Diagnostic Performance of Various Ultrasound Risk Stratification Systems for Benign and Malignant Thyroid Nodules: A Meta-Analysis

SIMPLE SUMMARY: In the present study, the sensitivity, specificity, and pooled diagnostic performances according to the cutoff value for diagnosing cancer of five ultrasound risk-stratification systems often used in clinical practice were verified by performing a meta-analysis. Sixty-seven studies involving 76,512 thyroid nodules were included in this research. The highest area under the curve (AUCs) of the K-TIRADS, ACR-TIRADS, ATA classification, EU-TIRADS, and Kwak-TIRADS were 0.904, 0.882, 0.859, 0.843, and 0.929, respectively. Based on the optimal sensitivity and specificity, the AUC or diagnostic odds ratios of K-TIRADS, ACR-TIRADS, ATA, EU-TIRADS, and Kwak-TIRADS were taken as the cutoff values of 4 (intermediate suspicion), TR5 (highly suspicious), high suspicion, 5 (high risk), and 4b, respectively. All ultrasound-based risk-stratification systems had good diagnostic performance. ABSTRACT: Background: To evaluate the diagnostic performance of ultrasound risk-stratification systems for the discrimination of benign and malignant thyroid nodules and to determine the optimal cutoff values of individual risk-stratification systems. Methods: PubMed, Embase, SCOPUS, Web of Science, and Cochrane library databases were searched up to August 2022. Sensitivity and specificity data were collected along with the characteristics of each study related to ultrasound risk stratification systems. Results: Sixty-seven studies involving 76,512 thyroid nodules were included in this research. The sensitivity, specificity, diagnostic odds ratios, and area under the curves by K-TIRADS (4), ACR-TIRADS (TR5), ATA (high suspicion), EU-TIRADS (5), and Kwak-TIRADS (4b) for malignancy risk stratification of thyroid nodules were 92.5%, 63.5%, 69.8%, 70.6%, and 95.8%, respectively; 62.8%, 89.6%, 87.2%, 83.9%, and 63.8%, respectively; 20.7111, 16.8442, 15.7398, 12.2986, and 38.0578, respectively; and 0.792, 0.882, 0.859, 0.843, and 0.929, respectively. Conclusion: All ultrasound-based risk-stratification systems had good diagnostic performance. Although this study determined the best cutoff values in individual risk-stratification systems based on statistical assessment, clinicians could adjust or alter cutoff values based on the clinical purpose of the ultrasound and the reciprocal changes in sensitivity and specificity.