Magnetic marker localization via magnetic susceptometry

"Magnetic marker localization via magnetic susceptometry" is not a biological molecule or receptor but a surgical technique used to localize non-palpable breast lesions during breast-conserving surgery. It employs small implantable magnetic markers, such as Magseed (1 × 5 mm stainless steel seed), Guiding-Marker System (φ 0.28 mm × 10 mm stainless-steel hook with nylon suture), or MaMaLoc (1.5 × 3.5 mm), placed into the tumor center under ultrasound or stereotactic guidance preoperatively[1][3]. A handheld magnetic probe, like TAKUMI (cordless with Hall effect sensor), Sentimag, or others, detects the marker's magnetic susceptibility response intraoperatively, guiding precise excision without wires or radioactivity[1][3]. This method leverages the marker's magnetization in an applied field to produce detectable signals, achieving high success rates (e.g., 100% marker detection in resected specimens in feasibility studies of 87-89 patients) and low positive margin rates (6.1% requiring re-excision)[1]. It addresses limitations of wire-guided localization (discomfort, migration) and radioactive seed localization (nuclear regulations), allowing flexible scheduling as markers can remain implanted longer[1][3]. Primarily applied in breast cancer for impalpable tumors detected via screening, it supports targeted axillary dissection when combined with sentinel node biopsy[3]. Limitations include depth constraints (e.g., 21-31 mm for Guiding-Marker), metal interference, and higher costs, with FDA approval for Magseed since 2016[1][3]. Ongoing studies validate its equivalence to traditional methods in margin negativity and localization accuracy[3].

Other names

Magnetically guided localization (MGL)Magnetic marker localisationMagnetic guiding localization system