Safety and feasibility of breast lesion localization using magnetic seeds (Magseed): a multi-centre, open-label cohort study

James R Harvey,John Murphy,Anthony J Maxwell,Miles Howe,Julie Morris,Amit Goyal,Yit Lim

doi:10.1007/s10549-018-4709-y

Abstract

PurposeWire localization has several disadvantages, notably wire migration and difficulty scheduling the procedure close to surgery. Radioactive seed localization overcomes these disadvantages, but implementation is limited due to radiation safety requirements. Magnetic seeds potentially offer the logistical benefits and transcutaneous detection equivalence of a radioactive seed, with easier implementation. This study was designed to evaluate the feasibility and safety of using magnetic seeds for breast lesion localization.MethodsA two-centre open-label cohort study to assess the feasibility and safety of magnetic seed (Magseed) localization of breast lesions. Magseeds were placed under radiological guidance into women having total mastectomy surgery. The primary outcome measure was seed migration distance. Secondary outcome measures included accuracy of placement, ease of transcutaneous detection, seed integrity and safety.ResultsTwenty-nine Magseeds were placed into the breasts of 28 patients under ultrasound guidance. There was no migration of the seeds between placement and surgery. Twenty-seven seeds were placed directly in the target lesion with the other seeds being 2 and 3 mm away. All seeds were detectable transcutaneously in all breast sizes and at all depths. There were no complications or safety issues.ConclusionsMagnetic seeds are a feasible and safe method of breast lesion localization. They can be accurately placed, demonstrate no migration in this feasibility study and are detectable in all sizes and depths of breast tissue. Now that safety and feasibility have been demonstrated, further clinical studies are required to evaluate the seed’s effectiveness in wide local excision surgery.

Highlights

Excision of impalpable breast lesions is usually directed by preoperative wire placement into or adjacent to the target lesion
Nine seeds had no tissue reaction and nine showed evidence of mild inflammatory and foreign body reaction with fibrosis. This feasibility study aimed to demonstrate that the magnetic seed (Magseed) device could be used for localization of breast cancers
The magnetic signature of the Magseed device is detected by the Sentimag probe

Summary

Introduction

Excision of impalpable breast lesions is usually directed by preoperative wire placement into or adjacent to the target lesion. Wire localization has several disadvantages, most notably, displacement of the wire, and difficulty in the surgeon discerning accurately the position of the tip of the wire intraoperatively [1]. Wire placement occurs on the day of surgery which can create problems for radiology and surgery scheduling and lead to delays in the operating theatre. It remains the default method of localization due to the limitations of other methods of localization and given the long-term data supporting its effectiveness [2]. It can be performed prior to the day of surgery and the surgeon can accurately localize the device in theatre using a hand-held gamma probe, providing major logistical advantages [3].

Objectives

Methods

Results

Conclusion