The European Institute of Oncology Thyroid Imaging Reporting and Data System for Classification of Thyroid Nodules: A Prospective Study

Background: To evaluate the performance, quality and effectiveness of "IEO-TIRADS" in assigning a TI-RADS score to thyroid nodules (TN) when compared with "EU-TIRADS" and the US risk score calculated with the S-Detect software ("S-Detect"). The primary objective is the evaluation of diagnostic accuracy (DA) by "IEO-TIRADS", "S-Detect" and "EU-TIRADS", and the secondary objective is to evaluate the diagnostic performances of the scores, using the histological report as the gold standard. Methods: A radiologist collected all three scores of the TNs detected and determined the risk of malignancy. The results of all the scores were compared with the histological specimens. The sensitivity (SE), specificity (SP), and diagnostic accuracy (DA), with their 95% confidence interval (95% CI), were calculated for each method. Results: 140 TNs were observed in 93 patients and classified according to all three scores. "IEO-TIRADS" has an SE of 73.6%, an SP of 59.2% and a DA of 68.6%. "EU-TIRADS" has an SE of 90.1%, an SP of 32.7% and a DA of 70.0%. "S-Detect" has an SE of 67.0%, an SP of 69.4% and a DA of 67.9%. Conclusion: "IEO-TIRADS" has a similar diagnostic performance to "S-Detect" and "EU-TIRADS". Providing a comparable DA with other reporting systems, IEO-TIRADS holds the potential of being applied in clinical practice.