Intensity-modulated radiotherapy as primary therapy for prostate cancer: Report on acute toxicity after dose escalation with simultaneous integrated boost to intraprostatic lesion

Purpose: To report on the acute toxicity of a third escalation level using intensity-modulated radiotherapy, for prostate cancer (PCa) and the acute toxicity resulting front delivery of a simultaneous integrated boost (SIB) to an intraprostatic lesion (IPL) detected on magnetic resonance imaging (MRI), with or without spectroscopy. Methods and Materials: Between January 2002 and March 2007, we treated 230 patients with intensity-modulated radio crapy to a third escalation level as primary, therapy, for prostate cancer. Ifan IPL (defined by, NIRI or NIRI plus spectroscopy) was present, a SIB was delivered to the IPL. To report on acute toxicity,, patients were seen weekly, during treatment and I and 3 months after treatment. Toxicity was scored using the Radiation Therapy, Oncology, Group toxicity, scale, supplemented by an in-house-developed scoring system. Results: The median close to the planning target volume was 78 Gy. An IPL was found in 118 patients. The median dose-to the MRI-detected IPL and MRI plus spectroscopy-detected IPL, was 81 Gy and 82 Gy, respectively. No Grade 3 or 4 acute gastrointestinal toxicity developed. Grade 2 acute gastrointestinal toxicity was present in 26 patients (11%). Grade 3 genitourinary, toxicity was present in 15 patients (7%), and 95 patients developed Grade 2 acute genitourinary, toxicity, (41%). No statistically, significant increase was found in Grade 2-3 acute gastrointestinal or genitourinary, toxicity, after a SIB to in IPL. Conclusion: The results of our study, have shown that treatment-induced acute toxicity remains low when intensity-modulated radiotherapy, to 80 Gy as primary therapy, for prostate cancer is used. In addition, a SIB to an IPL did not increase the severity or incidence of acute toxicity. (C) 2008 Elsevier Inc.