Executive Summary of the American Radium Society Appropriate Use Criteria: Regional Nodal Irradiation for Breast Cancer.

Objectives: Recent literature has provided additional data to further individualize treatment recommendations on regional nodal irradiation (RNI) patient selection and delivery techniques, but controversies surrounding optimal RNI utilization remain, including radiation technique, modality selection, and internal mammary lymph node (IMN) inclusion. The American Radium Society (ARS) Breast Appropriate Use Criteria (AUC) Committee performed a systematic review and developed a consensus guideline to summarize recent data and provide evidence-based recommendations.

Methods: A multidisciplinary panel comprised of 15 members representing radiation oncologists, medical oncologists, and surgical oncologists specializing in the treatment of breast cancer conducted an analysis of the medical literature from January 1, 2011 to April 1, 2024. Modified Delphi methodology was used to rate the appropriateness of treatments for variants across 3 key questions.

Results: Patients with intermediate-risk breast cancer, such as limited nodal involvement or large primary tumor size, are reasonable candidates for RNI, although a subset of patients with overall favorable clinicopathologic features may be considered for treatment de-escalation. Data on the use of advanced radiation techniques for RNI were limited in scope and strength, and the panel agreed that careful patient selection is needed when using these tools. Evidence suggests that the IMN should be included when delivering RNI given the absolute benefit demonstrated in multiple randomized trials.

Conclusion: A systematic review and evidence-based summary of recommendations are provided in these consensus guidelines from the ARS Breast AUC Committee to provide current comprehensive guidance on the optimal management of non-metastatic breast cancer patients being considered for RNI.