Accuracy of magnetic localisation device placement and retrieval in breast cancer patients from a single internationally accredited breast center in Johannesburg, South Africa.

Abstract

e18697 Background: A variety of techniques are used to localise breast cancers prior to breast surgery. One such technique involves the placement of a magnetic device (Magseed). the magnetic device placement data from one radiology unit in a multi-disciplinary unit consisting of 4 radiology units over a 6 month period which sees 450 newly diagnosed breast cancer patients per year and places with over 360 Magseeds in a 6 month period. The aim of the study was to conduct a review of Magseed placement and ease and efficacy of retrieval across varying depths within the breast. Methods: The device used and analyzed in this study is constructed of medical-grade stainless steel magnetized, 1x5mm in size and can be implanted long term. The seeds were placed both under ultrasound guidance and stereotactically, there were no complications at the time of placement. Post-placement ease of localization and retrieval of the Magseed Measurements of distances from the nearest perpendicular skin surface was provided by the radiologist. markers were assessed by confirmation of the presence of the Magseed(s) in the specimen through the use of the Sentimag probe and confirmation visualized by intraoperative radiology and intra-operative pathology. Results: All of the seeds were localised during surgery and retrieved without difficulties reported by surgeons. The use of intraoperative radiology confirmed retrieval of all seeds in all patients. The minimum placement depth was 8.33mm, the maximum placement depth was 87mm and the average placement depth was 47mm. The placement of the seeds were place over a range of times before surgery, from 3 days prior to surgery to up to 249 days. Localisation was 100% successful using the Sentimag probe in theatre, and the retrieval rate was 100% across the full 368 analyzed patient set. . Radiological confirmation of the Magseed placement was confirmed through the use of an intraoperative radiological Biovision machine. Our data shows that Magseeds can be placed across a wide range of breast sizes and at variable depths with no complications or difficulty experienced during intraoperative localization and retrieval of the seeds. Conclusions: The data collected, and the demographic analyzed, shows that magnetic marker placement and retrieval is possible across a wide range of depths in the breast with no complications arising in radiological placement and intraoperative localisation and retrieval. Surgeons reported ease of transcutaneous localisation. A 100% retrieval rate was reported. In all cases, clear margins were achieved with: aid from audio and visual confirmation from the Sentimag probe; intraoperative radiology and intraoperative pathology.