Effectiveness of Sentinel Lymph Node Biopsy with Pre-epiglottic Tc99 Injection

Objectives: Despite ongoing research and previous successful reports, sentinel lymph node biopsy (SLNB) has not gained widespread use in the management of the neck in laryngeal carcinoma. The aim was to assess the effectiveness of the SLNB technique in laryngeal carcinoma with the novel percutaneous pre-epiglottic radiotracer injection technique. Methodology: Twenty-seven SLNBs of 18 patients with laryngeal squamous cell carcinoma were retrospectively reviewed. T1-3 stage laryngeal cancer patients, either originating or involving the supraglottic region, with no clinically or radiologically proven neck metastasis, were selected for radionuclide injection. All patients required selective neck dissection for their primary tumour. Tc99m-labelled nanocolloid was injected into the pre-epiglottic area. Sentinel lymph nodes (SLNs) were localized and excised on the day of surgery using static lymphoscintigraphy images and a gamma probe. Results: All of the malignant nodes were detected with the SLNB technique and definite pathology results. After considering the definite pathology results with the use of serial step sectioning technique accuracy, negative predictive value, positive predictive value, sensitivity and specificity rates were all found to be 100%. Based on the frozen sections, there were five false negative results in the study. The positive and negative predictive values of the technique was 100% and 76.2%, respectively, regarding frozen sections. Based on the frozen section data, the sensitivity of the SLNB technique was 68.8% and specificity was 100%. Conclusions: Pre-epiglottic percutaneous radiotracer injection is a reliable and safe technique to detect SLNs in laryngeal carcinoma. However the results of the frozen section analysis yielded a lower accuracy rate.