Magnetic Seed Localization (Magseed) for excision of impalpable breast lesions—The North Wales experience

Abstract

The breast surgical community has faced huge challenges due to close working relationships with radiologists who are in short supply. Breast lesion localization is moving away from the traditional wire technique, which requires an on-site radiologist to support theater scheduling. In North Wales, the introduction of Magseed for impalpable breast lesion localization has facilitated theater scheduling in the absence of same day radiology presence. We audited our first 200 Magseed cases to assess the safety and efficacy of the technique, the ease of use, and patient experience. Data were entered prospectively into an excel data base relating to Magseed cases. Data collected included demographics, pre and postoperative lesion size, histology, margin positivity, and re-excision rates. Data were submitted in real time by the radiologist performing Magseed insertion to ascertain degree of difficulty. A PROMS questionnaire was designed and sent to patients undergoing Magseed vs wire localizations. Two hundred patients underwent Magseed-guided wide local excision between May 2018 and January 2020 across 2 district general hospital sites in North Wales. Histology: 69% IDC, 20% ILC, and 11% others. Mean preoperative size 12.3 mm, postoperative size 19 mm. Re-excision rate 15%. Re-excision for DCIS was significantly more likely than for invasive disease (p < 0.0001). A significant difference was also observed between radiological mean preoperative tumor size estimate and actual histological tumor size in patients undergoing margin re-excision (p = 0.000019). Wire-guided re-excision rate was 21% in the same unit. PROMs found the procedure well tolerated by patients.Surgeons and radiologists reported Magseed to be user-friendly with minimal learning curve. Magseed use for impalpable breast lesion localization is safe, user friendly, and well tolerated by patients. It produces favorable re-excision rates when compared to published figures for wire-guided excision. The presence of DCIS and preoperative radiological size underestimation was associated with margin re-excision.

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

“…Despite the complexity in differentiating between the markers, the surgeon proceeded with successful removal of both. Some reports have demonstrated that the Magseed ® marker was not detectable if the tumor lesion was deeper than 6 cm (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22). In our study, one Magseed ® was placed at a depth of 3.6 cm.…”

“…The present study illustrates the use of the Magseed ® marker, a promising technique allowing localization of nonpalpable breast lesion. Previous reports have demonstrated safety, feasibility and clinical use of magnetic seeds (10)(11)(12)(13)(14)(15)(16)(17)(18). We report our experience using the Magseed ® magnetic marker and the Sentimag ® probe in a Belgian breast unit.…”

“…During surgery, the seed is detected using a magnetic detection probe (Sentimag ® , Sysmex, GmBH, Hamburg, Germany). Several reports have demonstrated the feasibility and safety of this technique (10)(11)(12)(13)(14)(15)(16). The aim of this study is to report the experience of 100 consecutive cases where the Magseed ® marker was used to localize non-palpable breast lesions.…”

Magseed Localisation of Non-palpable Papillary Lesions: a Pictorial Essay

“…Recent studies, including one in Hong Kong and a systematic review, have demonstrated the efficacy of Magseed in localisation of non-palpable masses. [11][12][13][14] However, the proportion of ultrasound-guided Magseed localisation of papillary or subcentimetre lesions was low. To the best of our knowledge, performance and efficacy in this group of lesions has not been established.…”

False-negative rate in the extended prospective TATTOO trial evaluating targeted axillary dissection by carbon tattooing in clinically node-positive breast cancer patients receiving neoadjuvant systemic therapy

“…There is a multitude of marking techniques with various advantages and disadvantages concerning patient comfort, detection rates, necessity of a preoperative second localization procedure, technical requirements and cost. The use of iodine seeds such as described in the RISAS trial [ 8 ] is hindered by legislation regarding radioactive compounds in several countries, magnetic seeds hamper the use of magnetic resonance imaging during PST [ 9 ], and metal clips, necessitating a second pre- or intraoperative localization procedure, had a low detection rate in prospective feasibility trials [ 10 , 11 ]. Tattooing lymph node metastases with purified carbon dye is relatively simple and low-cost (36 Euro per procedure), and has been reported to render high detection rates [ 12 ].…”