Low Pre-radiotherapy Prostate-specific Antigen Level is a Significant Predictor of Treatment Success for Postoperative Radiotherapy in Patients with Prostate Cancer

Background: The optimal role of postoperative radiotherapy for patients with prostate cancer remains undefined. Materials and Methods: The medical records of 70 patients (median age: 66 years), who had received radical radiotherapy (RT) between the years 1996 and 2004 after radical prostatectomy (RP), were analyzed. Fifteen patients had received immediate adjuvant RT, while the other 55 patients had received salvage therapy. Hormonal therapy had been performed in 28 patients before RT and continued in two of them concurrently with RT. A median dose of 60 Gy was delivered to the prostate bed. Pelvic node irradiation was performed in all patients. Results: After a median follow-up period of 23 months, 21 patients had experienced biochemical failure. Actuarial 3- and 5-year biochemical relapse-free survival estimates were 67.4%. No patient had local failure, although distant metastases with biochemical failure were found in five patients. On univariate analysis, the following were significant for biochemical failures: seminar vesicle involvement, serum PSA level >1 ng/ml before RT, pathological pelvic node involvement, RT indication (adjuvant vs. salvage) and Gleason score. However, only the serum PSA level before RT was significant on multivariate analysis. Conclusion: Postoperative RT with a pre-RT PSA level <0.1 ng/ml seemed to be effective in patients with prostate cancer.