UPDATE ON THE TREATMENT OF PROSTATE-CANCER WITH EXTERNAL-BEAM IRRADIATION

BACKGROUND. We review the recent changes in the radiotherapeutic manag ement of clinically localized prostate cancer, including the implement ation of three-dimensional (3-D) conformal radiation therapy (3DCRT), biochemical disease-free survival (bNED control) using conventional an d 3DCRT techniques, and the morbidity of these treatment strategies. M ETHODS. The components of 3DCRT are discussed, including patient immob ilization, 3-D treatment planning, multileaf collimation, and electron ic portal imaging. bNED control rates from institutions using conventi onal and 3DCRT techniques are compared. The gastrointestinal (GI) and genitourinary (GU) morbidity from prospective trials using conventiona l doses of radiation are compared to data from 3DCRT series, bNED cont rol rates stratified by pretreatment prostate-specific antigen (PSA) a re compared between surgical and radiation series. RESULTS. bNED contr ol rates (3-5 years) for patients treated with conventional and 3DCRT techniques ranged from 44-70% and 30-72% with pretreatment PSA levels 4-10 and 10-20, respectively. Although direct comparisons are difficul t between treatment modalities, no difference in bNED control stratifi ed by pretreatment PSA was observed between surgical and radiation pat ients. CONCLUSIONS. Patients with clinically localized prostate cancer treated with 3DCRT demonstrate durable bNED control at 5 years. Confo rmal radiation techniques, multileaf collimation, electronic portal im aging, and patient immobilization have reduced acute and chronic GI an d GU morbidity while allowing safe dose escalation in an effort to fur ther improve local control and overall survival. (C) 1998 Wiley-Liss, Inc.