Abstract: Background and purpose: Thyroid carcinoma is a common endocrine tumor with an incidence that has increased over recent decades. The aim of the present study was to investigate the effectiveness of carbon nano-particles-labeled lymph nodes in neck dissection for papillary thyroid cancer (PTC), focusing on the protectiveness for the recurrent laryngeal nerve (RLN) and parathyroid glands. Methods: Forty-eight patients with PTC treated from Apr. to Aug. 2015 were randomly divided into two groups. Group A patients (24 patients) were treated with lobectomy/total thyroidectomy plus unilateral/bilateral central lymph node dissection by conventional meticulous capsular dissection technique; Group B patients (24 patients) were treated with the same surgical procedures as group A, 5 min after the injection of carbon nano-particles. The operative time, intra-operative blood loss, incidence of RLN injury, incidence of transient hypocalcemia, the number of total lymph nodes and the ratio of metastatic nodes were collected and analyzed. Results: For unilateral lobectomy, the number of lymph nodes in group B was significantly greater than that in group A (P<0.05). For total thyroidectomy, the operative time, and the incidence of transient hypocalcemia in group B were both lower than those in group A (P<0.05), and the number of total lymph nodes was significantly higher than that in group A (P<0.05). In group B, the ratio of metastatic nodes were 26.7% (unilateral) and 33.3% (bilateral) in stained lymph nodes, and 11.8% and 25.9% in non-stained lymph nodes. Conclusion: The carbon nano-particles-labeled lymph nodes in neck dissection could facilitate to protect parathyroids and increase the number of lymph nodes, especially in total thyroidectomy plus bilateral central lymph node dissection.

Key words: Carbon nano-particles, Papillary thyroid cancer, Surgery, Effectiveness