Assessing the toxicity after moderately hypofractionated prostate and whole pelvis radiotherapy compared to conventional fractionation

Abstract

Objective: To evaluate acute and late gastrointestinal (GI) and genitourinary (GU) toxicities after moderately hypofractionated (HF) or conventionally fractionated (CF) primary whole-pelvis radiotherapy (WPRT). Methods: Primary prostate-cancer patients treated between 2009 and 2021 with either 60 Gy at 3 Gy/fraction to the prostate and 46 Gy at 2.3 Gy/fraction to the whole pelvis (HF), or 78 Gy at 2 Gy/fraction to the prostate and 50/50.4 Gy at 1.8–2 Gy/fraction to the whole pelvis (CF). Acute and late GI and GU toxicities were retrospectively assessed. Results: 106 patients received HF and 157 received CF, with a median follow-up of 12 and 57 months. Acute GI toxicity rates in the HF and CF groups were, respectively, grade 2: 46.7% vs. 37.6%, and grade 3: 0% vs. 1.3%, with no significant difference (p = 0.71). Acute GU toxicity rates were, respectively, grade 2: 20.0% vs. 31.8%, and grade 3: 2.9% vs. 0%, (p = 0.04). We compared prevalence of late GI and GU toxicities between groups after 3, 12, and 24 months and did not find any significant differences (respectively, p = 0.59, 0.22, and 0.71 for GI toxicity; p = 0.39, 0.58, and 0.90 for GU toxicity). Conclusion: Moderate HF WPRT was well tolerated during the first 2 years. Randomized trials are needed to confirm these findings.