Predictive Factors of Level II Lymph Node Metastasis in N1b Papillary Thyroid Carcinoma Patients / 대한이비인후과학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: Cervical lymph node (LN) metastases are common in papillary thyroid carcinoma (PTC) and cervical neck dissection (ND) is frequently performed to improve regional control of the disease. However, there is a controversy as to the extent of lateral cervical ND. In the present study, we examined the diagnostic accuracy of ultrasonography (US) or CT and the predictive factors of level II LN metastases in PTC patients with clinically positive lateral neck nodes. SUBJECTS AND METHOD: We retrospectively analyzed 78 patients who underwent thyroidectomy and lateral ND including level II LN between August 1998 to June 2008. To identify predictive factors of cervical node metastases to level II, diverse factors were analyzed. RESULTS: The most common site of metastasis was level IV (83.3% of cases). The accuracy of diagnostic imaging in the detection of level II metastasis revealed sensitivity of 89.4%, and specificity of 93.5%. The results of the univariate analysis showed that the presence of level II metastases was significantly associated with the location of primary tumor (p<0.001), number of metastatic LN (p=0.001), and great size of metastatic LN (p=0.010). In addition, the multivariate analysis showed that the location of primary tumor and number of metastatic LN were an independent risk factor for the presence of level II metastasis. CONCLUSION: Preoperative imaging was accurate for detecting the presence of level II LN metastasis. Patients with upper lobe tumor and multiple metastatic LN have a higher risk of harboring metastatic disease at the level II. We suggest that routine dissection of the level II LN may not be necessary for patients with no evidence of diagnostic imaging and predictive factors of level II LN metastasis.