Clinical Utility of Surgeon-Performed Intraoperative Ultrasonography-Guided Wire Localization for Nonpalpable Breast Cancer: A Retrospective Cohort Study

Purpose: Accurate localization of nonpalpable breast cancer is essential for successful breast-conserving surgery (BCS). This study compared the surgical outcomes and precision between intraoperative ultrasound-guided wire localization surgery (IUWLS) and preoperative wire localization (PWL). Methods: The medical records of 685 consecutive patients with nonpalpable breast cancer who underwent BCS using IUWLS or PWL between January 2015 and December 2022 at Chungbuk National University Hospital were retrospectively analyzed. The surgical outcomes, including the operation time, positive surgical margin rate, re-excision rate, and conversion rate, were compared. The surgical precision was assessed using the median total resection volume (TRV), median optimal resection volume (ORV), and the calculated resection ratio (CRR). Results: No significant differences were observed between the IUWLS group (n = 424) and the PWL group (n = 261) in positive margin status, re-excision rate, conversion to total mastectomy, permanent margin positivity, or reoperation rate. In contrast, IUWLS was associated with a significantly shorter procedure time and a lower total resection volume (TRV) than PWL. The median (range) maximum tumor-free margin distance was significantly smaller in the IUWLS group [7 mm (5-12) vs. 13 mm (9-20), P = .002], as was the median (range) calculated resection ratio (CRR) [1.37 (0.87-9.38) vs. 4.65 (1.63-21.04), P = .01]. Conclusion: IUWLS was associated with smaller excision volumes and reduced maximum tumor-free margin distances, suggesting improved preservation of healthy breast tissue. These findings suggest that IUWLS may serve as an effective alternative to PWL, offering reduced patient discomfort related to preoperative procedures while maintaining oncologic safety.