Superparamagnetic iron oxide (SPIO) in axillary lymph node mapping after neoadjuvant chemotheraphy

The "gold standard" for detection of sentinal lymph nodes(SLN) for breast cancer is combined blue dye and radioisotopes. After neoadjuvant chemotheraphy(NAC), SLN identification rate is low with dual tracer and the false negativity is increased in patients. The aim of this study is to compare the efficacy of superparamagnetic iron oxide (SPIO) as a tracer in SLN biopsy (SLNB) in breast cancer with standard techniques after NAC. SLNB was performed in 20 clinically node negative breast cancer patients after NAC between June 2015- December 2015 who admitted to General Surgery Department of Bezmialem Vakif University Hospital. SLN localization was performed using both magnetic technique and the standard method. Patients were injected subareolar with Tc99 the day before the surgery and the SPIO was injected subareolar intraoperatively before the blue dye. SLN was excised if it was radioactive, magnetic or painted with blue dye. Number of lymph nodes, perioperative and pathological findings were recorded. Concordance and detection rates were calculated. Totally 82 lymph nodes were excised. Finding SLN with SPIO was not inferior to radioisotope. The sensitivity of SPIO was 100%. Concordance rate of %80.49 was greatest with blue dye, but with radioisotope and SPIO it was %39 and %25.6 respectively. Magnetic tracer does not use radiation and provides both a color change (brown dye) and a handheld probe for node localization. So, it is safer and easier to use as a tracer instead of dual method, also after NAC.