Carbon ion radiotherapy for locally advanced adenocarcinoma of the uterine cervix

The Purpose of this study was to evaluate the toxicity and efficacy of carbon ion radiotherapy (CIRT) for locally advanced cervical adenocarcinoma by phase I/II dose-escalation study. Between April 1998 and August 2008, 45 patients with cervical adenocarcinoma were treated with CIRT. Histologically, 36 patients had adenocarcinomas and 9 had adenosquamous carcinomas. Fifteen patients had stage IIB, 28 had stage IIIB, and 2 had stage IVA disease. The dose of the whole pelvic irradiation was fixed at 36.0 gray equivalent (GyE) in 12 fractions, and an additional dose of 26.4-38.4 GyE in 8 fractions was delivered to the cervical tumor (total dose: 62.4-74.4 GyE). The dose to the GI tracts was limited to less than 60 GyE. The median follow-up duration for all patients was 23 months (range, 6-93 months). 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 6 of the 9 patients receiving 68.0 GyE, in 13 of the 19 patients receiving 71.2 GyE, and in all of 7 patients receiving 74.4 GyE. The 5-year local control and overall survival rates for stage IIIB or IVA patients who received ≥68.0 GyE were 64% and 46%, respectively. 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. (author)