The Central-European SentiMag study: sentinel lymph node biopsy with superparamagnetic iron oxide (SPIO) vs. radioisotope.

Sentinel lymph node biopsy (SLNB) is the standard surgical procedure for the axilla in early node-negative breast cancer. To date, the "gold standard" to localize the sentinel lymph node (SLN) is the radiotracer (99m)Tc with or without blue dye. The aim of this study was to evaluate potential equivalency of the new SentiMag(®) technique in comparison to the "gold standard". Within this prospective, multicentric and multinational non-inferiority study including 150 patients (99m)Tc was compared with the magnetic technique, using superparamagnetic iron oxide particles (SPIOs, Sienna+(®)) for localization of SLNs. The results showed a detection rate per patient of 97.3% (146/150) for (99m)Tc vs. 98.0% (147/150) for Sienna+(®) with a similar average number of removed SLNs per patient and a higher per patient malignancy detection rate for the SPIO tracer. We obtained convincing results that magnetic SLNB can be performed easily, safely and equivalently well in comparison to the radiotracer method.