Prospective assessment of gastrointestinal and genitourinary toxicity of salvage radiotherapy for patients with prostate-specific antigen relapse or local recurrence after radical prostatectomy.

Abstract

To assess the acute and late gastrointestinal (GI) and genitourinary (GU) toxicity of salvage radiotherapy (RT). A total of 75 patients with prostate-specific antigen relapse or clinically isolated local recurrence after radical prostatectomy were accrued between 1998 and 2002 for a Phase II study to evaluate the efficacy of salvage RT plus 2-year androgen suppression. Acute and late GI and GU toxicity was prospectively assessed using the National Cancer Institute Expanded Common Toxicity Criteria Version 2. For acute toxicity, prevalence was examined. For late toxicity, cumulative incidences of Grade 2 or higher and Grade 3 toxicity were calculated. Median age was 67 years at the time of salvage RT. Median time from radical prostatectomy to RT was 36.2 months. Median follow-up was 45.1 months. Seventy-five patients were available for acute toxicity analysis, and 72 for late toxicity. Twelve percent and 40% had preexisting GI and GU dysfunction before RT, respectively. Sixty-eight percent, 21%, and 5% experienced Grade 1, 2, and 3 acute GI or GU toxicity, respectively. Cumulative incidences of Grade 2 or higher late GI and GU toxicity at 36 months were 8.7% and 22.6%, and Grade 3 late GI and GU toxicity, 1.6% and 2.8%, respectively. None had Grade 4 late toxicity. The severity of acute GU toxicity (Grade < 2 vs. >/= 2) was a significant predictor factor for Grade 2 or higher late GU toxicity after adjusting for preexisting GU dysfunction. Salvage RT generally was well tolerated. Grade 3 or higher late GI or GU toxicity was uncommon.