Background: Mammogram-directed wire localization for nonpalpable cancer requires surgeon's time and coordination and some patient discomfort. Up to half of these nonpalpable lesions can be visualized by ultrasound. Use of intraoperative ultrasound streamlines the process of image-guided surgery.
Methods: We prospectively visualized 69 nonpalpable breast cancers between January 1998 and July 2001. Ultrasound localization was performed in the operating room immediately before definitive surgery. Breast cancers were localized using either blue dye or a guide wire.
Results: Ultrasound correctly localized all lesions at surgery. Negative margins for invasive carcinoma were found in 97% (67 of 69) of patients. Re-excisions were performed in only 6% (4 of 69) of patients. Overall negative margins were found in 90% (62 of 69) of patients. Most positive margins (71%) were due to the presence of noncalcified ductal carcinoma in situ. Mastectomy was necessary in 4% of patients, usually due to multifocal invasive carcinoma.
Conclusions: Increased familiarity with ultrasound has allowed the surgeon to localize breast cancer in the operating room, improving the process of image-guided surgery. Ultrasound localization is accurate, time efficient, technically feasible, and easier for the patient. The re-excision rate is very low and is similar to that for mammographic localization. Intraoperative ultrasound localization should be considered whenever a breast cancer needs image-guided excision.