Evaluation of a radioactive and fluorescent hybrid tracer for sentinel lymph node biopsy in head and neck malignancies: prospective randomized clinical trial to compare ICG-(99m)Tc-nanocolloid hybrid tracer versus (99m)Tc-nanocolloid.

Abstract

There is some controversy about the value of sentinel lymph node excision (SLNE) in patients with head and neck malignancies. The gold standard for detection and targeted extirpation of the SLN is lymphoscintigraphy with (99m)Tc-nanocolloid. The purpose of this prospective randomized study was to analyse the feasibility and clinical benefit of a hybrid tracer comprising the near-infrared (NIR) fluorescent indocyanine green (ICG) and (99m)Tc-nanocolloid (ICG-(99m)Tc-nanocolloid) in direct comparison with standard (99m)Tc-nanocolloid for guiding SLNE in patients with head and neck cutaneous malignancies. We analysed the data from 40 clinically lymph node-negative patients with melanoma, high-risk cutaneous squamous cell carcinoma, Merkel cell carcinoma or sweat gland carcinoma who underwent SLNE with ICG-(99m)Tc-nanocolloid (cohort A) or with the standard (99m)Tc-nanocolloid (cohort B). Overall SLNs were identified preoperatively in all 20 patients (100%) in cohort A and in 18 of 20 patients (90%) in cohort B. The SLN basin was detected preoperatively in 18 patients (90%) in cohort A and also in 18 patients (90%) in cohort B. SLNs were identified intraoperatively in all 20 patients (100%) in cohort A and in 19 patients (95%) in cohort B (p = 0.487). Metastatic SLNs were detected in 9 patients (22.5%), 3 (15.0%) in cohort A and 6 (30.0%) in cohort B (p = 0.228). The hybrid tracer ICG-(99m)Tc-nanocolloid is an innovative imaging tracer, reliably and readily providing additional information for the detection and excision of SLN in the head and neck region. Therefore, SLNE with combined radioactive and NIR fluorescence guidance is an attractive option for improving the SLN detection rate in patients with cutaneous head and neck malignancies.