Endoscopic sentinel lymph node biopsy using indocyanine green-neomannosyl human serum albumin.

OBJECTIVE: The aim of this study was to determine the possibility of endoscopic sentinel lymph node biopsy of the head and neck region using indocyanine green-neomannosyl human serum albumin (ICG:MSA) and a custom-made intraoperative color-and-fluorescence-merged imaging system (ICFIS).

METHODS: Using mouse and rabbit models of tongue cancer, we performed sentinel lymph node biopsy using an ICG:MSA tracer and custom imaging system equipped with an endoscope.

RESULTS: ICG:MSA was localized to the cervical lymph node on the ipsilateral side for up to 30 minutes compared to ICG tracer (ICG n = 3, IGC:MSA n = 3). Detection of sentinel lymph nodes was attempted after injecting ICG:MSA in the mouse tongue cancer model (n = 3). During the operation, lymph nodes were easily identified and resected using ICFIS without the aid of other magnifiers. In the rabbit tongue cancer model (n = 3), the ICFIS equipped with 30-degree endoscopy was used to confirm the feasibility of endoscopic sentinel lymph node biopsy. The entire sentinel lymph node biopsy procedure was performed using the ICFIS with the 30-degree endoscope. We detected and dissected sentinel lymph nodes in the rabbit model without the other sentinel lymph node detection tools.

CONCLUSION: We confirmed the usefulness of sentinel lymph node biopsy using a near infrared fluorescence technique and endoscopic system. Avoidance of radiation exposure and shine-through phenomena, which are problems of sentinel lymph node biopsy using conventional radioisotopes, are advantages of our surgical technique. By combining the endoscopic system with a sentinel lymph node biopsy procedure, we avoided visible neck scars, which lead to excellent cosmetic outcomes.

LEVEL OF EVIDENCE: NA. Laryngoscope, 128:E135-E140, 2018.