Carbon Ion Radiotherapy for Locally advanced Adenocarcinoma of the Uterine Cervix.

AbstractPurpose: To evaluate the toxicity and efficacy of carbon ion radiotherapy (CIRT) for locally advanced cervical adenocarcinoma by a phase I/II dose-escalation study.Methods and Materials: Between April 1998 and March 2006, 32 patients with cervical adenocarcinoma were treated with CIRT. Histologically, 24 patients had adenocarcinomas and 8 had adenosquamous carcinomas. Seven patients had stage IIB, 23 had stage IIIB, and 2 had stage IVA disease. The median tumor size was 6.5 cm. The treatment consisted of whole pelvic irradiation and local boost. The clinical target volume (CTV) of whole pelvic irradiation included the cervical tumor, uterus, parametrium, at least the upper half of the vagina, and pelvic lymph nodes. The dose of the whole pelvic irradiation was fixed at 36.0 gray equivalent (GyE) in 12 fractions. In local boost irradiation, the CTV was shrunk to the cervical tumor and surrounding tissues, and an additional dose of 26.4-35.2 GyE/8 fractions was delivered (total dose: 62.4-71.2 GyE). The dose to the GI tracts was limited to less than 60 GyE. The median follow-up duration for all patients was 21.5 months (range, 6-81 months).Results: No patient developed severe acute toxicity. No patient developed major late complications except for one patient with a rectovaginal fistula. Local control was obtained in 4 of the 7 patients receiving a total of 62.4-64.8 GyE, in 7 of the 9 patients receiving 68.0 GyE, and in 11 of the 13 patients receiving 71.2GyE. The 3-year overall survival rates for all patients and the 25 patients with stage IIIB or IVA disease were 66% and 60%, respectively. Conclusions: Although the number of patients was small, the results have suggested that CIRT provided favorable local tumor control and overall survival with acceptable rates of late complications in the treatment of locally advanced cervical adenocarcinoma.NIRS-CNAO Joint Symposium on Carbon Ion Radiotherap