Post-prostatectomy salvage radiation therapy in prostate cancer upon identification of biochemical failure.

127 Background: Prostate Specific Antigen (PSA) values post-prostatectomy are used as an indication for salvage radiation therapy. It has been suggested that initiation of therapy at lower PSA values lead to better outcomes. This study investigates outcomes of salvage radiation therapy at specific PSA thresholds. Methods: One hundred two prostate cancer patients were treated with salvage radiotherapy at our institution with curative intent, 19 of whom had Gleason score ≤6, 52 of whom had Gleason 7, and 31 with Gleason ≥8. Median follow-up after radiotherapy was 51 months. The median PSA prior to salvage radiotherapy was 0.33 ng/mL, and the median time from prostatectomy to radiotherapy was 24.6 months. Positive margins were identified in 52 patients, and perineural invasion was positive in 83. The median dose delivered was 64.8 Gy. Results: The 5-year actuarial freedom from biochemical failure rates for NCCN low, intermediate, and high risk groups were 100%, 77%, and 62%, p=0.2449. The 5-year actuarial fr...