Is routine central neck dissection necessary for the treatment of papillary thyroid microcarcinoma?

It remains unclear as to whether routine central neck dissection (CND) is necessary when performing surgery to treat patients with papillary thyroid microcarcinoma (PTMC). To determine the necessity for routine CND in PTMC patients, we reviewed the clinicopathologic and laboratory data of the patients of PTMC.

Between September 2001 and July 2005, 101 patients with PTMC and clinical N0 disease were retrospectively reviewed. The study cohort was devided into groups: the total thyroidectomy plus CND group (the CND group, N=48) and the total thyroidectomy without CND group (the no CND group, N=53). The serum stimulated thyroglobulin (Tg) levels were measured after surgery and prior to radioactive iodine ablation therapy (RAI) and at 6-12 months after RAI. Pathology, the Tg levels and recurrence data were compared between the 2 groups.

Central nodal metastases were found in 18 of the 48 CND patients (37.5%). The incidence of Tg levels >5 ng/mL at RAI was higher in the no CND patients and in the 18 node-positive CND patients compared with the 30 node-negative CND patients (22-24% vs. 3%, respectively, P=0.020-0.058). The difference when performing a similar comparison using a >2 ng/mL Tg threshold level showed no significance (10-11% vs. 4%, respectively, P>0.1). Two of the no CND patients and one node-positive CND patient had recurrences in the thyroid bed or lateral neck during a mean follow-up of 24 months.

The data showed that occult metastasis to the central neck is common in PTMC patients. A CND provides pathologic information about the nodal metastases, and it potentially provides guidance for planning the postoperative RAI. However, the long-term benefit of CND on recurrence and survival remains somewhat questionable.