Late Toxicity of Prostate Ultrahypofractionated Radiation Therapy Compared With Moderate Hypofractionation in a Randomized Trial

Abstract

PurposeWe report late toxicity, quality of life (QOL) and urinary symptom score with prostate cancer radiotherapy in a randomized trial comparing moderate hypofractionation (MHF) and ultrahypofrationation (UHF) Methods and MaterialsPatients with intermediate and high risk prostate cancer were randomized to either Arm 1 (70Gy/28 fractions) or Arm 2 (36.25Gy/5 weekly fractions). Late toxicity was evaluated using the Common Terminology Criteria for Adverse Events (CTCAE) and Radiation Therapy Oncology Group/Subjective, Objective, Management, Analytic (RTOG/SOMA) scales. QOL was assessed with the Expanded Prostate Inventory Composite-26 Short Form (EPIC-26) and urinary function with the International Prostate Symptom Score (IPSS). ResultsEighty participants were randomized. Two from Arm 1 withdrew, leaving 36 patients in Arm 1 and 42 in Arm 2. There were no significant differences in baseline characteristics, except for worse IPSS in Arm 2. No difference was observed in freedom from grade 3 or worse toxicity between treatments (p=0.921), with only a single grade 3 event in each arm. There was no significant difference in freedom from grade 2 or worse toxicity (p=0.280). No difference was observed in freedom from grade 2 or worse genitorurinary toxicity, with cumulative probabilities of 69.0% and 87.0% at 5-years for Arms 1 and 2, respectively (0.132). No difference was observed in freedom from grade 2 or worse gastrointestinal toxicity, with cumulative probabilities of 74.0% in Arm 1 and 80.0% in Arm 2 (p=0.430). There were no significant differences in EPIC-26 QOL between arms. ConclusionUHF, delivered weekly, is well tolerated with no significant differences in freedom from late toxicity compared to MHF.