342 - Application of Polyethylene Glycol (PEG) Hydrogel in Radical Concurrent Chemoradiotherapy for Cervical Cancer to Prevent Radiation-Induced Rectal Injury: A Multicenter, Randomized, Parallel-Controlled, Prospective, Phase 3 Trial
Presenter(s)
J. Yan1, Y. Wang2, J. Qiu2, F. Zhang1, X. Zhang3, F. Wang3, W. Chen4, X. Cao5, Y. Ou5, Z. Zhang6, G. Ke7, Z. Liu8, T. Wang8, P. Xie9, Q. Guo10, W. Zhang11, Q. Jing11, and G. Li12; 1Department of Radiation Oncology, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China, 2Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China, 3Department of Gynecologic Radiation Oncology, Zhejiang Cancer Hospital, Hangzhou, Zhejiang, China, 4Department of Radiation Oncology,Fujian Cancer Hospital&Fujian Medical University Cancer Hospital, Fuzhou, China, 5Department of Radiation Oncology; State Key Laboratory of Oncology in South China; Guangdong Provincial Clinical Research Center for Cancer; Sun Yat-Sen University Cancer Center, Guangzhou, China, 6Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai, China, 7Department of Gynecologic Oncology, Fudan University Shanghai Cancer Center, Shanghai, China, 8Department of Radiation Oncology,The First Affiliated Hospital of Xi'an JiaoTong University, Xi'an, China, 9Department of Gynecologic Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China, 10Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China, 11Department of Radiation Oncology, TIanjin Medical University General Hospital, Tianjin, China, 12Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
Purpose/Objective(s): The purpose of this study was to evaluate the safety and efficacy of polyethylene glycol (PEG) hydrogel in reducing rectal radiation dose and radiation-induced rectal injury during cervical cancer brachytherapy.
Materials/Methods: In this phase 3, randomized, parallel-controlled trial (NCT 05690906) conducted across 9 medical centers in China from July 2022 to January 2025, 100 cervical cancer patients were enrolled, randomly assigned in a 1:1 ratio to the experimental group or control group. All patients were received concurrent chemoradiotherapy (CCRT), the experimental group was received a 10mL PEG hydrogel injection after external beam radiotherapy, while the control group had no injection. Followed by image-guided adaptive brachytherapy, and the doses of rectum, sigmoid, bladder, small intestine were recorded. The Common Terminology Criteria for Adverse Events (version5.0) was used to evaluate radiotherapy-induced side effects. The primary endpoint was the cumulative D2cc of rectum. Secondary endpoints included: 1) cumulative doses for rectal D0.1cc and D5cc, as well as D2cc of sigmoid, bladder, small intestine; 2) changes in the perirectal space and the volume of the hydrogel; 3) quality of life scores by QLQ-C30 and QLQ-CX24; 4) incidence of radiation-induced acute rectal injury (RARI).
Results: The study analyzed 94 patients (45 experimental, 49 control), with 6 discharged. The experimental group showed a significant increase in cervix/tumor-to-rectum distance (p<0.05) and reduced rectal doses (D2cc, D0.1cc, D5cc) compared to controls (64.23±6.58Gy vs 69.79±6.10Gy, p<0.0001; 74.67±12.22Gy vs 84.38±9.91Gy, p<0.0001; 60.23±4.96Gy vs 63.18±5.04Gy, p=0.0003), , with no significant dose changes to other organs. Hydrogel volume remained stable until 24 weeks post-radiotherapy, with 95% of patients showing significant absorption between weeks 24-36 and 5% between weeks 48-72. No significant differences were observed in acute rectal injury or quality-of-life scores (all p>0.05), except higher constipation scores in the experimental group (p=0.003). Over 1.5 years, chronic rectal injury occurred in 9.5% of the experimental group and 16.7% of controls (P>0.05), with grade =2 injury in 7.1% and 9.5%, respectively. Systemic adverse events were similar between groups.
Conclusion: Injection of medical hydrogel effectively reduces rectal dose during cervical cancer brachytherapy without increasing doses to other organs at risk and maintains acceptable safety.