Single modality indocyanine green is feasible for sentinel node detection in head and neck cutaneous melanoma: A prospective cohort study

Abstract

Dual modality sentinel lymph node biopsy (SLNB) techniques are most commonly used in melanoma surgery, based on radiocolloid lymphoscintigraphy with either blue dye or indocyanine green (ICG) dye. No studies to date have analysed the use of ICG alone. This study examined the feasibility of ICG as a single modality for detecting sentinel nodes in cutaneous head and neck melanomas. A prospective cohort study was performed of all consecutive cutaneous head and neck melanomas patients between July 2023 and November 2024 undergoing SLNB at a supraregional skin cancer centre in the U.K. Three cohorts were formed: group A (ICG-only); group B (ICG and radiocolloid); and group C (radiocolloid and blue dye). 182 nodes were obtained from 67 patients. Where each technique was utilised, 100% of nodes were detected by ICG; 85% by radiocolloid; and 80% by blue dye. Radiocolloid failed to detect any nodes in three patients, and blue dye failed in four patients. In group B, ICG detected significantly more nodes than radiocolloid (p=0.0004); in group C, there was no difference between radiocolloid and blue dye (p=0.149). Twelve sentinel nodes were positive for melanoma: 100% were ICG positive, 88.9% were radiocolloid positive and 50% were blue dye positive. Single modality ICG is a feasible technique, with nodal detection and metastases detection rates comparable to dual modality. As an intraoperative surgeon-led technique, ICG-alone negates the need for preoperative lymphoscintigraphy with its associated radiation risk and nuclear medicine resource requirements.

Keywords: Indocyanine green; Melanoma; Near-infrared; Sentinel node.