role of 18f-fluorodeoxyglucose positron emission tomography/computed tomography in the evaluation of cytologically indeterminate thyroid nodules

Background: thyroid nodules with indeterminate fine-needle aspiration biopsy (fnab) results remain a diagnostic dilemma, because 70 - 85% of these nodules have been found to be benign after thyroid surgery. objectives: the purpose of this study was to evaluate the usefulness of 18f-fluorodeoxyglucose (fdg) positron emission tomography/computed tomography (pet/ct) in the preoperative diagnosis of cytologically indeterminate nodules. patients and methods: forty-six patients were included in this study. these individuals had undergone fdg pet/cts for the preoperative evaluation of thyroid nodules with indeterminate fnab results. the results of the preoperative pet/ct scans were compared with the postoperative pathological results and statistically analyzed. results: of the 46 patients included in our study, the histopathology of the surgical specimens revealed thyroid cancer in 17 individuals (37%, 17/46). the pet/ct scan showed a positive result in 27 patients. of these, 16 patients (59.3%) were found to have thyroid carcinomas. in addition, the pet/ct scan was considered to be negative in 19 patients, 18 (94.7%) of whom had benign lesions. for the detection of malignant lesions, the values for the sensitivity and specificity, and the positive predictive and negative predictive values were 94%, 62%, 59%, and 95%, respectively. conclusion: the fdg pet/ct showed a high sensitivity and a high negative predictive value for identifying malignancies in thyroid nodules with indeterminate fnab results. therefore, the fdg pet/ct may be a helpful tool in the clinical management of these nodules. when an fdg positive lesion is detected, further examination is recommended.