Postoperative high-dose pelvic radiotherapy for N+ prostate cancer: Toxicity and matched case comparison with postoperative prostate bed-only radiotherapy

Abstract

PurposeTo report on toxicity of postoperative high-dose whole-pelvis radiotherapy (WPRT) with androgen deprivation therapy for lymph node metastasized (N1) prostate cancer (PC). To perform a matched-case analysis to compare this toxicity profile to postoperative prostate bed-only radiotherapy (PBRT). Materials and methodsForty-eight N1-PC patients were referred for WPRT and 239 node-negative patients for PBRT. Patients were matched 1:1 according to pre-treatment demographics, symptoms, treatment and tumor characteristics. Mean dose to the prostate bed was 75Gy (WPRT–PBRT) and 54Gy to the elective nodes (WPRT) in 36 or 37 fractions. End points are genito-urinary (GU) and gastro-intestinal (GI) toxicity. ResultsAfter WPRT, 35% developed grade 2 (G2) and 4% G3 acute GU toxicity. Acute GI toxicity developed in 42% (G2). Late GU toxicity developed in 36% (G2) and 7% (G3). One patient had G4 incontinence. Recuperation occurred in 59%. Late GI toxicity developed in 25% (G2) with 100% recuperation. Incidence of acute and late GI toxicity was higher following WPRT compared to PBRT (p⩽0.041). GU toxicity was similar. With WPRT mean dose to bladder and rectosigmoid were higher. ConclusionsPostoperative high-dose WPRT comes at the cost of a temporary increase in G2. GI toxicity compared to PBRT because larger volumes of rectosigmoid are irradiated.