Comparative Diagnostic Performance of Ultrasound-Based Risk Stratification Systems in Thyroid Nodule Evaluations by...

Background/Objectives: Thyroid nodules are a prevalent condition with a high incidence rate of malignancy. Ultrasound (US)-based risk stratification systems have become widely utilized for the evaluation of thyroid nodules, including the American Thyroid Association (ATA) guidelines, the American College of Radiology Thyroid Imaging Reporting and Data System (ACR-TIRADS), the Korean Society of Thyroid Radiology system (K-TIRADS), and the European Thyroid Association system (EU-TIRADS). Our institution has developed a real-time computerized score for evaluating thyroid nodules. This study aims to systematically compare the diagnostic performance of these systems when applied in real time by otolaryngologists, who integrate dynamic US imaging with physical examination. Methods: Patients with thyroid nodules who underwent US evaluation, US-guided fine-needle aspiration cytology (FNAC), and subsequent thyroidectomy were included. During each examination, otolaryngologists performed real-time risk categorization according to five US-based systems, with immediate scoring based on dynamic sonographic findings. Results: From April 2021 to November 2023, 130 patients were enrolled. For categories 4 and 5, the ATA guidelines had a sensitivity of 96.6% (95% CI: 87.3-100%), specificity of 78.9%, (60.6-97.3%) PPV of 84.6% (70.7-98.5%), NPV of 93.7% (81.9-100%), and accuracy of 88.1% (78.3-97.9%). The sensitivity of the ACR-TIRADS was 95.6% (87.3-100%), the specificity was 78.9% (60.6-97.3%), the PPV was 84.6% (70.7-98.5%), the NPV was 93.7% (81.9-100%), and the accuracy was 88.1% (78.3-97.9%). Both the K-TIRADS and the EU-TIRADS had sensitivities of 95.6% (87.3-100%), specificities of 78.9% (60.6-97.3%), PPVs of 84.6% (70.7-98.5%), NPVs of 93.7% (81.9-100%), and accuracies of 88.1% (78.3-97.9%). The computerized score (>3.3 considered malignant) and TBSRTC (Category 5 or 6) both had sensitivities of 73.9% (56.0-91.9%), specificities of 100%, PPVs of 100%, NPVs of 76.0% (59.3-92.7%), and accuracies of 85.7% (75.1-96.3%). Conclusions: Otolaryngologists can achieve highly accurate diagnostic performance when applying standardized ultrasound-based risk stratification systems, and a real-time computerized scoring system provides highly specific supplemental value for immediate clinical decision-making.