^99mTc-Tilmanocept vs. Sulfur Colloid for Sentinel Node Biopsy for Melanoma in the Head and Neck

The objective of the study is to compare sentinel lymph node (SLN) identification rates and performance characteristics of lymphoscintigraphy using ^99mTc-sulfur colloid (SC) and ^99mTc-tilmanocept (TL) for head and neck cutaneous melanoma. This study is a retrospective study, conducted at a single, tertiary care cancer center. Patients underwent sentinel lymph node biopsy (SLNB) for head and neck cutaneous melanoma, using SC or TL, between October 2014 and February 2019. Differences in SLN identification rates and performance characteristics between the groups were examined using the Mann-Whitney, or Fisher's exact test. Sixty patients underwent SLNB, of which 19 employed TL. There were no significant differences between SC vs. TL in operative duration (116 vs. 127 min, P = 0.97), radiation dose (530 vs. 547 μCi, P = 0.27), median number of SLNs removed (3 vs. 2, P = 0.32), or median follow-up (46.3 vs. 38.4 months, P = 0.11). The rates of positive SLNs (17% vs. 37%, P = 0.11), intraoperative non-localization (12% vs. 16%, P = 0.70), and false-negative SLNB (5% each, P = 1.00) were not significantly different between groups. In patients with head and neck melanoma undergoing SLNB, ^99mTc-tilmanocept may not differ from ^99mTc-sulfur colloid in identifying SLNs or other performance characteristics. The added expense related to ^99mTc-tilmanocept and lack of favorable performance data should urge caution in its adoption and promote further examination of its value in similar patient cohorts.