Delivery of Adjuvant Radiation in 5 Days or Less After Lumpectomy for Breast Cancer: A Systematic Review

Purpose: Recent data have been published supporting the application of ultrashort radiation therapy (RT) regimens for women with early stage breast cancer after breast conserving surgery. What has remained controversial is whether and how to apply accelerated whole breast irradiation (AWBI) or accelerated partial breast irradiation (APBI) approaches in these patients, as well as the consideration of intraoperative RT (IORT). Methods and Materials: We performed a systematic review of the literature searching for randomized and prospective data published evaluating ultrashort RT delivered in 5 days or less with APBI, AWBI, or IORT. Results: We identified 2 randomized studies evaluating AWBI (n = 5,011 patients) with 5 to 10 year follow-up, which supported the use of ultrashort course AWBI compared with hypofractionated whole breast irradiation (WBI). We identified 7 randomized trials evaluating APBI (compared with WBI) in 5 days or less (n = 8528) with numerous (n = 55) prospective studies as well, with the data supporting short course APBI. Finally, we identified 2 randomized trials evaluating IORT; however, both trials demonstrated elevated rates of recurrence with IORT compared with WBI. Conclusions: The current body of data available for ultrashort adjuvant RT regimens delivered in 5 days or less after breast conserving surgery overwhelmingly support their utilization. Although data for both exist, APBI regimens have, by far, greater numbers of patients and longer follow-up compared with AWBI. Also, given increased rates of recurrence seen with IORT with long-term follow-up, this should not be considered a standard approach at this time. (C) 2021 Elsevier Inc. All rights reserved.