Application of Recombinant Human Superoxide Dismutase in Radical Concurrent Chemoradiotherapy for Cervical Cancer to Prevent and Treat Radiation-induced Acute Rectal Injury: A Multicenter, Randomized, Open-label, Prospective Trial

Purpose: The purpose of this study was to evaluate the efficacy fi cacy of recombinant human superoxide dismutase (rhSOD) enemas in radiation-induced acute rectal injury (RARI) in patients with locally advanced cervical cancer. Methods and Materials: In this phase 3, randomized, open-label trial (NCT04819685) conducted across 14 medical centers in China from June 2021 to August 2023, all patients received concurrent chemoradiation therapy (CCRT). The experimental group was treated with a rhSOD enema during chemoradiation therapy, and the control group had no enema. The Common Terminology Criteria for Adverse Events (version 5.0) was used to evaluate radiation therapy-induced - induced side effects. Endoscopic appearance was assessed using the Vienna Rectoscopy Score. The primary endpoint in the acute phase was the occurrence rate and duration of grade >= 1 (>= G1) >= G1) diarrhea during CCRT. Secondary endpoints included the occurrence rate and duration of >= G2 and >= G3 diarrhea, >= G1 and >= G2 diarrhea lasting at least 3 days, and damage to the rectal mucosa due to radiation therapy measured by endoscopy. Results: Two hundred and eighty-three patients were randomly divided into the experimental (n = 141) or control group (n = 142). The mean number of >= G1 and >= G2 diarrhea days were significantly fi cantly lower in the experimental group than in the control group (3.5 and 0.8 days vs 14.8 and 4.5 days, respectively; P < .001). The incidence of >= G2 diarrhea decreased from 53.6% to 24.1% when rhSOD enemas were used. Use of antidiarrheals was lower in the experimental group (36.2% vs 55.7%, P < .001). Three patients felt intolerable or abdominal pain after rhSOD enema. RARI grades in the experimental group tended to be lower than those in the control group (P = .061). Logistic regression analysis revealed that rhSOD enema was associated with a lower occurrence rate of >= G1/2 diarrhea for at least 3 days (P < .001). Conclusions: The results of this study suggest that rhSOD enema is safe and significantly fi cantly reduces the incidence, severity, and duration of RARI, protecting the rectal mucosa. (c) 2024 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)