Purpose: Papillary thyroid carcinoma (PTC) frequently metastasizes to and recurs in regional lymph nodes. Of the two compartments, the central compartment can be dissected through the same wound as the thyroidectomy, and the central node dissection (CND) is routinely performed in most Japanese surgical departments. However, the indications for prophylactic lateral compartment dissection (modified radical neck dissection [MND]) for low-risk PTC remain unclear. In this study, we investigated the indications for prophylactic MND for PTC patients with tumor measuring 1.1-3.0 cm without significant extrathyroid extension or distant metastasis.
Methods: We investigated the lymph node disease-free survival (LN-DFS) rates of 829 patients who underwent CND and of 414 patients who underwent MND and CND between 2005 and 2007 at Kuma Hospital.
Results: The LN-DFS of these two groups was not significantly different. In the subset of patients with CND only, clinical central node metastasis (N1a) significantly predicted a worse LN-DFS. All N1a patients recognized as showing recurrence developed such recurrence in the lateral compartment. Other conventional prognostic factors, such as sex and age, were not related to LN-DFS.
Conclusion: Taken together, N1a patients with low-risk PTC measuring 1.1-3.0 cm can be considered as candidates for prophylactic MND.