The value of breast brachytherapy boost in the current era: a narrative literature review from the GEC-ESTRO breast cancer working group

Purpose

To identify patients who may benefit from an interstitial brachytherapy boost in the era of hypofractionation and widespread use of simultaneous integrated boost. Material and methods: Between 1984 and 2025, 112 articles were identified through a narrative search of the PubMed, MEDLINE, and Cochrane databases using the keywords “breast cancer”, “boost”, “interstitial brachytherapy”, and “interventional radiotherapy”. Two main areas were addressed: an update on risk factors and patient selection, and a review of boost techniques, with an emphasis on interstitial brachytherapy and comparisons with other techniques. Based on this evidence, we formulated recommendations on the role of brachytherapy boost in contemporary breast cancer (BC) treatment.