Abstract
PURPOSE: To update recommendations on patient selection criteria for accelerated partial breast irradiation (APBI) based on available clinical evidence supplemented by expert opinions. METHODS AND MATERIALS: Between 2010 and 2024, a systematic search of the PubMed, Medline, Scopus and Cochrane database identified 618 articles using the keywords "accelerated partial breast irradiation" and "APBI". This search was complemented by reviewing the reference lists of articles and manual reviewing of relevant conference abstracts and book chapters. Of these, ten prospective randomized clinical trials and seven retrospective comparative studies with a minimum median follow-up time of five years were identified. The authors reviewed the clinical evidence published on APBI, supplemented it with relevant clinical and pathological studies on breast-conserving therapy, and then formulated the recommendations presented in this manuscript. RESULTS: Based on published new clinical evidence, the GEC-ESTRO Breast Cancer Working Group recommends two categories as guidelines for selecting patients eligible for APBI: (1) low-risk group representing good candidates for APBI including patients ageing > 40 years with unifocal or multifocal within 2 cm, pTis,T1-2 (≤30 mm) pN0 or pN1mi, all histology types of breast cancer without the presence of an extensive intraductal component (EIC), without extensive lympho-vascular invasion (LVI) and with negative surgical margins for invasive tumors (≥2 mm for DCIS), (2) high-risk group, for whom APBI is considered contraindicated including patients with BRCA 1-2 mutations or ageing < 40 years; having positive margins for invasive tumor (<2 mm for DCIS), and/or multicentric or large (>30 mm), and/or triple negative tumours, and/or EIC positive, and/or extensive lympho-vascular invasion (LVI) or macrometastatic positive lymph nodes (≥pN1a) or unknown axillary status (pNx). CONCLUSIONS: Based on emerging clinical evidence, the 2010 GEC-ESTRO APBI patient selection criteria can be significantly expanded, meaning that in the future, more patients may receive APBI as a part of routine clinical practice.