Salvage radiotherapy for biochemical recurrence after radical prostatectomy: experience of a single center

Abstract

Background: The purpose of this study was to report the outcomes and prognostic factors of patients who underwent salvage radiotherapy (SRT) for biochemical recurrence (BCR) following radical prostatectomy (RP) at a single center. Methods: We retrospectively reviewed 48 patients who underwent SRT for BCR after RP between January 2004 and December 2012. The Kaplan-Meier method and Cox proportional hazard regression models were used to evaluate the BCR-free survivals and the prognostic factors for BCR after SRT. Results: After a median follow-up of 68.7 months (range, 34.0–143.3 months). The BCR-free survival rates at 3 and 5 years for the 48 patients after SRT were 72.9% and 68.4%, respectively. Multivariate analysis showed that pre-RT PSA (prostate specific antigen) level >0.5 ng/mL, Gleason score at RP ≥8, and seminal vesicle invasion were significantly predictive of PSA relapse after SRT (HR: 23.29, 7.92, and 21.73). The BCR-free rate at 5 years in the pre-RT PSA level ≤0.5 and >0.5 ng/mL group was 83.4% and 52.2% (P=0.007), respectively. No grade 3 or worse acute adverse events were noted. Conclusions: SRT was an effective treatment for BCR following RP with tolerable toxicities. Lower pre-RT PSA value, low Gleason score, and non-seminal vesicle invasion were significant predictors of favorable biochemical outcomes. Our results supported the current recommendations that SRT should be initiated before PSA reaches 0.5 ng/mL.