Improving the therapeutic ratio of external beam irradiation for carcinoma of the prostate

From 1975 to 1983, 240 patients with carcinoma of the prostate, Stages A₂ to C, were treated with whole pelvic radiation followed by a 2-week rest and then a reduced field of radiation. The reduced prostatic field was evaluated for adequacy of tumor coverage by CT scan or ultrasound. The local regional control rate was 94%, with a 5-year actuarial survival for all stages of 72%. Severe complications occurred in 3% of patients and moderate complications in 13%. Two major factors that were identified as contributing to the risk of complications included previous or subsequent surgical intervention. Our technique of external beam radiotherapy resulted in a favorable therapeutic ratio, that is, excellent local-regional control with minimal morbidity.