Purpose: The aim of this study is to describe our initial experience using magnetic seeds (Magseed^®) to guide breast-conserving surgery in non-palpable breast lesions and compare the use of magnetic seed with wires to guide breast-conserving surgery in terms of clinical and pathological characteristics. Methods: We performed a retrospective study including all breast-conserving surgeries for non-palpable breast lesions under 16 mm from June 2018 to May 2021. We compared breast-conserving surgeries guided with magnetic seeds (Magseed^®) to those guided with wires, analyzing tumor and patient characteristics, surgical time, and pathological results of the surgical specimens. Results: Data from 225 cases were collected, including 149 cases guided by magnetic seeds and 76 cases guided by wires. The breast lesion was localized in every case. Both cohorts were similar regarding clinical and pathological characteristics. We found significant statistical differences (p < 0.02) in terms of the median volume (cm³) of the excised specimen, which was lower (29.3%) in the magnetic seed group compared with the wire group (32.5 [20.5–60.0]/46.0 [20.3–118.7]). We did not find significant differences regarding surgical time (min) or the affected or close margins. Conclusion: In our experience, the use of magnetic seed (Magseed^®) is a feasible option to guide breast-conserving surgery of non-palpable lesions and enabled us to resect less breast tissue.

Background: In recent years, there has been an increase in breast surgery for nonpalpable lesions. Traditionally, wires have been used to guide the resection of nonpalpable breast tumors. Recently, several devices have been commercialized as alternatives to classical wires, such as magnetic seeds (Magseed®). The aim of this study is to describe our initial experience using magnetic seeds (Magseed®) to guide breast-conserving surgery in nonpalpable breast lesions and compare the use of magnetic seed with wires to guide breast-conserving surgery, in terms of clinical and pathological characteristics. Methods: We performed a retrospective study including all breast-conserving surgeries for nonpalpable breast lesions <16 mm, from June 2018 to May 2021. We compared breast-conserving surgeries guided with magnetic seeds to those guided with wires, analyzing: tumor, and patient characteristics, surgical time, and pathological results of the surgical specimens. Results: Data from 225 cases was collected, 149 magnetic seeds and 76 wires. The breast lesion was localized in every case. Both cohorts were similar regarding clinical and pathological characteristics. We found significant statistical differences (p <0.02) in terms of the median volume (cm3) of the excised specimen, which was lower (29.3%) in the magnetic seed group compared with the wire group (32.5 [20.5-60.0] / 46.0 [20.3-118.7]). We did not find significant differences regarding surgical time (min), and affected or close margins. Conclusion: In our experience, the use of magnetic seed (Magseed®) is a feasible option to guide breast-conserving surgery of non-palpable lesions and enable us to resect less breast tissue.