O074 Localisation using multiple magnetic seeds in unilateral breast surgery: a report of clinical and radiological outcomes in a tertiary breast cancer centre

Abstract

Abstract Introduction Magnetic seeds (Magseeds) are becoming increasingly used as a method of localising non-palpable breast lesions. The cost effectiveness and reduced scheduling conflicts in comparison with wire localization has led to increased popularity in recent years. There's a paucity of data on outcomes when using multiple magseeds in one breast. In this study, we assess the radiological, operative and pathological outcomes of inserting multiple magseeds in the same breast. Methods A retrospective analysis of all magseed guided excisions preformed at the MMUH breast surgery department between January 2020 and December 2022. 40 patients with more than one magseed inserted unilaterally were included. Primary outcome measures were successful excision of lesion(s) and magseed retrieval. Secondary outcomes included re-excision rate and perioperative complications. Results The mean distance between magseeds was 48.3 and 42.5 mm on ML and CC views respectively. 9/40 used magseeds for bracketing while the rest used for excision of discrete lesions. Mean operative time was 56.65 minutes and 55% of the procedures were wide local excisions. There was no reported difficulties identifying magseeds intra-operatively or in the specimen mammogram. The mean specimen size is 33.42 mm while the mean size of the final lesion is 15.49 mm. Invasive ductal carcinoma was the commonest pathological outcome. The rate of positive margins was 20% and re-excision was 15%. One patient proceeded to completion mastectomy. Conclusion Multiple magseed localisation is a feasible, safe and effective method when utilized in bracketing a unifocal lesion or separate lesion excisions in unilateral breast surgery.