It would be of great advantage to us if we were able to improve the early detection of responders to salvage external beam radiotherapy (RT) after failed radical prostatectomy (RP). Early detection would allow us to make earlier treatment decisions which should provide for better results.
In an attempt to better improve our understanding of early detection, between 2002 and 2007, at a single institution, 136 consecutive men received salvage radiation treatment (RT) to a dose of 66Gy without androgen-deprivation therapy (ADT) aftera prostatectomy (surgery) for a rising prostate-specific antigen (PSA) level. PSA measurements were systematically performed before radiation therapy at the fifth week of radiotherapy, and in the follow-up at least twice a year (every 6mo).

The median follow-up was 60 months. The 5-year freedom from biochemical and clinical failure rates were 57% (95% CI: 48%-66%) and 92% (95% CI: 87%-97%), respectively. The mean PSA5 was 0.61ng/ml (range: 0-7) and the mean PSA ratio was 0.67 (0-1.7). A PSA ratio< 1 was a significant prognostic factor in multivariate analysis for both definitions of biochemical failure (P = 0.01 for both) and for clinical failure (P = 0.005).For men undergoing salvage radiotherapy, without ADT after surgery with a rising PSA level, the absence of PSA decline during radiation therapy is predictive of biochemical and clinical failure and may be used to rapidly identify poor responders.Reference: Urol Oncol. 2014 Aug 28. pii: S1078-1439(14)00277-4. doi: 10.1016/j.urolonc.2014.07.020; Gustave Roussy,PMID: 25176583Joel T Nowak, M.A., M.S.W.