Intraoperative ultrasound-guided breast-conserving surgery: A performance analysis on the basis of novel cancer lesion classification and patients' cosmetic satisfaction

Background: Intraoperative ultrasound-guided breast-conserving surgery guarantees real-time direct visualization of tumor and resection margins. We compared surgical, oncologic, and cosmetic outcomes between intraoperative ultrasound-guided breast-conserving surgery and traditional (palpation- or wire-guided) surgery across all breast cancer lesion types. Methods: This prospective observational cohort study was conducted at the Veneto Institute of Oncology between January 2021 and October 2022. Patients with ductal carcinoma in situ, T1-2 invasive breast cancer, or post-neoadjuvant residual lesions, who were suitable for breast-conserving surgery were enrolled. A novel classification system categorized all breast cancer lesion types: solid palpable (type A); solid non-palpable (B); non-solid non-palpable (C); and post-neoadjuvant residual lesions (D). Main outcomes included involved margin rates, excision volumes, and cosmetic satisfaction. Results: In total, 206 patients were enrolled, with 103 receiving traditional (palpation- or wire-guided) surgery and 103 undergoing intraoperative ultrasound-guided breast-conserving surgery. Despite similar tumor volumes, intraoperative ultrasound-guided breast-conserving surgery resulted in significantly smaller excised volumes (P = .024), greater tumor volume to specimen volume ratios (P = .002), and lower involved margin and reoperation rates (P = .002 and P = .01, respectively), in addition to a wider closest margin width (P < .001). Stratified analyses demonstrated superior performance of intraoperative ultrasound-guided breast-conserving surgery across all breast cancer lesion types, with notable improvements observed in the most challenging ones (types C and D). One-year follow-up assessments revealed significantly greater patient satisfaction levels after intraoperative ultrasound-guided breast-conserving surgery (P < .001), with specimen volume identified as the sole significant predictor of cosmetic satisfaction (P = .001). Conclusion: Intraoperative ultrasound-guided breast-conserving surgery showed clear superiority over traditional (palpation- or wire-guided) surgery in oncologic, surgical, and cosmetic outcomes, as demonstrated by a comprehensive stratified analysis encompassing all breast cancer lesion types. Intraoperative ultrasound-guided breast-conserving surgery represents the latest and most effective paradigm for precision breast-conserving surgery.