Two Different Intensity-modulated Radiotherapy Strategies for Patients with High-risk Prostate Cancer

Aim: To compare toxicity profiles of two different intensity-modulated radiation therapy (IMRT) strategies in patients with high-risk prostate cancer. Patients and Methods: From May 2010 to September 2012, 43 patients with high-risk prostate cancer were treated with IMRT and concurrent hormone therapy; 23 patients were treated by conventional fractionation (IMRT/C) and 20 patients by simultaneous integrated boost (IMRT/SIB). Acute and late toxicities were compared for each group. Results: Severe acute genitourinary toxicity was recorded in 8.6% and 2% of patients in the IMRT/C and IMRT/SIB group, respectively. Genitourinary toxicity G2 was observed in 39.1% (IMRT/C group) and 25% (IMRT/SIB group) of patients. Severe acute gastrointestinal toxicity was not observed; Grade 2 acute gastrointestinal toxicity was recorded in 21.7% (IMRT/C group) and 10% (IMRT/SIB group). Grade 2 late genitourinary toxicity was observed in 26% (IMRT/C group) and 15% (IMRT/SIB group), whereas G2 late gastrointestinal toxicity in 34.5% and 30% of patients, respectively. No significant differences in incidence and severity of genitourinary and gastrointestinal toxicity were detected between the two IMRT treatment strategies. Conclusion: IMRT/SIB was well-tolerated with favorable rates of acute and late toxicity, both genitourinary and gastrointestinal. Compared to IMRT/C, IMRT/SIB maintained the same efficacy and reduced the overall treatment time.