Impact of the Hypoechogenicity Criteria on Thyroid Nodule Malignancy Risk Stratification Performance by Different TIRADS Systems

Abstract

Background: Various Thyroid Imaging and Reporting data systems (TIRADS) are used worldwide for risk stratification of thyroid nodules. Their sensitivity is high, while the specificity is suboptimal. The aim of the study was to compare several TIRADS systems and evaluate the effect of hypoechogenicity as a sign of risk of malignancy on the overall assessment of diagnostic accuracy. Methods: The prospective study includes 274 patients with 289 thyroid nodules to whom US and risk of malignancy were assessed according to four TIRADS systems—European (EU-TIRADS), Korean (K-TIRADS), TIRADS by American College of Radiology (ACR TIRADS), and modified Kwak et al. TIRADS (L-TIRADS) systems, in which mild hypoechogenicity is not included in malignancy risk suggestive signs. For all thyroid nodules, a fine needle aspiration (FNA) biopsy was performed and evaluated according to the Bethesda system. For all systems, diagnostic accuracy was calculated. Results: Assessing the echogenicity of the thyroid nodules: from 81 of isoechogenic nodules, 2 were malignant (2.1%), from 151 mild hypoechogenic, 18 (12%) were malignant, and from 48 marked hypoechogenic nodules, 16 (33%) were malignant. In 80 thyroid nodules, mild hypoechogenicity was the only sign of malignancy and none appeared malignant. Assessing various TIRADS systems on the same cohort, sensitivity, specificity, PPV, NPV, and accuracy, firstly for EU-TIRADS, they were 97.2%; 39.9%; 18.7%; 99.0%, and 73.3%, respectively; for K-TIRADS they were 97.2%; 46.6%; 20.6%; 99.2%, and 53.9%; for ACR-TIRADS they were 97.2%; 41.1%, 19.0%; 99.0%, and 48.0%, respectively; finally, for L-TIRADS they were 80.6%; 72.7%; 29.6%; 96.3%, and 73.3%. Conclusions: This comparative research has highlighted that applying different TIRADS systems can alter the number of necessary biopsies by re-categorization of the thyroid nodules. The main pattern that affected differences was inconsistent hypoechogenicity interpretation, giving the accuracy superiority to the systems that raise the malignancy risk with marked hypoechogenicity, at the same time with minor compensation for sensitivity.

Diagnostic efficiency among Eu-/C-/ACR-TIRADS and S-Detect for thyroid nodules: a systematic review and network meta-analysis

“…After meta-analysis, in the best risk category threshold TR5 of ACR TIRADS, sensitivity ranged from 65% to 76%; specificity ranged from 84% to 89%; and accuracy ranged from 77% to 80%. 37 studies evaluated Eu-TIRADS ( 20 , 22 , 28 , 48 , 55 , 65 , 66 , 70 , 73 , 74 , 78 , 80 – 82 , 85 , 86 , 92 , 93 , 95 , 99 – 101 , 115 , 118 , 121 , 125 – 136 ). After meta-analysis, in the best risk category threshold TR5 of Eu-TIRADS, sensitivity ranged from 66% to 82%; specificity ranged from 75% to 87%; and accuracy ranged from 74% to 82%.…”

Advancements in Ultrasound and Ultrasound-Based Risk Stratification Systems for the Assessment of Thyroid Nodule

“…Thermal ablation of benign thyroid nodules can represent another pitfall when we face previously treated patients and this was addressed by Bernardi et al [ 6 ]. Other specific data have been reported about the role of contrast-enhanced US [ 7 ], grading of hypogenicity [ 8 ], assessment of neck lymph-nodes [ 9 ], and the potential future impacts of artificial intelligence on the thyroid field [ 10 ]. Moreover, how particular thyroid nodules, such as autonomously functioning nodules, may be put in the TIRADSs categories are reported by Seifert et al [ 11 ].…”