Does Tilmanocept based lymphoscintigraphy measure up against colloid-based lymphoscintigraphy for sentinel node biopsy in melanoma and early oral squamous cell cancer?

OBJECTIVE: Sentinel lymph node biopsy (SLNB) is crucial in cutaneous melanoma and oral cavity squamous cell carcinoma (OCSCC) as it directs the need for systemic therapy. There has been growing interest in Technetium-99m-labeled Tilmanocept (TL) due to its specific binding capability. This study compares the efficacy of TL to 99mTc-antimony sulphide colloid (ASC), in these two biologically distinct cancers.

DESIGN: In this prospective cross-sectional study, 40 patients were included in each radiotracer group. The primary outcomes measured SN identification rate on lymphoscintigraphy and surgical node retrieval rate. Secondary outcomes include pathological status of lymph nodes, false negative rates (FNR), and nodal recurrence.

RESULT: TL had comparable outcome to ASC with a 100 % SN detection and retrieval rate. Both radiotracers had 100 % lymph nodal tissue specificity with an FNR rate of 0 % for both radiotracers in CM and 25 % for TL in OCSCC. There were significant differences between the SN detection and retrieval rates in ASC in CM and OCSCC but not TL, reflecting its superior binding capability.

CONCLUSION: Our study is the first to demonstrate the superior molecular binding capability of TL with minimal migration to the second echelon nodes.