SP6.1 - Use of Endomag (Magseed® and Magtrace®): our initial experience at Midyorks trust Free

WLE is a cornerstone in breast surgery post MILAN trail.

Breast lesions undergo wire guided localisation.

Drawbacks are scheduling, patient dissatisfaction, wire movement and discomfort, SLNB: Combined technique.

Radioactive (TcM99m) labelled nanocolloid and 2mls of diluted Patent V blue dye. NEWSTART and ALMANAC, largest UK SLNB datasets- 1% allergy rate Whereas in endomag, Magseed® Marker- Tiny Magnetic seed Less intrusive than guide-wire- flexible and precise. Can be inserted anytime before surgery. Only becomes detectable when Sentimag Probe passes over it. Magtrace® Lymphatic Tracer Non radioactive and non toxic- safer compared to blue-dye Can be injected up to 28 days prior to surgery.

Demonstrate the feasibility of Magseed® marker localisation and Magtrace® tracer injection for breast lesions and sentinel lymph nodes in our unit.

All patients who underwent breast WLE from 12/21 to 03/22 using endomag. Sample size identified 63 Total number of procedures: 64 Diagnostic excisions 8 WLE 16 WLE and SNB 39 WLE and ANC 1 Technique of magseed insertion: Stereo 41, U/S 22.

Eight patients had clear margin after second surgery One patient needed third surger Magseed not retrieved in original specimen but retrieved via intra-operative shave during same surgery: 4/ 64 (6.25%) Magseed not retrieved during surgery: 3/ 64 (4.68%) Two patients required redo surgery and one completion mastectomy.

• Magtrace Tracer Failed SNB requiring sampling: 7 / 39 (17.9%).

Endomag is safe and accurate with comparable surgical endpoints (margins) to traditional localisation.

With time (learning curve) intra-operative magseed localisation and sentinel node detection will improve.