Detection of Metastatic Cervical Lymph Nodes in Recurrent Papillary Thyroid Carcinoma: Computed Tomography Versus Positron Emission Tomography-Computed Tomography

Abstract

Objective: We sought to determine whether positron emission tomography-computed tomography (PET-CT) is more accurate than CT for detecting metastatic cervical lymph nodes in recurrent papillary thyroid carcinoma (PTC) and to determine the relationship between the CT features and PET-CT findings of metastatic nodes. Methods: Eleven consecutive patients with recurrent PTC underwent contrast-enhanced CT (CECT) and PET-CT before surgery. We retrospectively evaluated CECT and PET-CT images to determine the presence of metastatic nodes by level-by-level analysis. The CT findings of the PET-CT results that were positive and negative for metastatic nodes were compared. Results: Metastatic nodes were found at 28 (78%) of 36 neck levels surgically explored. The sensitivity, specificity, and accuracy of CECT for the detection of metastatic nodes were 75.0%, 87.5%, and 77.8%, respectively, and those of PET-CT were 35.7%, 87.5%, and 48.6%, respectively, by level-by-level analysis. No significant difference in the CT features was found between the PET-CT findings positive and negative for metastatic nodes (P > 0.05). Conclusions: Computed tomography is more sensitive and accurate than PET-CT for detecting metastatic lymph nodes in recurrent PTC. No significant relationship was found between the CT features and the PET-CT findings of the metastatic nodes.