Efficacy of pelvic intensity-modulated radiotherapy with hypofractionated simultaneous integrated boost to the prostate for intermediate-and high-risk prostate cancer

Objectives The objective of this study is to evaluate the efficacy as well as acute and late toxicities of pelvic intensitymodulated radiotherapy (IMRT) with hypofractionated simultaneous integrated boost (SIB) to the prostate for patients with intermediate-and high-risk prostate cancer. Methods A retrospective analysis was performed of 66 patients treated definitively with pelvic SIB-IMRT in a prospective fashion; all of whom also received androgen suppression. The IMRT plans were designed to deliver 70 Gy in 28 fractions (2.5 Gy/fraction) to the prostate while simultaneously delivering 50.4 Gy in 28 fractions (1.8 Gy/fraction) to the pelvic lymph nodes. Results Forty-four high-risk (GS 8-10, PSA>20 or=T2c) patients and 22 intermediate-risk (GS7, 10<PSA<20 or cT2b) patients received SIB-IMRT. The 3-year and 4-year rates of actuarial freedom from biochemical failure (FFbF) for all patients receiving SIB-IMRT were 89.5 and 83.9 %, respectively. Prostate cancer-specific survival at 3-and 5-year post RT completion was 98.2 and 90.6 %, respectively. Conclusion Pelvic IMRT utilizing a simultaneous integrated boost to the prostate appears to be a safe treatment regimen for high-and high-intermediate-risk prostate cancer patients, allowing them to be treated in an accelerated fashion without compromising biochemical control, freedom from distant metastasis, or prostate cancer-specific survival.