Early salvage radiotherapy for patients with PSA relapse after radical prostatectomy

Abstract

To assess the effectiveness of early salvage radiotherapy (RT) for patients with prostate-specific antigen (PSA) relapse after radical prostatectomy (RP) retrospectively. Fifty-one patients underwent salvage RT for biochemical relapse of prostate cancer initially treated with RP. All patients had persistent or rising PSA >0.20 ng/ml at some point after surgery, or three successive PSA elevations after a postoperative nadir if PSA was < or =0.20 ng/ml. Most (96%) of pre-RT PSA were less or equal to 0.50 ng/ml, and median value was 0.25 ng/ml (range, 0.05-0.90 ng/ml). Median RT dose was 60 Gy (range, 50-66 Gy). Multivariate Cox regression analysis was performed for PSA before RP and salvage RT, margin status, seminal vesicle involvement, extracapsular invasion, Gleason score, PSA doubling time (PSADT), and RT dose to identify significant predictors of biochemical outcome. Median follow-up was 36 months. The 3-year biochemical no evidence of disease rate (bNED) was 55.1%. On multivariate analysis only the following factors were significantly associated with improved bNED: PSADT >3.0 months (P = 0.008), Gleason score < or =7 (P = 0.01), and RT dose > or =60 Gy (P = 0.028). Although a total dose of 60 Gy was effective at a low pre-RT PSA levels with short follow-up, an RT dose > or =60 Gy resulted in superior biochemical outcomes even in patients with a pre-RT PSA < or =0.50 ng/ml.