Image-Guided Adaptive Brachytherapy for Uterine Cancer: A Comprehensive Review

Background/Objectives: Image-guided adaptive brachytherapy (IGABT) has transformed the standard of care for locally advanced cervical cancer (LACC), enabling volumetric target definition and dose-volume histogram (DVH)-based planning to improve pelvic tumor control while limiting severe late toxicity. Methods: A comprehensive literature search of PubMed/MEDLINE and Embase was done for articles published up to August 2024, using combinations of the following keywords and Medical Subject Heading (MeSH) terms: "cervical cancer", "endometrial cancer", "vaginal cancer", "uterine neoplasms", "brachytherapy", "high-dose-rate", "image-guided", "MRI-guided", "3D brachytherapy", "IGABT", "interstitial", "locoregional control", "toxicity", "quality of life", and "patient-reported outcomes". Results: We summarized the contemporary evidence on IGABT for cervical, endometrial, and primary or recurrent vaginal cancers, focusing on local control, survival, late morbidity, and patient-reported outcomes. We described the key target volume concepts (gross tumor volume, high- and intermediate-risk clinical target volumes), and the role of MRI-, CT-, and ultrasound-based planning with intracavitary, intracavitary-interstitial, and interstitial applicators. Conclusions: Image-guided adaptive brachytherapy has redefined the standard of care for the management of locally advanced cervical cancer. Through the integration of volumetric target concepts, DVH-based dose reporting, and advanced imaging, IGABT has enabled consistent dose escalation to the residual tumor while accounting for organ-at-risk constraints, resulting in high local control rates and reduced severe morbidity compared with historical 2D brachytherapy.