Radioactive seed localization compared to wire localization in breast-conserving surgery: Initial 6-month experience

Background. Wire localization (WL) of nonpalpable breast cancers on the day of surgery is uncomfortable for patients and impacts operating room efficiency. Radioactive seed localization (RSL) before the day of surgery avoids these disadvantages. In this study we compare outcomes of our initial 6-month experience with RSL to those with WL in the preceding 6 months. Methods. Lumpectomies for invasive or intraductal cancers localized with a single 125iodine seed (January-June 2012) were compared with those using 1 wire (July- December 2011). Surgeons and radiologists did not change. Positive and close margins were defined as tumor on ink and tumor B1 mm from ink, respectively. Demographic and clinical characteristics and outcomes were compared between RSL and WL patients. Results. There were 431 RSL and 256 WL lumpectomies performed. Clinicopathologic characteristics did not differ between groups. Most seeds (90 %) were placed before the day of surgery. Positive margins were present in 7.7 % of RSL versus 5.5 % of WL patients, and 16.9 % of RSL versus 19.9 % of WL had close margins (p = 0.38). The median operative time was longer for lumpectomy and sentinel lymph node biopsy (SLNB) in the RSL group (55 vs. 48 min, p\0.0001). There was no significant difference in the volume of tissue excised between groups. Conclusions. In the first 6 months of RSL, operative scheduling was simplified, while rates of positive and close margins were similar to those seen after many years of experience with WL. Operative time was slightly longer for RSL lumpectomy and SLNB; we anticipate this will decrease with experience.