Lateral Neck Dissection for Well-Differentiated Thyroid Carcinoma: Is Prophylactic Level V Neck Dissection Necessary? A Retrospective Cohort Study

Objective: The presence of clinically detectable papillary thyroid carcinoma (PTC) metastases in the lateral neck is an indication for neck dissection (ND) and thyroidectomy. Although there is a consensus regarding the importance of therapeutic selective ND of involved levels II to IV in patients with clinically evident locoregional metastatic disease, the prognostic benefit of level V prophylactic ND remains debatable. Methods: All patients who underwent thyroidectomy with ND for metastatic PTC between 2006 and 2019 were included in a single-institution retrospective study. Preoperative characteristics at initial presentation, imaging workup, intraoperative findings, and the final histopathological reports were retrieved from the institutional database. Results: A total of 189 patients with locally advanced PTC were identified, of whom 22 (11.6%) patients underwent therapeutic selective ND at levels II to IV together with level V dissection due to clinical involvement. Comparison of the patients who were operated on level V to those who were not revealed no significant difference. The disease recurrence rate was 20.1% throughout an average follow-up of 5.1±3.1 years. No significant differences in recurrence rate were found between patients who underwent and those who did not undergo level V ND (22.7% vs 19.8%, P =.648). No recurrence at resected level V was detected during follow-up, while recurrence at level V was found in 4 (2.1%) patients who did not undergo level V dissection. Evidence of macroscopic and microscopic extrathyroidal extension was significant predictors of disease recurrence risk. Conclusion: There were no significant associations between level V dissection and risk for recurrence. Recurrence at level V was rare (4/189 patients, 2.1%). Our study’s findings suggest a low prophylactic benefit of an elective level V ND. Elective level V ND should not be done routinely when lateral ND is indicated but should rather be considered after careful evaluation in high-risk patients.