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

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.