Dose-effect relationship in external beam radiotherapy combined with brachytherapy for cervical cancer: A systematic review

Abstract

Purpose: External beam radiotherapy with concurrent chemotherapy combined with brachytherapy has been described as the first treatment choice for locally advanced cervical cancer. This study aimed to systematically review the dose-effect relationship (DER) of target volumes and organs at risk (OARs) in external beam radiotherapy combined with brachytherapy for cervical cancer. Material and methods: Studies reporting DER in radical radiotherapy for cervical cancer were determined by searching PubMed, Web of Science, and Cochrane Library databases till Jan 20, 2023. Dose parameters of DER, endpoint of tumor control or type and grade of side effects of OARs as well as prediction results were analyzed from included studies. Coordinates of DER curves from the included studies were extracted and DER curves were reconstructed in the same coordinate system for comparison. Results: Thirty studies, including eleven dose-response relationships for clinical end-points, and nineteen dose-toxicity relationships for OARs were evaluated in systematic review. The most common dose-response relationship between the same dose parameter and the same clinical end-point was HR-CTV D90 vs. local tumor control, while it was D2cc of rectum versus rectal grade 2-4 side effects for dose-toxicity relationship. Conclusions: In the radical radiotherapy of cervical cancer, there were significant DERs for target volumes and OARs. Considering the interference of these factors, DERs in sub-group patients would provide precise and individualized dose constraints of radiotherapy for cervical cancer in the future.