applications of HDR brachytherapy for cervical carcinoma, calculated doses to ICRU bulletin points on orthogonal radiographs, and the doses at rectum reference points were compared with in vivo measurements. The in vivo measurements were 1.5 Gy below the doses determined for the ICRU rectum reference point (4.05 ± 0.68 Gy vs. 6.11 ± 1.63 Gy). The advantages of in vivo dosimetry are easy practicability and the possibility to determine rectal dose during radiation. The advantages of computer-aided planning at ICRU reference points are that calculations are available before radiation and they can be taken into account for treatment planning.

Gebara et al. (175) estimated the external, internal, and common iliac dose rates using 3D CT-based dose calculations in tandem and ovoid brachytherapy in 30 patients with carcinoma of the uterine cervix treated with LDR brachytherapy using a CT-compatible Fletcher-Suit-Delclos device. Thirty-six implants were performed, and the authors concluded that the point B dose is similar to the maximum common iliac nodal dose.

DeWitt et al. (119), in 15 patients with cervical cancer, defined target and organs at risk for planning of HDR brachytherapy and established guidelines for volume and dose constraint parameters using image-guided inverse treatment planning. Pelloski et al. (468) compared CT-based volumetric calculations and ICRU reference point radiation doses in 60 patients with cervix cancer treated with LDR brachytherapy. Of 118 insertions performed, 93 were evaluated and the minimal dose delivered to the 2 or 3 cm of bladder or rectum (DBV2 and DRV2, respectively) were determined on dose–volume histogram (DVH). They concluded that the ICRU dose was a reasonable surrogate for the DRV2 but not for the DBV2. Furthermore, these calculations may not be applicable to other treatment guidelines or intracavitary applicators.

Dose Fractionation in High–Dose-Rate Brachytherapy

The relationship between dose and fractionation for HDR and LDR intracavitary irradiation of stage I and II carcinoma of the cervix was examined by Arai et al. (22). The dose rate at point A was 2 to 3 Gy per minute (120 to 180 Gy per hour) for HDR and 0.6 to 0.9 Gy per hour for LDR irradiation. Concurrent EBRT was given to the whole pelvis (23 to 30 Gy) followed by 25 to 30 Gy with central shielding, along with brachytherapy. They concluded that the optimal dose fractionation schedules for HDR brachytherapy were 28 ± 3 Gy in four to five fractions, 34 ± 4 Gy in eight to 10 fractions, or 40 ± 5 Gy in 12 to 14 fractions at point A.

The importance of adopting biologically based equivalent doses when switching from LDR to HDR brachytherapy is exemplified in a report by Newman (440) on 115 patients treated with external irradiation (40 to 50 Gy) and manual afterloading cesium sources delivering 60 Gy to point A with a dose rate of 0.75 Gy per hour, or a Selectron device with 40-mCi sources, which delivered from 0.75 to 1 Gy per hour to point A. Because of the increased dose rate, the total intracavitary dose was reduced by 20%. Grade 3 genitourinary and gastrointestinal complications were observed in three of 87 patients (3.4%) treated with LDR, in contrast to 30/132 patients (22.7%) treated with the Selectron HDR sources. No significant differences in local tumor control and survival were found.

Chatani et al. (74) described a study in which 165 patients with carcinoma of the cervix were randomized to a HDR brachytherapy point A dose of 6 Gy (group A) or 7.5 Gy (group B) per fraction, both combined with external irradiation. The 5-year local failure rate was 16% in both groups, and distant failure rates were 23% and 29%, respectively (p = 0.2955). Moderate to severe complications requiring treatment were comparable (six patients, 7%) in the two groups.

Hama et al. (225) compared the effectiveness and safety of once versus twice-weekly HDR brachytherapy for cervical cancer in 124 patients treated with EBRT (50 Gy); 74 patients (group A) were treated with one HDR brachytherapy insertion weekly (three fractions of 7 Gy each to point A), and 50 patients (group B) were treated twice weekly (six fractions of 4.5 Gy each to point A). Overall survival rates were 65.2% and 65.3%, respectively (p = 0.96). Local recurrence-free survival rates were 69% for group A and 90% for group B (p <0.001). The rate of grade 2 (moderate) and grade 3 (severe) complications was significantly lower for group B (6%) versus 32% in group A (p <0.001).

Mayer et al. (405) compared HDR BT in two schedules to treat 210 patients with cervix cancer, one sequential (SRT) consisting of four fractions of 8 Gy followed by EBRT or continuous (CRT), consisting of five fractions of 6 Gy one session per week integrated with EBRT (four fraction per week). Total dose to point A was 68 to 70 Gy. Progression-free survival was 71% with CRT versus 56% with SRT (p = 1.0). Late bladder and rectal morbidity were 13% in the CRT and 25% in the SRT groups (p = 0.037), related to the higher dose per fraction (8 Gy).

Nam and Ahn (435) also compared, in a randomized study of 46 patients, two schedules of HDR BT (10 fractions of 3 Gy or five fractions of 5 Gy) followed by a small BT boost to residual tumor, in combination with EBRT (30.6 Gy to whole pelvis and 14.4 Gy to parametria with midline block). Three-year pelvic tumor control was 90% in both groups and disease-specific survival (DSS) 90.5% and 84.9% (p = 0.64), respectively. Late grade 2 or greater bladder or rectal morbidity was 23.8% and 9.1% (p = 0.24).

Liu et al. (381), based on the linear-quadratic model, developed isoeffect tables to convert traditional LDR doses and number of fractions to point A to HDR brachytherapy; depending on dose rate, different dose values can be calculated for various fractionation schedules. They predicted that, using therapeutic gain ratio, similar results would be obtained with either brachytherapy modality with two to four fractions of LDR and four to seven fractions of HDR.

The optimal time–dose–fractionation scheme for HDR brachytherapy for cervical cancer has yet to be established. The American Brachytherapy Society published recommendations

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for HDR brachytherapy for carcinoma of the cervix (429). Each institution should follow a consistent treatment policy, including complete documentation of treatment parameters and correlation with clinical outcome (pelvic tumor control, survival, and complications). The goals are to treat point A to at least a total LDR equivalent of 80 to 85 Gy for early stage disease and 85 to 90 Gy for advanced-stage disease. The pelvic sidewall dose recommendations are 50 to 55 Gy for early lesions and 55 to 65 Gy for advanced ones. As with LDR BT, every attempt should be made to keep the bladder and rectal doses below 80 Gy and 75 Gy LDR-equivalent doses, respectively. Interstitial brachytherapy should be considered when the tumor cannot be optimally encompassed by intracavitary brachytherapy. Some suggested dose and fractionation schemes for combining the external-beam radiation therapy with HDR brachytherapy for each stage of disease were presented, although they have not been thoroughly tested. It was emphasized that the responsibility for the medical decisions ultimately rests with the treating radiation oncologist.

Petereit and Pearcy (480), in a review of 24 HDR dose fractionation schedules published in the past three decades, found no dose relationship for either tumor control or late morbidity. They recommend that in the future all HDR publications for treatment of cervical cancer provide accurate and detailed fractionation and total-dose information. For additional discussion, see Chapters 21 and 22.

Results with Pulse–Dose Rate Brachytherapy

Rogers et al. (519) treated 52 patients with cervical carcinoma, 31 of which had staging laparotomy before radiation therapy. Brachytherapy was interstitial in 18 patients and intracavitary in 28. The median EBRT pelvis dose was 45 Gy in 25 fractions. Median total doses were 75.8 Gy to the implant volume with interstitial and 84.1 Gy to the A points with intracavitary at a median dose rate of 0.55 Gy per pulse per hour. Six patients had laparotomy-documented para-aortic node involvement and received EBRT to this site (45 Gy in 25 fractions). Thirty patients received concomitant weekly cisplatin chemotherapy (40 mg/m2). With a median follow-up of 25 months, the actuarial 4-year disease-free survival rates were 66% for the entire group (100% for stage IB, 69% for stage II, 68% for stage III/IVA, and 43% in patients treated for recurrences after surgery). Grade 4 complications occurred in two patients (4.3%). One patient (2.2%) had a grade 3 complication (frequent hematuria), and five (10.9%) had grade 2 complications.

Doses of Radiation

Stage IA (microinvasive) tumors are treated with intracavitary therapy only (LDR 60 Gy in one insertion or 75 to 80 Gy in two insertions to point A, or HDR 35 to 42 Gy in five to six insertions of 7 Gy to point A, one or two fractions per week).

The optimal dose for invasive carcinoma of the cervix is delivered with a combination of EBRT whole pelvis, intracavitary, and, at times, interstitial therapy. Some institutions such as ours use lower doses of whole pelvis external irradiation (10 Gy for stage IB and 20 Gy for stages IIA, IIB, and III) in addition to parametrial doses to complete 50 Gy in stage IB and IIA or 60 Gy to the involved parametrial tissues for more advanced stages. At Washington University, step-wedges designed in accordance with the isodose curves of the intracavitary applications are used to block the midline (Fig. 66.21). The LDR intracavitary insertions, usually two, deliver 7,000 to 7,500 mgh (65 to 70 Gy to point A) in stage IB tumors and 7,500 to 8,000 mgh (68 to 70 Gy to point A) for stage IIA, IIB, and III tumors. This technique affords a high central dose to the cervix, paracervical tissues, and parametria as well as a moderate homogeneous dose to the external iliac lymph nodes without exceeding the bladder and rectal tolerance doses (Fig. 66.22A).

Other institutions prefer higher doses of whole pelvis external irradiation (usually 40 to 45 Gy) with additional parametrial dose (with a midline 5-HVL rectangular block) to complete 50 Gy in patients with stage IB and IIA tumors and 55 to 60 Gy in patients with stage IIB, III, or IVA tumors. This is usually combined with one or two LDR intracavitary insertions for approximately 4,000 to 5,000 mgh (36 to 50 Gy to point A) to deliver a total dose of 85 to 95 Gy to point A, depending on the tumor volume and stage and age of the patient (Fig. 66.22B). We tend to reduce the total doses by 10% in women older than 70 years.

When 20 Gy is administered to the whole pelvis, for HDR brachytherapy the usual schedule is six fractions of 7 Gy or seven fractions of 6 Gy to point A. If 40 to 45 Gy is given to the whole pelvis, usually four fractions of 6 to 7 Gy to point A are administered.

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Radiation Therapy Techniques

Currently, the two main modalities of irradiation are external photon beam and brachytherapy. External irradiation is

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used to treat the whole pelvis and the parametria including the common iliac and para-aortic lymph nodes, whereas central disease (cervix, vagina, and medial parametria) is primarily irradiated with intracavitary sources. The techniques described apply, with some individualization, to most patients with cervical carcinoma (Table 66.12).


External-Beam Irradiation

External-beam pelvic irradiation is delivered before intracavitary insertions in patients with

Bulky cervical lesions or tumors beyond stage IIA to improve the geometry of the intracavitary application;
Exophytic, easily bleeding tumors;
Tumors with necrosis or infection; or
Parametrial involvement.
Volume Treated

In treatment of invasive carcinoma of the uterine cervix, it is important to deliver adequate doses of irradiation not only to the primary tumor but to the pelvic lymph nodes to maximize tumor control (146,478). Greer et al. (193) reported on intraoperative retroperitoneal measurements carried out in 100 patients at the time of radical surgery. Both common iliac bifurcations were cephalad to the lumbosacral prominence in 87% of the patients. Therefore, the superior border of the pelvic portal should be at the L4-5 interspace to include all of the external iliac and hypogastric lymph nodes. This margin must be extended to the L3-4 interspace if common iliac nodal coverage is indicated. The width of the pelvis at the level of the obturator fossae averaged 12.3 cm, and the distance between the femoral arteries at the level of the inguinal rings averaged 14.6 cm. Posterior extension of the cardinal ligaments in their attachment to the pelvic side wall was consistently posterior to the rectum and extended to the sacral hollow. The uterosacral ligaments also extended posteriorly to the sacrum. These anatomic landmarks must be kept in mind in the correct design of lateral pelvic portals.

Greer et al. (194), based on anatomic and radiographic studies, used expanded pelvic radiation fields in 38 women with stage IIB and III cancers of the cervix. The median length and width of the anteroposterior–posteroanterior fields were 20 and 17.5 cm, respectively. Lateral fields had a median width of 16.5 cm and the posterior border encompassed the entire sacral silhouette.

Bonin et al. (45), in a review of 22 patients on whom detailed anatomic mapping of the anatomy of the pelvic lymph nodes was carried out by lymphangiography, concluded that if the criteria for adequacy of standard pelvic fields as defined by the GOG were applied (anteroposterior: 1.5-cm margin on the pelvic rim; lateral field anterior edge is a vertical line anterior to the pubic symphysis and posterior border), 10 patients (45%) would have had inadequate nodal coverage in the irradiation fields. The incompletely irradiated lymph nodes were in the lowest lateral external iliac group. However, if the irradiation portals are designed as we outline in this chapter and in previous publications, almost all of the pelvic lymph nodes would be within the irradiated volumes. With the advent of IMRT to treat gynecological tumors several authors have published guidelines emphasizing imaging methods to more accurately define target volumes, including lymph nodes (50, 601) .

For stage IB disease, conventional anteroposterior and posteroanterior portals 15 by 15 cm at the surface (approximately 16.5 cm at isocenter) are sufficient. For patients with stage IIA, IIB, III, and IVA carcinoma, somewhat larger portals (18 by 15 cm at surface, 20.5 by 16.5 cm at isocenter) are required to cover all of the common iliac nodes in addition to the cephalad half of the vagina (Fig. 66.7A). A 2-cm margin lateral to the bony pelvis is adequate. If there is no vaginal extension, the lower margin of the portal is at the inferior border of the obturator foramen.

When there is vaginal involvement, the entire length of this organ should be treated down to the introitus (Fig. 66.7B). It is very important to identify the distal extension of the tumor at the time of simulation by placing a radiopaque clip or bead on the vaginal wall or inserting a small rod with a radiopaque marker in the vagina (Fig. 66.8). Use of implanted cervical markers

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to localize the vaginal apex or the cervix during simulation is more accurate than using a vaginal rod, according to Kim et al. (316); all patients showed a mean displacement of the cervical markers by the vaginal rod of 1.9 cm (range, 0.6 to 3.6 cm). The greatest displacement was cephalad (mean, 1.5 cm; range, 0.5 to 2.4 cm). Displacement was anterior in 5/8 patients, posterior in three patients, and lateral in four patients.


In patients with tumor involving the distal half of the vagina, the portals should be modified to cover the inguinal lymph nodes because of the increased probability of metastases (Fig. 66.9).

The lateral ports anterior margin is placed at the pubic symphysis; the posterior margin usually is designed to cover at least 50% of the rectum in stage IB tumors, and it should extend to the sacral hollow in patients with more advanced tumors (Fig. 66.10). The use of lateral fields allows a decrease in dose to the small bowel, but care must be taken to include all structures of interest (193, 478, 535).


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Zunino et al. (671) reviewed the appropriateness of radiation therapy box technique for cancer of the cervix in 35 sagittal MRIs and 10 lymphangiograms. An anatomic evaluation was conducted in cadavers to identify aortic bifurcation, lymph nodes, and uterus flexion. Dissection of female pelvises showed that the aortic bifurcation occurred at the inferior plate of L4 in 80% of the cadavers. The anatomic borders of the box technique used were the superior border of the anteroposterior–posteroanterior fields at the inferior edge of L4; inferior border at the inferior edge of the ischium; the lateral borders 2.5 cm outside of the bone pelvis rim; the anterior border of the lateral fields over the anterior edge of the pubic symphysis; and the posterior at the S2-3 interspace. In 50% of the patients with FIGO IB and in 67% with stage IIA disease, the posterior border of the lateral field was inadequate to encompass the PTV. In stage IIB, the posterior border was inadequate in eight patients (42%). In patients with stage IIB and IVA disease, the PTV was not encompassed. On the 35 sagittal MRIs, the placement of the posterior border of the lateral field was inadequate in 49% and the anterior border in 9% of the cases. The standard design of the lateral fields of the four-field technique based on anatomic bone references failed to encompass the PTV in a significant number of patients.

Further, Knocke et al. (329) used standard simulator planning, guided by bony landmarks for pelvic irradiation in 20 patients with primary cervical carcinoma, stages I to III, using four-field box technique. After defining the PTV with a three-dimensional (3D) planning system, the field configuration of the simulator planning was compared with a second one based on the defined PTV and evaluated regarding encompassment of the PTV by the treatment volume (International Commission on Radiation Units and Measurements [ICRU]). Planning by simulation resulted in one geographic miss, and in 10 more cases the coverage of the PTV by the treatment volume was inadequate. Three-dimensional treatment planning for pelvic irradiation of cervical carcinoma may reduce the treated volume, but further research must be done to determine whether the complication rate can be decreased as well.

Midline Shielding in Anteroposterior–Posteroanterior Portals

Depending on the institution and brachytherapy dose administered, midline shielding with rectangular or specially designed blocks are used for a portion of the external beam dose delivered with the anteroposterior–posteroanterior ports (478).

Wolfson et al. (658) compared the dose distribution in the pelvis with an individualized midline shield that conformed to the point A isodose line or a rectangular block in a retrospective review of 32 patients with invasive cervical carcinoma who underwent LDR brachytherapy. Patients were grouped as having a rectangular block (18 cases), customized block (five cases), or no block (nine cases). The point A isodose distribution from the implant was superimposed onto the whole pelvis simulation film. Approximately 72% of all cases (23/32) had tandem deviation up to 230 degrees, with a median of 50 degrees. This translated into a median percentage overdosage to point A right of 15% and left of 12.5%. Overall survival and incidence of chronic complications have not been affected by type of shielding (median follow-up of 17.7 months). Of 56 radiation facilities in the GOG surveyed concerning their use of a block, 34 (61%) responded; 88% (29/33) use a midline shield, most of them (76%) a rectangular central block that is not positioned with respect to possible tandem deviation.

Parametrial Boost

When parametrial tumor persists after 50 to 60 Gy is delivered to the parametria, an additional 10 Gy in five or six fractions may be delivered with reduced anteroposterior–posteroanterior portals (8 by 12 cm for unilateral and 12 by 12 cm portals for bilateral parametrial coverage). The central shield should be in place to protect the bladder and rectum.

Chao et al. (72) evaluated 343 patients with clinical stage IIIB cervical cancer treated with radiation therapy alone and identified 83 with clinical evidence of tumor in the uterosacral region. The average total dose, including external-beam and brachytherapy, to point A and the lateral pelvis was 80.3 to 86.5 Gy and 60.5 to 73.4 Gy, respectively. The external-beam dose to the lateral parametria was, on average, 10 Gy higher in patients with uterosacral involvement. The cumulative incidence of central/marginal failure at 5 years was significantly higher in the group of patients with uterosacral involvement (36%) compared with 21% for patients without involvement or unspecified involvement (p = 0.002). Lateral parametrial failure was similar for patients with and without uterosacral involvement (39% and 38% at 5 years, respectively; p = 0.42).

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Para-Aortic Lymph Node Irradiation

If para-aortic node metastases are present or suspected, patients are treated with 45 to 50 Gy to the para-aortic area plus a 5 to 10 Gy boost to enlarged lymph nodes through reduced lateral or rotational portals. With conventional techniques, the para-aortic lymph nodes are irradiated either with an extended field that includes both the para-aortic nodes and the pelvis or through a separate portal (Fig. 66.11) (478,492). In this case, a “gap calculation” between the pelvic and para-aortic portals must be performed to avoid overlap and excessive dose to the small intestines. The upper margin of the field is at the T12-L1 interspace and the lower margin at L5-S1. The width of the para-aortic portals (in general, 8 to 10 cm) can be determined by CT scans, MRI, lymphangiography, FDG-PET scans, or IV pyelography outlining the ureters. The spinal cord dose (T12 to L2-3) should be kept below 45 Gy by interposing a 2-cm wide 5–half-value layer (HVL) shield on the posterior portal (usually after 40-Gy tumor dose) or using lateral ports and the kidneys below 1,800 cGy. A technique using four isocentric fields weighted 2:1 anteroposterior–posteroanterior over lateral portals and 1.8-Gy fractions was described by Russell et al. (532) to deliver high-dose therapy (56 to 61 Gy), with 7/14 patients alive and free of disease from 11 to 78 months. Kodaira et al. (332) evaluated a four-field para-aortic irradiation technique with 10-MV photons (mean, 50.4 Gy) in 97 patients with cervical cancer. The 5-year cause-specific survival rate was 32.2%. Grade 1 or 2 stomach and duodenum sequelae developed in 26.8%, grade 2 sequelae of small bowel in 3.1%, and grade 2 sequelae of bone in 3.1%.

Esthappan et al. (150) described a technique using CT and FDG-PET retroperitoneal to treat the para-aortic lymph nodes (50.4 and 59.4 Gy) with IMRT (Fig. 66.12). Acceptable dose distribution of the target volumes and sparing of the stomach, liver, and colon was achieved. Sparing of the spinal cord was dependent on the number and arrangements of the beams, as was the small bowel, sparing of which was limited because of overlap with the target volume. Adjusting number of beams and prescription parameters minimally improved kidney sparing.


Beam Energies

Because of the thickness of the pelvis, with conventional irradiation high-energy photon beams (10 MV or higher) are especially suited for this treatment. They decrease the dose of radiation delivered to the peripheral normal tissues (particularly bladder and rectum) and provide a more homogeneous dose distribution in the central pelvis. With lower-energy photons (Cobalt-60 or 4- to 6-MV x-rays), higher maximum doses must be given, and more complicated field arrangements should be used to achieve the same midplane tumor dose (three-field or four-field pelvic box or rotational techniques) while minimizing the dose to the bladder and rectum and to avoid subcutaneous fibrosis (Fig. 66.13) (253). Biggs and Russell (38) noted that the presence of a metallic prosthesis when using lateral fields or a box pelvic irradiation technique may result in a dose decrease of approximately 2% for 25-MV x-rays and average increases of 2% for 10-MV x-rays and 5% for 60Co.

Allt (11) and Johns (285), in an update of a randomized study, reported better pelvic tumor control and survival and fewer complications in 65 patients with stage IIB and III cervical carcinoma treated with 23-MV photons compared with 61 treated with external irradiation with 60Co, in addition to brachytherapy in both groups. In contrast, Holcomb et al. (253) compared outcome of 195 patients with stage IIB-IVA cervical carcinoma treated with 60Co radiation therapy (group 1) and 53 treated with linear accelerators (group 2). There was no significant difference in overall survival, although there was a trend toward increasing pelvic recurrence in the 60Co group (50.8%) compared with group 2 (35.8%; p = 0.08).

Hyperfractionated or Accelerated Hyperfractionated Radiation Therapy for Locally Advanced Cervix Cancer

MacLeod et al. (391) reported on a phase II trial of 61 patients with locally advanced cervical cancer treated with accelerated hyperfractionated radiation therapy (1.25 Gy administered twice daily at least 6 hours apart to a total pelvic dose of 57.5 Gy). A boost dose was administered with either LDR brachytherapy or EBRT to a smaller volume. Thirty patients had acute toxicity that required regular medication. One patient died of acute treatment-related toxicity. The overall 5-year survival was 27%, RFS was 36%, and actuarial local tumor control was 66%. There were eight severe late complications observed in seven patients, who required surgical intervention (actuarial rate of 27%). Five patients also required total hip replacement.

Viswanathan et al. (638) reported on 30 patients with stage II or III cervical cancer randomized to receive either hyperfractionation (15 patients) or conventional fractionation (15 patients). At 5 years, two patients in the hyperfractionation group and eight patients in the conventional treatment group had recurrent tumor (p = 0.04). Delayed bowel complications (grade 2 and 3) occurred in nine women in the hyperfractionation group and two patients in the conventional group (p = 0.0006).

The Radiation Therapy Oncology Group (RTOG 88-05) conducted a phase II trial of hyperfractionation (1.2 Gy to the whole pelvis twice daily at 4- to 6-hour intervals, 5 days per week) with brachytherapy in 81 patients with locally advanced carcinoma of the cervix. Total dose to the whole pelvis was 24 to 48 Gy, followed by one or two LDR intracavitary applications to deliver 85 Gy at point A and 65 Gy to the lateral pelvic nodes. Grigsby et al. (209) updated the results and noted that external

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irradiation was completed in 71 (88%). The 5-year cumulative rates of grade 3 and 4 late effects for patients with stages IB2 or IIB tumors was 7% and at 8 years 10%, and with stage III or IVA disease, 12% at 5 years. The absolute survival was 48% at 8 years, and disease-free survival 33%, respectively. Comparison with historical control patients treated on other RTOG showed equivalent rates of pelvic tumor control, survival, and grade 3 and 4 toxicities at 3, 5, and 8 years, respectively.


Concomitant Boost

Kavanagh et al. (306) reported on 20 patients with FIGO stage III squamous-cell carcinoma of the cervix who were irradiated in a clinical trial involving a concomitant boost regimen. Patients received 45 Gy to the pelvis in 25 fractions in 5 weeks. On Monday, Wednesday, and Friday of the last 3 weeks, an additional 1.6-Gy boost was given 6 hours after the whole pelvis treatment (14.4 Gy) through lateral fields encompassing the parametria and primary tumor, for a total tumor dose of 59.4 Gy. A single LDR brachytherapy procedure was performed within 1 week after the external-beam radiation therapy to raise the point A dose to 85 to 90 Gy in 42 days. Mean total treatment time was 46 days. Results were compared with patients treated with conventional radiation therapy during the same years. The 4-year actuarial tumor control rates were 78% in the concomitant boost and 70% in the conventional irradiation group (p = not significant). Only two patients receiving concomitant boost required a treatment break because of acute toxicity, but severe late

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complications occurred in 8/20 patients. Further investigations into external-beam dose intensification should be conducted only with a more sophisticated technique than what was available during the time of the study to reduce toxicity.


Three-Dimensional or Intensity-Modulated Radiation Therapy

There is increasing experience with 3D or IMRT in cervical cancer, although results are preliminary. Portelance et al. (493) carried out IMRT as well as conventional planning with two- and four-field techniques in 10 patients. Prescription was 45 Gy in 25 fractions to the uterus and the pelvic and para-aortic lymph nodes. All IMRT plans were normalized to obtain a full coverage of the cervix with the 95% isodose curve (Fig. 66.14A). The volumes of small bowel receiving the prescribed dose (45 Gy) with IMRT technique were, with four fields, 11%; seven fields, 15%; and nine fields, 13.5% (Fig. 66.14B). These dose distributions were all significantly better than with two-field or four-field conventional techniques (p <0.05.) Ahmed et al. (7) arrived at similar conclusions in five patients with para-aortic node metastasis, and they demonstrated the feasibility of escalating the dose to 60 Gy while sparing the kidneys, spinal cord, small bowel, and bone marrow. Heron et al. (245), in a study of 10 patients, showed that with IMRT there was a reduction of 52% in the small bowel volume receiving >30 Gy and a decrease of 66% for the rectum and 36% for the bladder, compared with 3D continuous radiation therapy (CRT). D'Souza et al. (105), in 10 patients, also noted a reduction of small bowel volume (33%) with IMRT compared with four-field pelvic RT; however, small volumes of bowel received 55 to 60 Gy with the IMRT plans. A patient prone position on a “belly board” was shown to reduce volume of small bowel irradiated (4).

Brixley et al. (55) and Lujan et al. (389) also used IMRT planning to spare the bone marrow of patients with gynecological tumors. Brixey et al. (55), in 36 patients, noted no significant difference in hematologic toxicity with IMRT or conventional RT alone; however, in patients receiving chemotherapy less grade 2 white blood cell toxicity was observed with IMRT (31.2% vs. 60%, respectively).

Uncertainties in the definition of target volumes when using 3D techniques have been identified (646). Bladder-filling control and accurate definition of margins for the PTV with image-guided position verification have been advocated to achieve a better application of IMRT (227). An example of dose distribution achieved with IMRT pelvic irradiation is illustrated in Fig. 66.15.

Early results with IMRT have been published. Kavanagh et al. (307) described the outcome of a small cohort of patients with stage IIB or IVA cervical cancer with medical illness or severe tumor-related anatomic distortion that limited delivery of brachytherapy. IMRT was used to provide a simultaneous boost dose to the primary tumor at the time of external-beam treatment to a larger pelvic field given in conventional fractions. The toxicity of IMRT was acceptable, and early tumor responses were encouraging.

Guerrero et al. (214) proposed using an IMRT simultaneous integrated boost (SIB) as an alternative to conventional whole pelvis irradiation and used the linear quadratic equation to calculate equivalent uniform dose in multiple plans. For example, an SIB plan with 25 fractions of 3.1 Gy (77.5 Gy) is equivalent to 45 Gy whole pelvis with external beam and 30 Gy HDR in five fractions brachytherapy boost.

Molla et al. (415) proposed fractionated stereotactic RT as an alternative to brachytherapy to boost the dose to the vaginal and medial parametria in patients with carcinoma of the cervix or endometrium (2 × 7 Gy to PTV with 4-to 7-day intervals postoperatively or in nonoperated patients 5 × 4 Gy with 2-to 3-day intervals). None of 16 patients treated developed urinary or intestinal morbidity.

Although not as critical in older patients, it is important to keep in mind that while IMRT has dosimetric advantages over conventional RT, IMRT exposes a greater amount of normal tissues to lower irradiation levels, which has the potential to increase the incidence of radiation-induced second cancers (224), a phenomenon already described with conventional RT techniques (43).