Magnetic Seed Localisation for Non-Palpable Breast Lesions: A Comparison with Hooked-Wire

Introduction: Screening programs and improved imaging result in higher frequency of non-palpable breast lesions, requiring preoperative localisation. Several localisation methods have been developed, with Magseed® among the more recent techniques. This observational study registered safety, effectiveness and surgeon satisfaction of Magseed® localisation. Data were compared with hooked-wire procedure. Methods: Data regarding safety, effectiveness and surgeon satisfaction of 100 patients who underwent Magseed® localisation were prospectively collected between September 2018 and April 2019, and compared with retrospectively collected data of 91 patients who underwent hooked-wire localisation between March 2018 and September 2018. Results: In total, 103 seeds and 102 wires were included. All magnetic seeds were placed under ultrasound guidance, with a median of two days preoperative. Complication rate did not significantly differ between Magseed® and hooked-wire (2.97% vs. 2.13%; p = 1.000). 94.06% of the seeds were detected with Sentimag®, with a retrieval rate of 100%. Positive margin rate was lower for Magseed®, although not significant (4.76% vs. 10.39%; p = 0.233). Due to positive margins, 1 additional mastectomy was performed, in contrast with 3 mastectomies and 1 additional re-excision in the hooked-wire group. Surgeons scored 81% of the Magseed® procedures as ’easier than hookedwire’. Conclusion: Rate of positive margins and re-excision/mastectomy showed a tendency to be lower with Magseed® localisation compared to hooked-wire localisation. Complication rate was equal. Moreover, high surgeon satisfaction and logistical advantages designate Magseed® as preferable over hooked-wire.