Accuracy of ultrasound-guided breast-conserving surgery in the determination of adequate surgical margins

One promising method for obtaining clear surgical margins during breast-conserving surgery (BCS) is the intraoperative use of ultrasonography. The goal of this study was to assess the size of the ultrasound-measured margin associated with an adequate surgical margin. The study was designed as a prospective cohort study. Patients with primary invasive breast cancer undergoing BCS were included. The ultrasound-measured surgical margins were compared with the pathological margins and tumor and patient characteristics. 147 patients were eligible for analysis. 21 (14.3%) patients had close or positive resection margins and 13 (8.8%) underwent a second operation. Small excision volume, multifocality, postmenopausal status, high grade tumor-associated intraductal component, and invasion of lymph vessels and lymph nodes were associated with increased risk of positive excision margins. In the study cohort, 882 US margins were measured and a good correlation to the pathological margins was observed. Overestimation of the US-measured margins relative to the pathological margins was increased with younger age, premenopausal status and intraductal component. The estimated positive and negative predictive values, sensitivity and specificity were 81.0%, 96.2%, 48.4% and 99.1%, respectively. We found that a sonographically estimated margin of greater than or equal to 4 mm was associated with an adequate pathological margin of greater than or equal to 1 mm in 100% of tumors that did not have a high grade intraductal component.

Intraoperative ultrasonography is a safe and feasible method to obtain clear surgical margins by BCS.