Accuracy of Intraoperative Determination of Central Lymph Node Metastasis by Surgeon in Papillary Thyroid Carcinoma

Abstract

Objectives: Prophylactic central neck dissection (CND) in papillary thyroid carcinoma (PTC) remains controversial because of its potential morbidity and unclear benefit. If we can judge central lymph node metastasis preoperatively or intraoperatively, we can avoid unnecessary CND. However, ultrasound (US)/computed tomography (CT) or sentinel node biopsy is not enough to determine central lymph node metastasis accurately. The aim of this study was to evaluate the accuracy of intraoperative determination of central lymph node metastasis by surgeon during thyroidectomy. Methods: From October 2011 to September 2012, 122 consecutive patients with clinically node negative PTC on US and CT were enrolled. Any suspicious metastatic lymph node on palpation or inspection was sent for frozen biopsy, and then bilateral CND with total thyroidectomy was completed in all patients. The criteria of suspicious lymph node included dark cystic or hard palpable lymph node, or larger than about 7 mm in diameter. We compared the intraoperative surgeon’s judgment with final pathologic results. Results: Suspicious metastatic lymph nodes were found in 37 (30.3%) patients, and 15 of them had metastasis in permanent biopsy. Of 85 patients with no suspicious lymph node, 27 patients had metastasis in permanent biopsy. Sensitivity, specificity, positive predictive value, and negative predictive value of intraoperative determination of lymph node metastasis was 35.7%, 72.5%, 40.5%, and 68.2%, respectively. In 22 of false positive patients, 14 (63.6%) had Hashimoto’s thyroiditis. Conclusions: Intraoperative determination of central lymph node metastasis by surgeon is limited to guide CND in clinically node negative PTC because of its low sensitivity.