Sonographic Analysis of Malignant Thyroid Nodules by Surgeon / 대한내분비외과학회지

PURPOSE: Ultrasound is most effective study for evaluating thyroid nodules. In this review, we discuss that sonographic findings to differentiate benign from malignant nodules and suggest recommendations for indications of fine needle aspiration biopsy and thyroid nodule management. METHODS: Sonographic scans of 206 thyroid nodules in 164 patients were candidated for this study. We evaluated sonographic findings by shape, calcification, margin, and echogenicity, retrospectively. Sonographic findings that suggested malignancy included microcalcifications, a speculated margin, marked hypoechogenicity and a shape that was taller than wide. The final diagnosis of lesion as benign (n=180) or malignant (n=26) was confirmed by fine needle aspiration biopsy and follow-up (>6 months). We demonstrated the difference of the sensitivity, specificity, positive predictive value, negative predictive value and accuracy. RESULTS: Of 206 thyroid nodules, 26 were malignant. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy based on our sonographic classification method were 84.6%, 73.9%, 31.9%, 97.0% and 75.2%. CONCLUSION: Sonography can be helpful for making the differentiation between and malignant nodules. So, when well trained surgeon find thyroid nodules on sonography, we can make correct diagnosis of malignant nodules.

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

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.