Feasibility of ICG fluorescence-guided sentinel node biopsy in animal models using the HyperEye Medical System.

BACKGROUND: The sentinel lymph node (SLN) concept is accepted for several types of cancers. Current methods for sentinel node detection involve radioisotopes and blue dye. They have shown good results, but some drawbacks remain. Indocyanine green (ICG) fluorescence using the HyperEye Medical System (HEMS) was evaluated as a new method. METHODS: This was a prospective, nonrandomized, experimental study in four Japanese white rabbits and six Yorkshire pigs. ICG and indigo carmine were injected into the tongue, larynx, or hypopharynx, and ICG fluorescence detection was evaluated using both transcutaneous visualization of lymphatic vessels and intraoperative identification of SLNs. RESULTS: The SLNs appeared as shining fluorescent spots with HEMS transcutaneously in rabbits, but no SLNs were detected transcutaneously in pigs. Eleven procedures identified SLNs, but one did not due to a technical problem. CONCLUSIONS: HEMS could become useful for predicting lymph node metastasis during surgery for head and neck cancer.