Clinical experience of the Magseed magnetic marker to localize non-palpable breast lesions: a cohort study of 100 consecutive cases.

Background: The aim of this study was to report on a cohort of 100 patients where the Magseed paramagnetic marker was used to localize non-palpable breast lesions.

Methods: Data were collected from a cohort of 100 patients with non-palpable breast lesions, who underwent localization using the Magseed marker. This marker consists of a paramagnetic seed that can be seen on mammography or ultrasound and intraoperatively detected with the use of the Sentimag probe. The data were collected over a period of 23 months (May 2019 to April 2021).

Results: All 111 seeds were successfully placed in the breasts of 100 patients under ultrasound or via stereotactic guidance. Eighty-nine seeds were inserted in single lesions or small microcalcification clusters in a single breast, 12 seeds were deployed to a bracket microcalcification clusters and 10 to help localize two tumors within the same breast. Most Magseed markers (88.3%) were placed in the center of the lesion (≤1 mm). The re-excision rate was 5%. All Magseed markers were successfully retrieved and no surgical complications were observed.

Conclusions: This study reports our experience in a Belgian breast unit using the Magseed magnetic marker and it highlights the many advantages of the Magseed marker system. With this system, we successfully identified subclinical breast lesions and extended microcalcification clusters, targeting multiple sites within the same breast.