Ultrasound-based Thyroid Nodule Malignancy Risk Stratification in Differentiating Benign and Malignant Thyroid Nodules：a Comparative Analysis between the C-TIRADS and ATA Guidelines

BackgroundThe 2020 Chinese guidelines for ultrasound malignancy risk stratification of thyroid nodules: the C-TIRADS (C-TIRADS for short) put forward a method for stratifying the malignancy risk of thyroid nodules, but there are few studies about its value in differentiating benign and malignant thyroid nodules.ObjectiveTo compare the value of ultrasound-based thyroid nodule malignancy risk stratification in differentiating malignant and benign thyroid nodule between C-TIRADS and 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: the American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer (ATA guidelines for short) .MethodsA total of 336 inpatients who underwent surgery and ultrasound examination in Bozhou People's Hospital from January 2019 to May 2021 were selected as participants. Four ultrasonologists with a title higher than attending physician were equally randomized into groups A and B for evaluating ultrasonic examination results according to ultrasound-based thyroid nodule malignancy risk stratification in C-TIRADS and ATA guidelines, respectively. The accuracies of ultrasound-based thyroid nodule malignancy stratification in the two guidelines in differentiating malignant and benign thyroid nodules were assessed using intraoperative or postoperative pathological findings (gold standard for diagnosis) , and were further analyzed using ROC analysis.ResultsAccording to intraoperative or postoperative pathological findings, the participants had 367 thyroid nodules in total, including 253 benign nodules and 114 malignant nodules. The nodules were classified as follows according to the TI-RADS in the C-TIRADS by ultrasonologists in group A: (1) 253 benign nodules: 2 were in TI-RADS 5 category, 23, 30, and 80 were in categories 4c, 4b, and 4a, respectively, 103 were in 3 category, and 15 were in 2 category; (2) 114 malignant nodules: 24 were in TI-RADS 5 category, 59 were in 4c category, 22 were in 4b category, 6 were in 4a category and 3 were in 3 category. And the classification of nodules according to the ATA guideline by ultrasonologists in group B was: (1) 253 benign nodules: 13, 53, 47, 118 were high, intermediate, low, and very low suspicion pattern for malignancy, respectively, and 22 were benign pattern; (2) 114 malignant nodules: 76, 24, 8, 6 were high, intermediate, low, and very low suspicion pattern for malignancy, respectively. ROC analysis showed that, AUCs of ultrasound-based thyroid nodule malignancy risk stratification in differentiating malignant and benign thyroid nodules between C-TIRADS and ATA guidelines were 0.890〔95%CI (0.815, 0.918) 〕and 0.780〔95%CI (0.750, 0.876) 〕, with significant difference (Z=13.62, P