Impact of prophylactic central neck lymph node dissection on early recurrence in papillary thyroid carcinoma.

BACKGROUND

Although the role of prophylactic central neck lymph node dissection (CNLD) in the treatment of papillary thyroid carcinoma (PTC) is controversial, many surgeons perform routine prophylactic CNLD. The present study compares local recurrence rates in PTC patients undergoing total thyroidectomy with and without prophylactic CNLD.

MATERIALS AND METHODS

A retrospective review of 206 patients undergoing thyroidectomy for PTC was conducted at two tertiary referral centers. Of these, 81 patients had total thyroidectomy for PTC and a follow-up between 2 and 9 years with a mean of 3.1 years. Of these 81 patients, 45 underwent routine prophylactic CNLD and 36 did not. For those two groups, demographics, clinical and pathologic findings, radioactive iodine (RAI) treatment, and the incidence of recurrence were compared. Univariate statistical analysis was performed.

RESULTS

There was no significant difference in age, gender, multifocality, or extrathyroidal extension for the two groups. Patients with CNLD had an average tumor size of 1.4 cm versus 2 cm in the group without CNLD (p < 0.05). Patients who underwent CNLD had an average of 8 nodes removed, and positive nodes were found in 33%. Patients with CNLD received a higher dose of RAI, 102.7 mCi versus 66.3 mCi (p < 0.05). The incidence of positive nodes correlated with an increased RAI dose (r = 0.55). Rates of parathyroid removal and autotransplantation were higher in the CNLD group, 36 and 16% in the CNLD group versus 22 and 3% in the group without CNLD (p = 0.4 and p = 0.07). Rates of temporary hypocalcemia were higher in the CNLD group (31 versus 5%; p = 0.001), however rates of permanent hypocalcemia were similar, 1/35 in the no CNLD group versus 0/45 in the CNLD group (p = 0.4). There was a higher recurrence rate among patients without CNLD 6/36 (16.7%) versus 2/45 (4.4%), although this difference was not statistically significant (p = 0.13).

CONCLUSIONS

Routine CNLD as an adjunct to total thyroidectomy identifies positive nodes in over 30% of patients with PTC. The discovery of positive nodes is associated with higher doses of RAI for postoperative ablation, and there is a trend toward decreased recurrence in patients undergoing CNLD.