Wireless localisation of breast lesions with MagSeed. A radiological perspective of 300 cases

Abstract

Objectives: The purpose of this article is to review the technical and radiological aspects of MagSeed® localisation, to assess its accuracy based on post-localisation mammograms and excision specimen X-rays and to discuss the radiological experience of our institutions. Methods: Two-year data were collected retrospectively from three NHS boards from the West of Scotland. A total of 309 MagSeeds® were inserted under mammographic or ultrasonographic guidance in 300 women with unifocal, multifocal and/or bilateral breast lesions at the day of surgery or up to 30 days prior to it. Radiological review of post-localisation mammograms and intraoperative specimen X-rays as well as a review of the surgical outcomes were performed to assess the accuracy and efficacy of the method. Our experience relating to the technique’s strengths and downsides were also noted. Results: The MagSeeds® were inserted on average 7.2 days before surgery. The localisation technique was straight forward for the radiologists. In 99% of the cases, the MagSeed® was successfully deployed and 100% of the successfully localised lesions were excised at surgery. There was no difference in the accuracy of the localisation whether this was mammographically or ultrasonographically guided. On post-localisation mammograms, the MagSeed® was radiologically accurately positioned in 97.3% of the cases. No delayed MagSeed® migration was observed. On the specimen X-rays, the lesion was centrally positioned in 45.1%, eccentric within more than 1 mm from the margin in 35.7% and in 14.8% it was at the specimen’s margin. The re-excision rate was 18.3%. Conclusion: The MagSeed® is an accurate and reliable localisation method in breast conserving surgery with good surgical outcomes. Advances in knowledge: To our knowledge, the radiological aspects of MagSeed® localisation have not been widely described in peer-reviewed journals thus far.

Updates and Debate Concerning Margin Adequacy and Management following Breast-Conserving Surgery

“…Meanwhile, a distance of 2 mm from the tumor margin was considered adequate for ductal carcinoma in situ (DCIS) [13][14][15][16][17][18]. Table 2 shows the overview of the methods used in non-palpable tumors to mark and remove the area of interest in conservative breast surgery [19][20][21][22][23][24][25][26][27][28].…”

“…In the case of infra-clinical, non-palpable tumors, it is possible to mark the area of interest with a hook wire placed through the tumor or the injection of a radiotracer (radioguided occult lesion localization -ROLL) [19]. Recently, the use of handheld superparamagnetic devices, such as MagSeed or the Guiding-Marker System, have provided an accurate and reliable localization method in BCS with favorable surgical outcomes [20][21][22] (Table 2). Other alternative, non-radioactive, wire-free localization methods, developed to increase the likelihood of complete tumor removal, include intra-operative ultrasound guidance [23], the LOCalizer radio-frequency identification (RFID) system [24,25], reflector-guided localization through SAVI-SCOUT [26,27], and fluorescence detection after intralesional indocyanine green (ICG) solution injection [113] or intravenous administration was used [28] (Table 2).…”

Retrospective Cohort Study of Practical Applications of Paramagnetic Seed Localisation in Breast Carcinoma and Other Malignancies

“…In addition, it requires a same day procedure on the day of operation at the radiology department to avoid the dislocation of the wire [ 6 ]. Paramagnetic Seed Localisation (MSL) has been proven to be a safe and effective method to localise non-palpable breast lesions, while addressing several limitations of wire-guided localisation (WGL) such as the decoupling of radiology and surgery planning [ 7 , 8 , 9 , 10 , 11 , 12 ]. There are limitations to MSL, such as a limited ability to use MRI when a paramagnetic seed is implanted due to scattering on MRI, up to four centimetres [ 6 ].…”