Results of Definitive Radiotherapy in the Treatment of Prostate Cancer / 대한비뇨기과학회지

ABSTRACT

PURPOSE: To evaluate the results of radiotherapy for the treatment of prostate cancer, we retrospectively analyzed the biochemical recurrence and morbidity after radiotherapy. MATERIALS AND METHODS: Between August 1994 and July 2002, 59 patients with prostate cancer received definitive radiotherapy. Their median age was 69 years. Of the treated patients 64.4% had T1-2 tumor, 66.1% had a Gleason score of 7 or greater, 50.9% had presenting initial prostate-specific antigen (PSA) values of 20ng/ml or greater. Conventional external radiotherapy was administered to 40 patients (67.8%), using the four-field box technique and 3-dimensional conformal radiotherapy (3D-CRT) to 19 patients (32.2%). The pelvic lymph nodes were irradiated in 23 patients (39.0%). The median radiation dose to the prostate was 66Gy (range 64.0-70.4Gy). A PSA relapse was defined according to the American Society for Therapeutic Radiology and Oncology (ASTRO) consensus criteria. Rectal and bladder morbidities were graded using the criteria of the Radiation Therapy Oncology Group. RESULTS: The 5-year estimates of overall survival and the freedom from PSA recurrence were 87.6 and 58.3%, respectively. A PSA recurrence developed in 22 patients (37.3%). A PSA recurrence was significantly associated with the primary tumor stage and post-radiotherapy PSA nadir value. Prognostic groups and the post-radiotherapy PSA nadir value emerged as independent indicators of a PSA recurrence-free survival. The rates of grades 1-2 rectum and bladder late morbidity were 18.6 and 8.5%, respectively. Most of the complicated patients experienced grade 1-2 morbidities. CONCLUSIONS: Prognostic groups and the post-radiotherapy PSA nadir value were useful prognostic factors for predicting the prognosis after radiotherapy. Further prospective studies are needed to spare more normal tissues, yield lower PSA recurrence and result in less treatment morbidity with 3D-CRT and intensity modulated radiotherapy.