Feasibility of simultaneous integrated boost IMRT (SIB-IMRT) for castration-resistant prostate cancer

We examined the feasibility of local intensity-modulated radiation therapy (IMRT) with pelvic irradiation using the simultaneous integrated boost (SIB) technique to treat patients with castration-resistant prostate cancer (CRPC) after several lines of hormonal therapy. Data from 10 consecutive patients with CRPC treated with SIB-IMRT between November 2001 and September 2009 were analyzed retrospectively. A decline in prostate-specific antigen (PSA) level was observed in all cases after SIB-IMRT. Biochemical progression-free survival at 5 years was 70% with a median follow-up of 33.5 months after SIB-IMRT. All patients completed SIB-IMRT without delay due to acute toxicity. The PSA nadir after first-line hormonal therapy, the PSA before SIB-IMRT, the PSA doubling time before SIB-IMRT and the PSA nadir after SIB-IMRT were significant factors for biochemical progression after SIB-IMRT. SIB-IMRT for patients with CRPC is feasible and has a satisfactory effect in terms of disease control.