Diagnostic performance of European and ACR-TIRADS classification systems in thyroid nodules over 20 mm in diameter.

BACKGROUND: The challenge of selecting thyroid nodules for fine-needle aspiration (FNA) cytology has led to the development of the Thyroid Imaging Reporting and Data System (TIRADS), primarily in two formats: EU-TIRADS and ACR-TIRADS. Clinical observations suggest imperfect risk assessment for TIRADS 3 nodules ≥20 mm. This study aimed to evaluate the efficacy of TIRADS systems in distinguishing benign from malignant nodules in this subgroup. MATERIALS AND METHODS: From May 2023 to March 2024, 1,094 patients with thyroid nodules were referred for ultrasound (US) at a University Hospital. Data on clinical, ultrasound, cytological, and histopathological parameters were collected. Nodules ≥20 mm were categorized by EU-TIRADS and ACR-TIRADS, and their predictive performance for malignancy was assessed through post-thyroidectomy histopathology or FNA cytology (Bethesda classification). RESULTS: 267 patients (mean age 60.3 ± 14.3 years; 46 men, 221 women) with 308 nodules were analyzed. Twenty-two malignancies and 286 benign nodules were recorded. Recalculating EU-TIRADS 3 performance using 25 mm and 30 mm thresholds (ACR-modified EU-TIRADS) avoided 24% and 41% of FNAs, respectively, while ACR-TIRADS would prevent 26.6% (p>0.05). Two malignancies were missed. CONCLUSION: EU-TIRADS and ACR-TIRADS show similar efficacy when using a 25 mm FNA threshold. Raising the cut-off for FNA in EU-TIRADS 3 nodules could reduce unnecessary procedures but may increase the risk of missed malignancies, impacting patient outcomes.

Interobserver Agreement in Ultrasound Risk Stratification Systems for Thyroid Nodules on Static Images Versus Cine-Loop Video Sequences.

PURPOSE: To evaluate the impact of video sequences (cine-loops) on the interobserver agreement (IOA) using risk stratification systems (RSSs) for thyroid nodules (TNs). METHODS: Twenty TNs were randomly selected from a large database and evaluated by twelve experienced observers using five different RSSs (Kwak-, ACR-, EU-, Korean-TIRADS, ATA Guidelines). In the first step, the evaluation was conducted based on static ultrasound (US) images in two planes ("static"). Six months later, these cases were reevaluated by the same observers using video sequences in two planes ("cine-loops"). Fleiss' kappa (κ) was calculated for the IOA analyses. RESULTS: IOA on static was moderate with κ values of 0.46, 0.42, 0.40, 0.45, and 0.38 for the Kwak-, ACR-, EU-, Korean-TIRADS, and ATA Guidelines, respectively, while the IOA on cine-loops was fair with κ values of 0.41, 0.38, 0.37, 0.36, and 0.34 for the Kwak-, ACR-, EU-, Korean-TIRADS, and ATA Guidelines, respectively. The overall IOA was superior in static images versus cine-loops (p = 0.024). Among other findings, the subgroup analyses (related to age, gender, US certificates, number of thyroid US per week, and RSSs experience) particularly showed that the experience of the observers in using RSSs had a significant influence on the IOA. CONCLUSIONS: The overall IOA (all twelve observers and all five RSSs) was superior on static US images in comparison to cine-loops. Furthermore, the overall IOA of the five US features revealed superior κ values of the static images over cine-loops. However, this impact was significantly lower when the observers were highly experienced in the use of US RSSs of TNs.

A model based on C-TIRADS combined with SWE for predicting Bethesda I thyroid nodules.

Objectives: This study aimed to explore the performance of a model based on Chinese Thyroid Imaging Reporting and Data Systems (C-TIRADS), clinical characteristics, and shear wave elastography (SWE) for the prediction of Bethesda I thyroid nodules before fine needle aspiration (FNA). Materials and methods: A total of 267 thyroid nodules from 267 patients were enrolled. Ultrasound and SWE were performed for all nodules before FNA. The nodules were scored according to the 2020 C-TIRADS, and the ultrasound and SWE characteristics of Bethesda I and non-I thyroid nodules were compared. The independent predictors were determined by univariate analysis and multivariate logistic regression analysis. A predictive model was established based on independent predictors, and the sensitivity, specificity, and area under the curve (AUC) of the independent predictors were compared with that of the model. Results: Our study found that the maximum diameter of nodules that ranged from 15 to 20 mm, the C-TIRADS category <4C, and E max <52.5 kPa were independent predictors for Bethesda I thyroid nodules. Based on multiple logistic regression, a predictive model was established: Logit (p) = -3.491 + 1.630 × maximum diameter + 1.719 × C-TIRADS category + 1.046 × E max (kPa). The AUC of the model was 0.769 (95% CI: 0.700-0.838), which was significantly higher than that of the independent predictors alone. Conclusion: We developed a predictive model for predicting Bethesda I thyroid nodules. It might be beneficial to the clinical optimization of FNA strategy in advance and to improve the accurate diagnostic rate of the first FNA, reducing repeated FNA.

Thyroid Imaging Reporting and Data Systems: Applicability of the "Taller than Wide" Criterium in Primary/Secondary Care Units and the Role of Thyroid Scintigraphy.

BACKGROUND: To examine the applicability of the "taller than wide" (ttw) criterium for risk assessment of thyroid nodules (TNs) in primary/secondary care units and the role of thyroid scintigraphy therein. METHODS: German bicenter study performed in a setting of primary/secondary care. Patient recruitment and analysis in center A was conducted in a prospective manner. In center B, patient data were retrieved from a database that was originally generated by prospective data collection. TNs were assessed by ultrasound and thyroid scans, mostly fine needle biopsy and occasionally surgery and others. In center A, only patients who presented for the first time were included. The inclusion criterion was any TN ≥ 10 mm that had at least the following two sonographic risk features: solidity and a ttw shape. In center B, consecutive patients who had at least ttw and hypofunctioning nodules ≥ 10 mm were retrieved from the above-mentioned database. The risk of malignancy was determined according to a mixed reference standard and compared with literature data. RESULTS: In center A, 223 patients with 259 TNs were included into the study. For further analysis, 200 nodules with a reference standard were available. The overall malignancy rate was 2.5% (upper limit of the 95% CI: 5.1%). After the exclusion of scintigraphically hyperfunctioning nodules, the malignancy rate increased slightly to 2.8% (upper limit of the 95% CI: 5.7%). Malignant nodules exhibited sonographic risk features additional to solidity and ttw shape more often than benign ones. In addition to the exclusion of hyperfunctioning nodules, when considering only nodules without additional US risk features, i.e., exclusively solid and ttw-nodules, the malignancy rate decreased to 0.9% (upper limit 95% CI: 3.7%). In center B, from 58 patients, 58 ttw and hypofunctioning TNs on thyroid scans with a reference standard were available. Malignant nodules from center B were always solid and hypoechoic. The overall malignancy rate of hypofunctioning and ttw nodules was 21%, with the lower limit of the 95% CI (one-sided) being 12%. CONCLUSIONS: In primary/secondary care units, the lowest TIRADS categories for indicating FNB, e.g., applying one out of five sonographic risk features, may not be appropriate owing to the much lower a priori malignancy risk in TNs compared to tertiary/quaternary care units. Even the combination of two sonographic risk features, "solidity" and "ttw", may only be appropriate in a limited fashion. In contrast, the preselection of TNs according to hypofunctioning findings on thyroid scans clearly warranted FNB, even when applying only one sonographic risk criterion ("ttw"). For this reason, thyroid scans in TNs may not only be indicated to rule out hyperfunctioning nodules from FNB but also to rule in hypofunctioning ones.

Validation of Four Thyroid Ultrasound Risk Stratification Systems in Patients with Hashimoto's Thyroiditis; Impact of Changes in the Threshold for Nodule's Shape Criterion.

The aim of the study was to validate thyroid US malignancy features, especially the nodule's shape, and selected Thyroid Imaging Reporting and Data Systems (EU-TIRADS; K-TIRADS; ACR-TIRADS, ATA guidelines) in patients with or without Hashimoto's thyroiditis (HT and non-HT groups). The study included 1188 nodules (HT: 358, non-HT: 830) with known final diagnoses. We found that the strongest indications of nodule's malignancy were microcalcifications (OR: 22.7) in HT group and irregular margins (OR:13.8) in non-HT group. Solid echostructure and macrocalcifications were ineffective in patients with HT. The highest accuracy of nodule's shape criterion was noted on transverse section, with the cut-off value of anteroposterior to transverse dimension ratio (AP/T) close to 1.15 in both groups. When round nodules were regarded as suspicious in patients with HT (the cut-off value of AP/T set to ≥1), it led to a three-fold increase in sensitivity of this feature, with a disproportionally lower decrease in specificity and similar accuracy. Such a modification was effective also for cancers other than PTC. The diagnostic effectiveness of analyzed TIRADS in patients with HT and without HT was similar. Changes in the threshold for AP/T ratio influenced the number of nodules classified into the category of the highest risk, especially in the case of EU-TIRADS.

Comparison of Korean vs. American Thyroid Imaging Reporting and Data System in Malignancy Risk Assessment of Indeterminate Thyroid Nodules.

BACKGROUND: The management of cytologically indeterminate thyroid nodules is challenging for clinicians. This study aimed to compare the diagnostic performance of the Korean Thyroid Imaging Reporting and Data Systems (K-TIRADS) with that of the American College of Radiology (ACR)-TIRADS for predicting the malignancy risk of indeterminate thyroid nodules. METHODS: Thyroid nodules diagnosed by fine-needle aspiration (FNA) followed by surgery or core needle biopsy at a single referral hospital were enrolled. RESULTS: Among 200 thyroid nodules, 78 (39.0%) nodules were classified as indeterminate by FNA (Bethesda category III, IV, and V), and 114 (57.0%) nodules were finally diagnosed as malignancy by surgery or core needle biopsy. The area under the curve (AUC) was higher for FNA than for either TIRADS system in all nodules, while all three methods showed similar AUCs for indeterminate nodules. However, for Bethesda category III nodules, applying K-TIRADS 5 significantly increased the risk of malignancy compared to a cytological examination alone (50.0% vs. 26.5%, P=0.028), whereas applying ACR-TIRADS did not lead to a change. CONCLUSION: K-TIRADS and ACR-TIRADS showed similar diagnostic performance in assessing indeterminate thyroid nodules, and K-TIRADS had beneficial effects for malignancy prediction in Bethesda category III nodules.

Diagnostic Performance of Kwak, EU, ACR, and Korean TIRADS as Well as ATA Guidelines for the Ultrasound Risk Stratification of Non-Autonomously Functioning Thyroid Nodules in a Region with Long History of Iodine Deficiency: A German Multicenter Trial.

Germany has a long history of insufficient iodine supply and thyroid nodules occur in over 30% of the adult population, the vast majority of which are benign. Non-invasive diagnostics remain challenging, and ultrasound-based risk stratification systems are essential for selecting lesions requiring further clarification. However, no recommendation can yet be made about which system performs the best for iodine deficiency areas. In a German multicenter approach, 1211 thyroid nodules from 849 consecutive patients with cytological or histopathological results were enrolled. Scintigraphically hyperfunctioning lesions were excluded. Ultrasound features were prospectively recorded, and the resulting classifications according to five risk stratification systems were retrospectively determined. Observations determined 1022 benign and 189 malignant lesions. The diagnostic accuracies were 0.79, 0.78, 0.70, 0.82, and 0.79 for Kwak Thyroid Imaging Reporting and Data System (Kwak-TIRADS), American College of Radiology (ACR) TI-RADS, European Thyroid Association (EU)-TIRADS, Korean-TIRADS, and American Thyroid Association (ATA) Guidelines, respectively. Receiver Operating Curves revealed Areas under the Curve of 0.803, 0.795, 0.800, 0.805, and 0.801, respectively. According to the ATA Guidelines, 135 thyroid nodules (11.1%) could not be classified. Kwak-TIRADS, ACR TI-RADS, and Korean-TIRADS outperformed EU-TIRADS and ATA Guidelines and therefore can be primarily recommended for non-autonomously functioning lesions in areas with a history of iodine deficiency.

A retrospective study of reducing unnecessary thyroid biopsy for American College of Radiology Thyroid Imaging Reporting and Data Systems 4 assessment through applying shear wave elastography

ABSTRACT Objective The purpose of the study is to quantitatively assess shear-wave elastography (SWE) value in American College of Radiology Thyroid Imaging Reporting and Data Systems (ACR TI-RADS) 4. Materials and methods One hundred and fifty-two ACR TI-RADS 4 thyroid nodules undergoing SWE were included in the study. The mean (EMean), minimum (EMin) and maximum (EMax) of SWE elasticity were measured. Results The areas under the receiver operating characteristic (ROC) curves for SWE EMean, EMin and EMax in detecting benign and malignant nodules were 0.95, 0.83 and 0.84, respectively. Cut-off value of EMean ≤ 23.30 kPa is able to downgrade the lesion category to ACR TI-RADS 3 and cut-off value of EMean ≥ 52.14 kPa is able to upgrade the lesion category to ACR TI-RADS 5. Conclusions The EMean of SWE will probably identify nodules that have a high potential for benignity in ACR TI-RADS 4. It may help identify and select benign nodules while reducing unnecessary biopsy of benign thyroid nodules.

[Accuracy of two thyroid imaging, reporting and data systems for differential diagnosis of benign and malignant thyroid nodules].

OBJECTIVE: To compare the accuracy of two widely used thyroid imaging, reporting and data systems (TI-RADS), namely ACR TI-RADS and Kwak TI-RADS, in the differential diagnosis of benign and malignant thyroid nodules. METHODS: We reviewed the data of 350 thyroid nodules with definite diagnoses by surgical histopathology (n=144, 41.14%) or fine needle aspiration (FNA) cytopathology (n=206, 58.86%). The nodules were graded using ACR TI-RADS and Kwak TI-RADS based on the ultrasound images, and the diagnostic accuracy of these two systems was evaluated by the area under the receiveroperating characteristic curve (AUC). RESULTS: The AUCs of ACR TI-RADS and Kwak TI-RADS were both 0.879. For a differential diagnosis of the thyroid nodules, ACR TI-RADS had a diagnostic sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, Youden's index and accuracy of 77.3%, 89.1%, 83.0%, 85.1%, 7.101, 0.255, 27.848, 0.664 and 0.843, respectively, with an optimal threshold of TR5, as compared with 84.8%, 84.0%, 78.3%, 89.0%, 5.283, 0.181, 29.265, 0.688 and 0.843, respectively, of Kwak TI-RADS, which had an optimal threshold of 4c. CONCLUSIONS: Both ACR TI-RADS and Kwak TI-RADS have good performance for differential diagnosis of thyroid nodules, but ACR TI-RADS has a higher specificity and a lower sensitivity compared with Kwak TI-RADS.