Significance of Â¹â¸F FDG PET-CT for Preoperative Diagnosis of Cervical Lymph Nodes Metastasis in Papillary Thyroid Carinoma

Kim, Su Ran; Kang, Hyun Jong; Park, Kyoung Sik; Paik, Nam Sun; Yoo, Young Bum

Abstract

PURPOSE
To compare the diagnostic accuracy of US/CT with US/CT/¹â¸F-FDG PET-CT in the diagnosis of cervical lymph nodes metastasis in papillary thyroid carcinoma.
METHODS
From July 2008 to May 2010, 36 patients with papillary thyroid carcinoma, confirmed by aspiration cytology analysis, underwent neck US, neck CT and ¹â¸F-FDG PET-CT preoperatively. The sensitivity, specificity and diagnostic accuracy of the US/CT, US/CT/PET-CT was analyzed according to lymph node level (all: levels I~VI, central: level VI, lateral: levels I~V).
RESULTS
At all lymph nodes group (level I~VI), US/CT/ PET-CT showed a sensitivity of 66.6%, a specificity of 61.9% and a diagnostic accuracy of 63.8%. The corresponding values for US/CT were 60.0%, 85.7%, 75.0% respectively. Considering the central cervical nodes group (level VI), US/CT/PET-CT showed a sensitivity of 57.1%, a specificity of 68.1%, and a diagnostic accuracy of 63.8%. The corresponding values of US/CT were 57.1%, 90.9%, 77.7% respectively. Considering the lateral cervical nodes group (level I~V), US/CT/PET-CT showed a sensitivity of 100%, a specificity of 84.3%, and a diagnostic accuracy of 86.1%. The corresponding values of US/CT were 75.0%, 84.3%, 83.3% respectively. The diagnostic results of US/ CT, US/CT/PET-CT in initial evaluation of the cervical nodes metastasis did not differ significantly.
CONCLUSION
Our preliminary results suggest that additional PET-CT evaluation in US/CT does not provide statistically significant benefit for initial diagnosis of cervical lymph nodes metastasis in papillary thyroid carcinoma.