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.


OBJECTIVE
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.


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.


CONCLUSIONS
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.
Department of Nuclear Medicine, Faculty of Medicine, Cukurova University, Adana, Turkey.
Gulgun
G
Buyukdereli
Department of Nuclear Medicine, Faculty of Medicine, Cukurova University, Adana, Turkey.
Yasemin
Y
Aktar
Department of Public Health, Faculty of Medicine, Cukurova University, Adana, Turkey.
Ertan
E
Kara
Department of Pathology, Faculty of Medicine, Cukurova University, Adana, Turkey.
Aysun
A
Uguz
Department of General Surgery, Faculty of Medicine, Cukurova University, Adana, Turkey.
Husnu
H
Sonmez
FDG PET/CT; Fine Needle Aspiration Biopsy; Indeterminate; Thyroid Nodules