Radiotherapy-related toxicity for localized prostate cancer: meta-analysis comparing conventional or moderately hypofractionated vs. ultrahypofractionated protocols

Abstract

Background: To compare toxicities in relation to standard radiation treatments [conventional fractionation RT (CRT) and moderate hypofractionated RT (MRT)] with ultrahypofractionated RT (URT) in the treatment of patients with localized PCa.

Methods: A searched was performed in Medline, Embase, Cochrane CENTRAL, and LILACS to January 2020 for studies comparing URT to CRT and/or MRT in relation to genitourinary (GU) and gastrointestinal (GI) toxicity in the treatment of patients with localized PCa. URT, MRT and CRT were defined as protocols delivering a daily dose of ≥5 Gy, 2.4-4.9 Gy, and <2.4 Gy per fractions regardless total dose, respectively.

Results: Eight studies with 2929 patients with localized PCa were included in the analysis. These eight studies did not find any difference between URT and MRT/CRT groups in relation to acute GU toxicity (21.0% × 23.8%, RD -0.04; 95% CI -0.13, 0.06; p = 0.46; I² = 89%) and acute GI toxicity (4.9% × 6.9%, RD -0.03; 95% CI -0.07, 0.01; p = 0.21; I² = 79%). Six studies did not find any difference between URT and MRT/CRT groups in relation to late GU toxicity (3.9% × 4.7%, RD -0.01; 95% CI -0.03, 0.00; p = 0.16; I² = 19%) and late GI toxicity (2.1% × 3.5%, RD -0.01; 95% CI -0.03, 0.00; p = 0.05; I² = 22%).

Conclusion: The present study suggests that acute GU/GI and late GU/GI toxicity are similar between URT and standard protocols. More studies with longer follow-ups directed to oncology outcomes are warranted before any recommendation on this topic.

Keywords: Rectal toxicity; Stereotactic ablative radiation therapy; Stereotactic body radiotherapy; Urinary toxicity.