Abstract : Purpose: : To report acute and late toxicity in prostate cancer patients treated by high-dose intensity-modulated radiation therapy (IMRT) with daily image-guidance. Patients and Methods: : From 06/2004-03/2008, 102 men were treated with 80 Gy IMRT with daily image-guidance. The risk groups were as follows: low, intermediate, and high risk in 21%, 27%, and 52% of patients, respectively. Hormone therapy was given to 65% of patients. Toxicity was scored according to the CTC scale version 3.0. Results: : Median age was 69 years and median follow-up was 39 months (range, 16-61 months). Acute and late grade 2 gastrointestinal (GI) toxicity occurred in 2% and 5% of patients, respectively, while acute and late grade 3 GI toxicity was absent. Grade 2 and 3 pretreatment genitourinary (GU) morbidity (PGUM) were 15% and 2%, respectively. Acute grade 2 and 3 GU toxicity were 43% and 5% and late grade 2 and 3 GU toxicity were 21% and 1%, respectively. After multiple Cox regression analysis, PGUM was an independent predictor of decreased late ≥ grade 2 GU toxicity-free survival (hazard ratio = 9.4 (95% confidence interval: 4.1, 22.0), p < 0.001). At the end of follow-up, the incidence of late grade 2 and 3 GU toxicity decreased to 7% and 1%, respectively. Conclusion: : GI toxicity rates after IMRT with daily image-guidance were excellent. GU toxicity rates were acceptable and strongly related to PGU
