RADIOTHERAPY OPTIONS FOR LOCALIZED PROSTATE-CANCER BASED UPON PRETREATMENT SERUM PROSTATE-SPECIFIC ANTIGEN LEVELS AND BIOCHEMICAL CONTROL -A COMPREHENSIVE REVIEW OF THE LITERATURE

Purpose: To review all the available radiotherapy (RT) literature on l ocalized prostate cancer treatment where serum prostate-specific antig en (PSA) levels were used to both stratify patients and evaluate outco me and determine if any conclusions can be reached regarding an optima l radiotherapeutic management for this disease. Methods and Materials: A MEDLINE search was conducted to obtain all articles in English on p rostate cancer treatment employing RT from 1986-1997. Studies were con sidered eligible for review only if they met all the following criteri a: 1) pretreatment PSA values were recorded and grouped for subsequent evaluation, 2) posttreatment PSA values were continuously monitored, 3) definitions of biochemical control were stated, and 4) the median f ollow-up was given. Results: Of the 246 articles identified, only 20 m et the inclusion criteria; 3 using conformal external beam RT, 8 using conventional external beam RT, and 8 using interstitial brachytherapy (4 using a permanent implant alone, 3 combining external beam RT with a permanent implant, and 1 combining a conformal temporary interstiti al implant boost with external beam RT). No studies using neutrons (wi th or without external beam RT) or androgen deprivation (combined with external beam RT) were identified where patients were stratified by p retreatment PSA levels. Results for all therapies were extremely varia ble with the 3-5-year rates of biochemical control for patients with p retreatment PSA levels less than or equal to 4 ng/ml ranging from 48 t o 100%, for PSA levels >4 and less than or equal to 10 ng/ml ranging f rom 44 to 90%, for PSA levels >10 and less than or equal to 20 ng/ml r anging from 27 to 89%, and for PSA levels >20 ranging from 14 to 89%. The median Gleason score, T-stage, definition of biochemical control, and follow-up were substantially different from series to series. No R T option consistently produced superior results. Conclusions: When dat a are reviewed from studies using serum PSA levels to stratify patient s and to evaluate treatment outcome, no consistently superior RT techn ique was identified. These data suggest that standard definitions of d isease stage (combining clinical, pathologic, and biochemical criteria ) and a common definition of biochemical cure (as developed by the Ame rican Society for Therapeutic Radiology and Oncology Consensus Panel) need to be adopted to evaluate treatment efficacy and advise patients on the most appropriate radiotherapeutic option for their disease. (C) 1998 Elsevier Science Inc.