Comparison of sentinel node mapping between radiocolloid SPECT/CT and interstitial magnetic resonance lymphography using superparamagnetic iron oxides and gadoxetate sodium in the head and neck region - A preliminary animal study

Objectives To comparatively assess which study is most preferable in sentinel node (SN) mapping of the head and neck region when radiocolloid SPECT/CT and interstitial magnetic resonance (MR) lymphography using superparamagnetic iron oxide (SPIO) and gadoxetate sodium are performed in animal models.

Methods We used BALB/c Slc-nu/nu mice. The mice were administered 0.01 mL of Tc-99m radiocolloid (phytate) of 3.7 MBq, or 0.01 mL of MRI contrast agent, ferucarbotran or gadoxetate sodium, into the submucosal tissue of the right margin of the tongue. Sequential SPECT/CT or MR images were acquired from 10-30 min up to 24 h after the injections using a NanoSPECT/CT or a 4.7-T MRI equipment.

Results The right and left submental and submandibular nodes were well visualized on SPECT/CT from 10 min to 24 h after the injection. The right and left submandibular nodes were visualized as low-signal intensity signals on T2*WI from 30 min to 24 h after the injection of ferucarbotran. However, the nodes were visualized as high-signal intensity signals on T1WI from 10 min to 80 min after the injection of gadoxetate sodium, although their intensity was gradually decreased.

Conclusions Radiocolloid SPECT/CT SN mapping was most preferable, though SPIO and gadoxetate sodium have the potential of being employed for SN detection with interstitial MR lymphography.

Research Support This study was funded by a grant from the 2009 Health, Welfare, Labor, Science Ministry Research Subsidy (2009-cancer clinical general - 016). We thank the BioView Company for its devoted cooperation in this research