Extended-field radiotherapy and high-dose-rate brachytherapy in carcinoma of the uterine cervix: Clinical experience with and without concomitant chemotherapy

BACKGROUND. It has long been recognized that many patients with locally advanced carcinoma of the cervix harbor occult paraaortic metastases. A randomized study demonstrated that elective paraaortic irradiation improved survival and reduced distant metastases. More recently, concomitant chemotherapy with pelvic irradiation has improved survival among patients with locally advanced carcinoma of the cervix. This has led to a reexamination of the role of extended-field irradiation. An important issue is the toxicity of concomitant chemotherapy and extended-field radiotherapy. The authors report a retrospective analysis of their experience with extended-field radiotherapy and high-dose-rate brachytherapy with or without concomitant chemotherapy. METHODS. The authors treated 54 women with biopsy-confirmed carcinoma of the cervix using extended-field radiotherapy and high-dose-rate brachytherapy with or without concomitant chemotherapy. The histology was squamous cell carcinoma in 49 patients (91%) and nonsquamous cell carcinoma in 5 patients (9%). The median size of the primary tumor was 7 cm (range, 3-10 cm). Each patient received 45 grays (Gy) of external beam radiotherapy to the pelvis and the paraaortic region, followed by a parametrial boost (9 Gy) in the patients with disease extension to the parametrium or the pelvic side wall(s). Each patient also underwent two applications of high-dose-rate brachytherapy, 1 week apart. The median dose delivered to Point A from each application was 9 Gy. Forty-four of the 54 patients (81%) received concomitant chemotherapy (cisplatin, 20 mg/m²/day for 5 days) during the first and the fourth weeks of external beam radiotherapy, and once after the second high-dose rate application. Chemotherapy was not assigned randomly. RESULTS. One of the 10 patients (10%) treated without chemotherapy experienced acute toxicity, whereas 41 of 44 patients (93%) who received chemotherapy suffered from acute toxicity, including hematologic toxicity, gastrointestinal toxicity, and deep venous thrombosis. During a median follow-up period of 28 months (range, 12-70 months), 6 of the 54 patients have died (11%). The actuarial rate of local control at 3 years is 100% among the patients treated without chemotherapy, compared with 85% among those receiving chemotherapy. No one failed in the paraaortic region. The actuarial rates of freedom from distant metastases are 90% and 95% among the patients treated without and with chemotherapy, respectively. The actuarial incidence of late toxicity is 10% among the patients treated without chemotherapy and 6% among those receiving chemotherapy. CONCLUSIONS. The regimen of extended-field radiotherapy with concomitant cisplatin and high-dose-rate brachytherapy produced substantial acute toxicity, but its long-term toxicity is low and the preliminary tumor control excellent, albeit with limited follow-up. Only prospective, randomized trials can evaluate whether these results are truly better than those of pelvic radiotherapy with concomitant chemotherapy, or those of other regimens of extended-field radiotherapy with concomitant chemotherapy.