Initial report of the genitourinary and gastrointestinal toxicity of post-prostatectomy proton therapy for prostate cancer patients undergoing adjuvant or salvage radiotherapy

Abstract

Purpose: To report acute and late genitourinary (GU) and gastrointestinal (GI) toxicities associated with post-prostatectomy proton therapy (PT). Methods: The first 100 consecutive patients from 2010 to 2016 were retrospectively assessed. Baseline characteristics, prospectively graded CTCAE v4.0 toxicities, and patient-reported outcomes were reported. Late outcomes were reported for 79 patients with 3 months minimum follow up. Toxicity-free survival Kaplan-Meier curves were estimated. Logistic regression assessed associations between toxicities and clinical and treatment characteristics (p <0.05). For GI, on multivariate analysis, baseline bowel function (p =.033) associated with acute grade 1 toxicity. Rectal minimum and median dose, V10, and V20, and anterior rectal wall median dose and V10 through V65 associated with acute grade 1 GI toxicity (Ps