Toxicity and outcome of pelvic IMRT for node-positive prostate cancer

Abstract

This study reports on the treatment techniques, toxicity, and outcome of pelvic intensity-modulated radiotherapy (IMRT) for lymph node-positive prostate cancer (LNPPC, T1-4, c/pN1 cM0). Pelvic IMRT to 45-50.4Gy was applied in 39cases either after previous surgery of involved lymph nodes (n = 18) or with a radiation boost to suspicious nodes (n = 21) with doses of 60-70Gy, usually combined with androgen deprivation (n = 37). The prostate and seminal vesicles received 70-74Gy. In cases of previous prostatectomy, prostatic fossa and remnants of seminal vesicles were given 66-70Gy. Treatment-related acute and late toxicity was graded according to the RTOG criteria. Acute radiation-related toxicity higher than grade2 occurred in 2patients (with the need for urinary catheter/subileus related to adhesions after surgery). Late toxicity was mild (grade 1-2) after a median follow-up of 70months. Over 50% of the patients reported no late morbidity (grade 0). PSA control and cancer-specific survival reached 67% and 97% at over 5years. Pelvic IMRT after the removal of affected nodes or with a radiation boost to clinically positive nodes led to an acceptable late toxicity (no grade 3/4 events), thus justifying further evaluation of this approach in a larger cohort.