Randomized trial of prophylactic ipsilateral central lymph node dissection in patients with clinically node negative papillary thyroid microcarcinoma

Purpose: This study aimed to evaluate the role of prophylactic ipsilateral central neck dissection (pCND) in patients with clinically node-negative (cN0) papillary thyroid microcarcinoma (PTMC). Methods: In this randomized control trial, a total of 164 consecutive patients were enrolled. By double-blinded randomization protocol, patients were allocated into hemithyroidectomy with pCND (n = 82) or without pCND (n = 82). With intention-to-treat analysis, post-surgical pathological and clinical course, surgery-related complications, causes and clinical course of protocol-violated cases and 5-year recurrence-free survival were compared. Results: Operation time, hospital stay, and post-surgical complication were not significantly different between the two groups. In the pCND (+) group, occult lymph node metastasis rate was 50.0%, and lymph node ratio (metastatic/harvested lymph nodes) was 45.2%. Ten patients in the pCND (+) group had converted to undergo onsite or staged completion total thyroidectomy due to the presence of metastatic central lymph nodes and/or positive resection margin. Until last follow-up (mean 73.4 months), one regional recurrence developed in the pCND (−) group, and three regional recurrences occurred in the pCND (+) group. Five-year recurrence-free survival was similar between the two groups. Conclusion: Although ipsilateral pCND could clear occult lymph node metastasis in the central compartment, it failed to provide any oncological benefit for cN0 PTMC patients.