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

## TL;DR

Image-guided brachytherapy improves cancer treatment by precisely targeting tumors and protecting nearby organs, leading to better outcomes for patients with uterine cancers.

## Contribution

This review provides updated evidence on the benefits and implementation of image-guided adaptive brachytherapy for various uterine cancers.

## Key findings

- IGABT improves local control and reduces severe side effects in locally advanced cervical cancer.
- MRI and 3D imaging enhance treatment precision in brachytherapy for uterine malignancies.
- Patient-reported outcomes and advanced imaging technologies are key areas of ongoing development in IGABT.

## Abstract

Brachytherapy is an essential part of curative treatment for cervical, endometrial, and vaginal malignancies. Over the past two decades, image-guided brachytherapy (IGABT) has transformed brachytherapy by allowing the dose to be tailored more precisely to the tumor in 3D while better protecting the surrounding organs. This has translated into improved local control and fewer severe long-term side effects in patients with locally advanced cervical cancer; similar results were seen in IGABT for endometrial and vaginal cancers. In this review, we summarize current evidence for IGABT across uterine cancers, discuss typical dose and volume concepts, and highlight patient-reported outcomes and emerging technologies such as advanced imaging and artificial intelligence. We also outline the practical challenges and opportunities for wider implementation of IGABT in diverse clinical settings.

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.