Outcome of postoperative radiotherapy following radical prostatectomy: a single institutional experience

Purpose: This single institutional study is aimed to observe the outcome of patients who received postoperative radiotherapy after radical prostatectomy. Materials and Methods: A total of 59 men with histologically identified prostate adenocarcinoma who had received postoperative radiation after radical prostatectomy from August 2005 to July 2011 in Seoul St. Mary's Hospital of the Catholic University of Korea, was included. They received 45-50 Gy to the pelvis and boost on the prostate bed was given up to total dose of 63-72 Gy (median, 64.8 Gy) in conventional fractionation. The proportion of patients given hormonal therapy and the pattern in which it was given were analyzed. Primary endpoint was biochemical relapse-free survival (bRFS) after radiotherapy completion. Secondary endpoint was overall survival (OS). Biochemical relapse was defined as a prostate-specific antigen level above 0.2 ng/mL. Results: After median follow-up of 53 months (range, 0 to 104 months), the 5-year bRFS of all patients was estimated 80.4%. The 5-year OS was estimated 96.6%. Patients who were given androgen deprivation therapy had a 5-year bRFS of 95.1% while the ones who were not given any had that of 40.0% (p < 0.01). However, the statistical significance in survival difference did not persist in multivariate analysis. The 3-year actuarial grade 3 chronic toxicity was 1.7% and no grade 3 acute toxicity was observed. Conclusion: The biochemical and toxicity outcome of post-radical prostatectomy radiotherapy in our institution is favorable and comparable to those of other studies.