Prostate-specific antigen (PSA) and radiotherapy in locally confined prostate cancer

Background: During the last years, prostate-specific antigen (PSA) has been established as the most important tumor marker for prostate cancer. The ai m of our study was to evaluate the response of PSA during and after radioth erapy of prostate cancer. Patients and Methods. From 1/95 to 6/97, 26; pati ents were irradiated for locally confined prostate cancer (11/26 patients p rimarily and 15/26 patients after radical prostatectomy). Radiation therapy was carried out with a linear accelerator with a total dose of 60 Gy to th e prostate tied. PSA values were measured immediately before, weekly during radiation therapy and every three months after in the usual follow-up patt ern. Results: During radiotherapy, median PSA values fell and continued to fall after radiotherapy. The median PSA half-life was reached 3 months afte r irradiation, the PSA nadir after 15 months. 5 patients with increasing PS A levels relapsed. Discussion: During and after radiotherapy PSA kinetics a re low with a median half-life of 3 months in our patient population. Risin g PSA profile indicates progression of tumor.