Comparison Of The Clinical Values Of American College Of Radiology TI-RADS And The EU-TIRADS

ObjectiveThe aim of this study was to compare the diagnostic accuracy of American College of Radiology Thyroid Imaging Reporting and Data system(ACR TI-RADS)and European Thyroid Association Guidelines for Ultrasound Malignancy Risk Stratification of Thyroid Nodules in Adults(The EU-TIRADS)in assessing thyroid nodule risks,and to investigate their reliability for indicating fine-needle aspiration(FNA)and their clinical values.MethodsUltrasound images of 446 preoperative thyroid nodules data from 301 patients who underwent thyroidectomy and ultrasonography at The Affiliated Hospital of Taishan Medical University were reviewed retrospectively.Two experienced ultrasound physicians were trained to stratified the above ultrasound images according to ACR TI-RADS and The EU-TIRADS and FNA decision-making or follow-up recommendations were given in combination with the nodule size.According to the postoperative pathology of those nodules,the receiving operating characteristic(ROC)curves were constructed by using IBM SPSS 19.0 statistical software.Youden index were used to get the best cutoff point to calculate the diagnostic value of the two TIRADS.The diagnostic value of this two classifications was analyzed and compared by Mc Nemar-Bowker test.Values P<0.05 was considered for statistical significance.Results301 patients were included in this study,67 males and 234 females.Mean patient age was 42 years±12(standard deviation)(range 25–64years).Of the 446 thyroid nodules,325(72.9%)were benign and 121(27.1%)were malignant.The 121 malignant nodules including 112 papillary thyroid carcinomas(25.1%),3 medullary thyroid carcinomas(0.7%),2follicular thyroid carcinomas(0.4%),2 thyroid squamous cell carcinomas(0.4%)and 2thyroid lymphomas(0.4%).The malignant nodules were classified as ACR TI-RADS TR1,2,3,4 and 5 in 0%,0%,2.8%,5.9% and 81.4% of cases,respectively.The actual malignant proportion of TR2 and TR3 was slightly lower than the reference malignant risk(0% vs 2%,2.8% vs 5%),and the remaining stratification was consistent with the reference malignant risk.The nodules were classified by The EU-TIRADS scores as EU-TIRADS 2,3,4 and 5 in 0%,0.7%,6.0%,68.6% of cases.Except that EU-TIRADS 3 malignancy proportion is lower than the reference malignancy risk(0.7%vs2%-4%),the remaining stratification is coincide with the reference malignant risk.The ROC curves demonstrated that the area under the curve(AUC)of the ACR TIRADS were 0.940,while the AUC of The EU-TIRADS were 0.906.The best cutoff were TR5,EU-TIRADS 5,respectively.The sensitivity,specificity,positive /negative predictive values,false negative rate,false positive rate and accuracy in ACR TI-RADS were 93.4%,92.0%,81.2%,97.3%,6.6%,8.0%,92.4%,respectively,and 95.9%,83.7%,68.6%,98.2%,4.5%,16.3%,87.0%,respectively,in The EU-TIRADS.The ACR TI-RADS demonstrated a statistically higher specificity than The EU-TIRADS(P<0.05),whereas the sensitivity of them has no significant difference(P=0.6).Finally,153 nodules were recommended to FNA by ACR TI-RADS and 232 nodules by The EU-TIRADS,and 58 malignancy nodules were found in both of them.Biopsy yield of malignancy,biopsy rate of malignancy,unnecessary FNA rate in ACR TI-RADS were47.9%,37.9%,and 62.1%,respectively,and 47.9%,25.0%,and 75.0%,respectively,in The EU-TIRADS.The false negative rate of TR3 and TR4 were 3.1%,and 1.7% in EUTIRADS 3 and EU-TIRADS 4.ConclusionBoth ACR TI-RADS and The EU-TIRADS provide an effective risk assessment system for thyroid nodules.Compared with The EU-TIRADS,ACR TI-RADS has a higher diagnostic specificity,but the sensitivity of them has no significant difference.Both ACR TI-RADS and The EU-TIRADS offer a meaningful reduction in the number of thyroid nodules recommended for biopsy,and ACR TI-RADS has a better performence in reduction number of biopsy while The EU-TIRADS has a lower false positive rate.