Toxicity of hypofractionated intensity-modulated radiotherapy in patients with prostate cancer / 中华放射肿瘤学杂志

ABSTRACT

Objective To analyze the acute and late toxicities in patients with prostate cancer trea-ted with hypofractionated intensity-modulated radiotherapy (IMRT). Methods Between June 2006 and June 2008, 37 patients with prostate cancer were treated with hypofractionated IMRT. The clinical target vol-ume (CTV) was the prostate, seminal vesicles and pelvic lymph nodes in 24 patients, the prostate and semi-hal vesicles in 12, and only the tumor bed in 1. The dose per fraction was 2.3 - 2.8 Gy, with 2.7 Gy in 26 patients. The minimal dose was 62.5-75.0 Gy to the prostate and seminal vesicles, and 50 Gy to the pelvic lymph nodes. Results The median follow-up was 14 months. None of the patients experienced grade 4 a-cute gastro-intestinal (GI) toxicity. Grade 1, 2 and 3 acute GI toxicity occurred in 24.3%, 35.1% and 2.7% of the patients, respectively. The rectal V50>27% and V55>20% were highly significantly associat-ed with grade ≥1 acute GI toxicity. Grade 1,2 and 3 acute genitourinary (GU) toxicity occurred in 68%, 0% and 3% of the patients, respectively. The bladder V50> 10% was significantly associated with grade ≥1 acute GU toxicity. The incidence of late GI toxicity was low. No grade ≥3 late GI toxicity was observed. The incidence of late grade 1 and 2 GI toxicity was 24% and 5%, respectively. The rectal V65> 10% was highly significantly associated with grade ≥1 late GI toxicity. No late grade 4 GU toxicity was observed. The incidence of grade 1, 2 and 3 late GU toxicity was 49%, 11% and 3%, respectively. Grade ≥2 late GU toxicity was correlated with V40, V50 and mean dose of the bladder. Conclusions Acute and late toxicity of hypofractionated IMRT is acceptable in patients with prostate cancer.