Brachytherapy use in cervical cancer: a narrative review

For locally advanced cervical cancer, the typical radiation treatment is a combination of external beam radiation therapy (EBRT) and brachytherapy. However, variation exists in brachytherapy technique selection and implementation, stemming from differences in imaging access, operator experience, and applicator selection. As cervical brachytherapy has evolved from two-dimensional (2D) to more advanced image-guided techniques, clinicians face increasing uncertainty regarding which method of brachytherapy to use in specific clinical scenarios. This narrative review describes the evolution of intracavitary brachytherapy (ICBT), interstitial brachytherapy (ISBT), and hybrid intracavitary/interstitial brachytherapy (hybrid IC/IS-BT) techniques for cervical cancer, as well as their indications, comparative advantages, risks and benefits of each.

A search of the literature was conducted using PubMed from January 1, 2000 through December 31, 2024 to identify the findings of cervical cancer brachytherapy. Only English language publications were considered. Articles were found through the use of key terms and Boolean operators such as ("cervical cancer" AND "brachytherapy" OR "high dose rate brachytherapy") OR ("intracavitary brachytherapy" OR "interstitial brachytherapy" OR "hybrid brachytherapy").

Brachytherapy has evolved from 2D to three-dimensional planning with the advent of image-guided brachytherapy (IGBT). This modern approach encompasses techniques such as ICBT, ISBT and hybrid IC/IS-BT. Various trials, such as EMBRACE-I, indicate that magnetic resonance imaging (MRI)-guided techniques achieve superior local control and lower toxicity compared to 2D older methods. Modality selection is determined not only by tumor size and symmetry, but also by accessibility, parametrial involvement, and the ability to achieve coverage while sparing nearby organs. ICBT remains the most effective for small, centrally located tumors, while ISBT and hybrid IC/IS are preferred for bulky, asymmetric, or parametrially invasive tumors.

This review provides an overview of cervical cancer brachytherapy, including recent advances in image-guided brachytherapy-particularly with hybrid IC/IS-BT, allowing for improved tumor coverage and lowered toxicity. By framing the discussion of brachytherapy selection through specific tumor geometry, imaging findings, and resource availability, this review provides an approach for choosing the most appropriate modality. Such insights may improve future clinical practice decisions, research development, and policy efforts to ensure equitable access and training to high-quality brachytherapy.