Comparison of incidentally detected focal FDG uptake in the thyroid gland on PET/CT with fine needle aspiration biopsy results.

OBJECTIVES

To compare the SUV-SUV values of the thyroid gland nodules and the SUV-SUV ratios of the nodules to normal thyroid gland with the fine-needle aspiration biopsy (FNAB) results, to determine the importance of nodule SUV value in the detection of malignancy.

METHODS

This study included 788 patients without a diagnosis of thyroid cancer who exhibited focal uptake in the thyroid gland on 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT. Of these, 131 patients underwent FNAB. SUV-SUV values of the nodules and normal thyroid tissue were measured on PET/CT imaging, along with the pathology reports of the patients who underwent FNAB.

RESULTS

Patients with malignant tumors, nodules exhibited higher SUV and SUV values for both nodules and nodules/normal thyroid tissue ratio compared to those with benign group. The thyroid SUV and SUV values were higher in the benign group. The area under the curve for the nodule SUV was 84.6%, and the cut-off value was determined to be 5.5, with a discrimination ability of 80%-90%.

CONCLUSION

The area under the curve for the nodule SUV showed the statistical significance of the diagnostic discrimination ability of the test. The findings suggest that nodule SUV provides good discrimination ability for malignancy detection, indicating its potential utility as a diagnostic marker.