Surgical Perspectives on the Updated ASTRO Guideline on Partial Breast Irradiation for Breast Cancer

This is an executive summary of the most recent American Society for Radiation Oncology (ASTRO) guidelines on use of partial breast irradiation in early-stage breast cancer.In the conscientious pursuit of "right-sizing" the management of patients with early-stage breast cancer, there has been an emphasis on judicious de-escalation of therapy. A component of this paradigm shift is partial breast irradiation (PBI), an approach characterized by targeted radiation therapy (RT) to lumpectomy cavity margins rather than to the whole breast (i.e., whole breast irradiation [WBI]) after breast conservation surgery (BCS). The American Society for Radiation Oncology (ASTRO) recently completed a revision of its evidence-based guidelines for the application of PBI.¹To accomplish this, recent PBI data were reviewed by panel members, including representatives of the American Society for Radiation Oncology (ASTRO), in collaboration with the American Society of Clinical Oncology (ASCO), and the Society of Surgical Oncology (SSO), which provided representatives and peer reviewers. The guideline was approved by the ASTRO Board of Directors and endorsed by the Canadian Association of Radiation Oncology, European Society for Radiotherapy and Oncology, Royal Australian and New Zealand College of Radiologists, and the Society of Surgical Oncology.The recommendations focused on indications for PBI as an alternative to WBI and technical considerations specific to PBI. This editorial provides a summary and comments on the updated ASTRO PBI guidelines, offering insights into the implications of these findings for clinical practice and multidisciplinary decision-making while underscoring technical considerations for optimal incorporation of PBI into patient care.