Validation of web‐based thyroid imaging reporting and data system in atypia or follicular lesion of undetermined significance thyroid nodules

Background Atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) show variable malignancy risk. We validated the web‐based predictive models and the scoring system by the American College of Radiology (ACR) for AUS/FLUS nodules to stratify the malignancy risk. Methods From January 2011 to November 2014, 275 consecutive nodules diagnosed as AUS/FLUS were enrolled. The discrimination and calibration ability of a web‐based scoring with inclusion of biopsy result and sonographic features, old web‐based scoring model without biopsy result, and ACR models were assessed. Results The areas under the receiver operating characteristic curve of the validation set were 0.670 for the new web‐based model, 0.710 for the old web‐based model, and 0.732 for the ACR scoring risk‐stratification model. All models were well calibrated. Conclusion The web‐based scoring risk‐stratification model using the combined information of ultrasonography features and biopsy result for AUS/FLUS nodules to stratify malignancy risk presents an acceptable predictive accuracy.