Characteristics and Detection Rate of Thyroidal Incidentaloma using ¹⁸F-FDG PET-CT / 대한내분비외과학회지

ABSTRACT

PURPOSE: PET-CT is often used to differentiate benign or malignant thyroid incidentalomas. In this retrospective study, we evaluated whether the ¹⁸F-FDG uptake pattern and PET-CT findings improved accuracy over the standardized uptake value (SUV). METHODS: ¹⁸F-FDG PET-CT was performed on 2,178 subjects from August, 2004, to October, 2007, in Sung-ae Hospital. PET-CT was performed on 806 patients (37%) with suspected or known nonthyroidal cancer and 1,372 healthy subjects (63%) without a previous history of cancer. We investigated the clinical characteristics of patients, history, standardized uptake value (SUV), ultrasonography, and hormone levels in blood. Thyroidal cancer was confirmed by ultrasonography-guided fine needle aspiration and pathology after thyroid operation. RESULTS: The prevalence of focal thyroid lesions on PET-CT was 8.8% (191/2178). Thyroid cancer confirmation was 7.9% (15/191). The maximum SUV of malignant thyroid lesions were significantly higher than that of benign lesions (7.00±3.08 vs. 4.49±1.84, P<0.001). CONCLUSION: PET-CT image interpretation that includes 18F-FDG uptake and SUV is better than PET-CT alone for differentiating benign and malignant lesions. Thyroid cancer risk increases as SUVmax levels increase.