Tolerability
SIB, toxicity, weight loss, diarrhea
All patients received a planned dose of radiotherapy and two cycles of 5-FU and MMC. IMRT was performed in 13 patients using the two-step technique, IMRT with SIB in 16, 3D-CRT in 1 and IMRT for pelvic irradiation plus a 3D-CRT boost in 1. The median total dose was 59.4 Gy (range, 55.8–59.4 Gy). Two and four patients received 57.6 Gy and 55.8 Gy, respectively, according to the dose constraints of the small intestine. Radiotherapy was interrupted in four patients because of grade 4 hematologic toxicity, and the median interruption period of the radiotherapy was 2.5 days (range, 1–6 days). The median duration of radiation treatment was 47 days (range, 43–56 days). Administration of the second cycle of chemotherapy was delayed in five patients. Five patients received reduced doses of the second cycle 5-FU and MMC, and one patient received a reduced dose of 5-FU for grade ≥ 4 hematologic toxicity, grade ≥ 3 diarrhea and severe weight loss.