Postprostatectomy External Beam Irradiation

Background: A significant proportion of patients will be found to have extracapsular disease and/or detectable prostate specific antigen (PSA) values after radical prostatectomy. The role of postoperative radiotherapy to the prostatic tumor bed remains controversial. Methods: Ninety patients were treated at the Joint Center for Radiation Therapy after radical prostatectomy. The medium dose to prostatic fossa was 64.0 Gy. Medium follow-up was 28.9 months (from time of prostatectomy). Failure after radiotherapy is defined as a persistently detectable PSA level or the development of a detectable PSA level after radiotherapy. None of the patients received androgen ablative therapy until documented postradiotherapy failure. Presurgical PSA levels, Gleason score, pathological findings at surgery, and preradiotherapy PSA levels were analyzed as predictors of PSA failure. Results: A presurgical PSA of >20.0 ng/ml is associated with PSA failure after radiotherapy (p = 0.0239). Preoperative Gleason score, PSA at time of radiotherapy or pathological findings at surgery do not predict for subsequent PSA failure. Conclusion: Postprostatectomy radiotherapy to the prostatic fossa is unlikely to provide long-term PSA-defined, disease-free survival for patients who undergo prostatectomy with a presurgical PSA of >20 ng/ml. Regardless of findings at surgery, these patients have a high rate of developing PSA failure.