Intraoperative radiation therapy for early-stage breast cancer.

Abstract

Intraoperative radiotherapy (IORT) offers more convenience compared to external beam radiotherapy (EBRT) following breast-conserving surgery for early-stage breast cancer. This study describes the implementation of IORT at a metropolitan academic cancer center. Demographics, tumor characteristics, margin status, adjunct EBRT, and cosmetic results were retrospectively analyzed in patients undergoing BCS with IORT. IORT consists of 20 gray delivered to the partial mastectomy cavity. From 2015 to 2020, 171 patients (65.5% African American) were included. Histologically, 104 (60.8%) patients had invasive ductal carcinoma (IDC), while 67 (39%) patients had DCIS only. Seventeen (15.9%) patients with IDC and 12 (8.6%) patients with DCIS had positive margins. There were 15 ipsilateral breast recurrences (8.8%) and three patients (20%) developed systemic disease. Twenty-five patients (14.6%) underwent adjuvant EBRT. The local recurrence-free survival at 60 months from date of IORT was 89.4% (95% CI 82.7%-93.6%). For overall survival (OS), 168 (98.2%) patients were alive at a median follow-up of 51.4 months, and three total deaths were recorded. IORT is a highly desirable and convenient alternative to EBRT for early-stage breast cancer especially for patients with poor compliance. IORT has an acceptable ipsilateral recurrence while not precluding adjunct EBRT based upon the final pathologic report.