Kim MJ, Back K, Choe JH, et al. - In the present study, the researchers sought to assess the usefulness of lateral sentinel lymph node biopsy (SLNB) in determining lateral neck dissection (LND) of patients with medullary thyroid cancer (MTC). From January 2013 to June 2019, 16 MTC patients were enrolled in the study. Intratumoral injection of technetium (Tc)-99m phytate followed by lymphoscintigraphy was conducted preoperatively. The identification rate of radioisotope-detected sentinel lymph nodes was 87.5% (14 of 16 patients). Frozen analyses had sensitivity, specificity, positive predictive value, and negative predictive value of 66.7%, 100%, 100%, and 91.6%, respectively. However, based on final histopathology, the diagnostic values of lateral SLNB were all 100%. This study demonstrated that lateral SLNB can be a promising surgical tool for deciding on LND in MTC patients.