76 Electromagnetic Chip Bracketed vs Wire Bracketed Localization in Breast Conserving Surgery

76 Electromagnetic Chip Bracketed vs Wire Bracketed Localization in Breast Conserving Surgery

Background/Significance

Surgical navigation and localization advancements seek to improve surgical time, total tissue excised, and the need for
re-excision in breast surgery. Bracketed localization is frequently used for procedures localizing wide or multifocal breast tumors. Electromagnetic chip (EMC) localization via Smart Clip (Elucent Medical, Madison WI) is a novel approach to clip localization. This prospective evaluation compares EMC bracketed localization to conventional wire localization in bracketed breast conserving surgery (BCS).

Materials and Methods

A prospective, institutional review board–approved single-institution cohort of female patients with breast cancer undergoing EMC bracketed localization was compared with a contemporary cohort of patients with breast cancer undergoing wire bracketed BCS. Key variables included number of localizers placed, complete retrieval of localizers, additional margins taken intraoperatively, positive malignant margins, reoperation for positive margins, time of incision to radiograph, and specimen length (mm) and volume (cm³). Statistics were performed using Kruskal-Wallis test for numerical covariates and χ² test or Fisher exact test, where applicable, for categorical covariates.

Results

Seventy-four subjects were included, 31 with EMC localization vs 43 wire localization; of these, 10 EMC and 4 wire localized cases were oncoplastic reductions. All cases were performed by 8 fellowship-trained breast surgeons. The mean age was 66 years (range, 36-86). Mean tumor size was 41.2 mm for EMC vs 39.5 mm for wire cases (range, 12-90). Time from incision to specimen radiograph was shorter in EMC compared with wire cases, but not statistically significant. Cases with EMC had a fewer number of positive/close (<2 mm) ductal carcinoma in situ margins (29%), compared with 50% of the wire localized cases (P <.072). Specimen length and volume were also significantly lower with EMC vs wire localization (P = .029 and P = .019, respectively). Also, 93.5% of patients who underwent EMC localization had complete retrieval of localization device in the initial specimen (P = .172). Reoperation reexcision of tumor margins was required for only 29% of the EMC localized patients (P = .185). Use of the EMC localizer was also associated with a lower complication rate (6.5% vs. 9.3%; P = 1.00).

Conclusion

In this prospective, single-institution study, EMC localization was associated with fewer positive margins and smaller resection specimens in EMC bracketed BCS compared with wire bracketed procedures.