Use of the Kwak Thyroid Image Reporting and Data System (K-TIRADS) in differential diagnosis of thyroid nodules: systematic review and meta-analysis

Comparison of diagnostic performance of two ultrasound risk stratification systems for thyroid nodules: a systematic review and meta-analysis

OBJECTIVES

To assume the ideal cut-off values and diagnostic performance of two thyroid imaging reporting and data systems published by the Korean Thyroid Association/Korean Society of Thyroid Radiology (Korean TI-RADS) and the American Thyroid Association (ATA TI-RADS).

METHODS

Eighteen studies with 25,422 patients from PubMed, SCOPUS, Embase, Web of Science, and Cochrane Library databases up to August 2022. True and false positive and negative values with characteristics were extracted.

RESULTS

The highest area under the receiver operating characteristic curve (AUC) was 0.893 and 0.887 for Korean and ATA TI-RADS. High suspicion was judged as the best cut-off value with the highest AUC based on optimal sensitivity and specificity. In determining the risk of malignant thyroid nodules, high suspicion in Korean and ATA TI-RADS showed sensitivity as 71.3% and 73.5%, specificity as 7.9% and 86.4%, diagnostic odds ratios as 20.0289 and 20.9076, AUC as 0.893 and 0.887. There was no significant difference when directly comparing the diagnostic accuracy of both TI-RADS.

CONCLUSION

The two risk stratification systems had good diagnostic performance with high AUC and no significant differences. The ideal cut-off can depend on the medical condition or thyroid nodules, because the changes of cut-off point may reciprocally alter sensitivity and specificity.

The auxiliary diagnosis of thyroid echogenic foci based on a deep learning segmentation model: A two-center study

OBJECTIVE

The aim of this study is to develop AI-assisted software incorporating a deep learning (DL) model based on static ultrasound images. The software aims to aid physicians in distinguishing between malignant and benign thyroid nodules with echogenic foci and to investigate how the AI-assisted DL model can enhance radiologists' diagnostic performance.

METHODS

For this retrospective study, a total of 2724 ultrasound (US) scans were collected from two independent institutions, encompassing 1038 echogenic foci nodules. All echogenic foci were confirmed by pathology. Three DL segmentation models (DeepLabV3+, U-Net, and PSPNet) were developed, with each model using two different backbones to extract features from the nodular regions with echogenic foci. Evaluation indexes such as Mean Intersection over Union (MIoU), Mean Pixel Accuracy (MPA), and Dice coefficients were employed to assess the performance of the segmentation model. The model demonstrating the best performance was selected to develop the AI-assisted diagnostic software, enabling radiologists to benefit from AI-assisted diagnosis. The diagnostic performance of radiologists with varying levels of seniority and beginner radiologists in assessing high-echo nodules was then compared, both with and without the use of auxiliary strategies. The area under the receiver operating characteristic curve (AUROC) was used as the primary evaluation index, both with and without the use of auxiliary strategies.

RESULTS

In the analysis of Institution 2, the DeepLabV3+ (backbone is MobileNetV2 exhibited optimal segmentation performance, with MIoU = 0.891, MPA = 0.945, and Dice = 0.919. The combined AUROC (0.693 [95% CI 0.595-0.791]) of radiology beginners using AI-assisted strategies was significantly higher than those without such strategies (0.551 [0.445-0.657]). Additionally, the combined AUROC of junior physicians employing adjuvant strategies improved from 0.674 [0.574-0.774] to 0.757 [0.666-0.848]. Similarly, the combined AUROC of senior physicians increased slightly, rising from 0.745 [0.652-0.838] to 0.813 [0.730-0.896]. With the implementation of AI-assisted strategies, the accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of both senior physicians and beginners in the radiology department underwent varying degrees of improvement.

CONCLUSIONS

This study demonstrates that the DL-based auxiliary diagnosis model using US static images can improve the performance of radiologists and radiology students in identifying thyroid echogenic foci.

Effect of the categorization method on the diagnostic performance of ultrasound risk stratification systems for thyroid nodules

Objective

To evaluate whether the categorization methods of risk stratification systems (RSSs) is a decisive factor that influenced the diagnostic performances and unnecessary FNA rates in order to choose optimal RSS for the management of thyroid nodules.

Methods

From July 2013 to January 2019, 2667 patients with 3944 thyroid nodules had undergone pathological diagnosis after thyroidectomy and/or US-guided FNA. US categories were assigned according to the six RSSs. The diagnostic performances and unnecessary FNA rates were calculated and compared according to the US-based final assessment categories and the unified size thresholds for biopsy proposed by ACR-TIRADS, respectively.

Results

A total of 1781 (45.2%) thyroid nodules were diagnosed as malignant after thyroidectomy or biopsy. Significantly lowest specificity and accuracy, along with the highest unnecessary FNA rates were seen in EU-TIRADS for both US categories (47.9%, 70.2%, and 39.4%, respectively, all P < 0.05) and indications for FNA (54.2%, 50.0%, and 55.4%, respectively, all P < 0.05). Diagnostic performances for US-based final assessment categories exhibited similar accuracy for AI-TIRADS, Kwak-TIRADS, C-TIRADS, and ATA guidelines (78.0%, 77.8%, 77.9%, and 76.3%, respectively, all P > 0.05), while the lowest unnecessary FNA rate was seen in C-TIRADS (30.9%) and without significant differences to that of AI-TIRADS, Kwak-TIRADS, and ATA guideline (31.5%, 31.7%, and 33.6%, respectively, all P > 0.05). Diagnostic performance for US-FNA indications showed similar accuracy for ACR-TIRADS, Kwak-TIRADS, C-TIRADS and ATA guidelines (58.0%, 59.7%, 58.7%, and 57.1%, respectively, all P > 0.05). The highest accuracy and lowest unnecessary FNA rate were seen in AI-TIRADS (61.9%, 38.6%) and without significant differences to that of Kwak-TIRADS(59.7%, 42.9%) and C-TIRADS 58.7%, 43.9%, all P > 0.05).

Conclusion

The different US categorization methods used by each RSS were not determinant influential factors in diagnostic performance and unnecessary FNA rate. For daily clinical practice, the score-based counting RSS was an optimal choice.

Prognostic Utility of Tumor Stage versus American Thyroid Association Risk Class in Thyroid Cancer

OBJECTIVE

To evaluate the prognostic strengths of American Joint Committee on Cancer (AJCC) staging and American Thyroid Association (ATA) risk classification in well-differentiated thyroid cancer (DTC), and their implications in guiding medical decision-making and epidemiological study designs.

METHODS

The 2004-2017 National Cancer Database was queried for DTC patients. Cox proportional hazards (CPH) and Kaplan-Meier analyses modeled patient mortality and overall survival, respectively. Each CPH model was evaluated by its concordance index, measure of explained randomness (MER), Akaike information criterion (AIC), and area under receiver operating characteristic curve (AUC).

RESULTS

Overall, 134,226 patients were analyzed, with an average age of 48.1 ± 15.1 years (76.9% female). Univariate CPH models using AJCC staging demonstrated higher concordance indices, MERs, and AUCs than those using ATA risk classification (all p < 0.001). Multivariable CPH models using AJCC staging demonstrated higher concordance indices (p = 0.049), MERs (p = 0.046), and AUCs (p = 0.002) than those using ATA risk classification. The AICs of multivariable AJCC staging and ATA risk models were 7.564 × 104 and 7.603 × 104 , respectively. AJCC stage I tumors were associated with greater overall survival than those classified as ATA low risk, whereas AJCC stages II-III and stage IV tumors demonstrated worse survival than ATA intermediate- and high-risk tumors, respectively (all p < 0.001).

CONCLUSION

AJCC staging may be a more predictive system for patient survival than ATA risk. The prognostic utility of these two systems converges when additional demographic and clinical factors are considered. AJCC staging was found to classify patients across a wider range of survival patterns than the ATA risk stratification system.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:205-211, 2023.

Diagnostic Performance of ACR and Kwak TI-RADS for Benign and Malignant Thyroid Nodules: An Update Systematic Review and Meta-Analysis

(1) Background: To determine the optimal cut-off values of two risk stratification systems to discriminate malignant thyroid nodules and to compare the diagnostic performance; (2) Methods: True and false positive and negative data were collected, and methodological quality was assessed for forty-six studies involving 39,085 patients; (3) Results: The highest area under the receiver operating characteristic (ROC) curve (AUC) of ACR and Kwak TI-RADS were 0.875 and 0.884. Based on the optimal sensitivity and specificity, the highest accuracy values of ROC curves or diagnostic odds ratios (DOR) were taken as the cut-off values for TR4 (moderate suspicious) and 4B. The sensitivity, specificity, DOR, and AUC by ACR (TR4) and Kwak TI-RADS (4B) for malignancy risk stratification of thyroid nodules were 94.3% and 96.4%; 52.2% and 53.7%; 17.5185 and 31.8051; 0.786 and 0.884, respectively. There were no significant differences in diagnostic accuracy in any of the direction comparisons of the two systems; (4) Conclusions: ACR and Kwak TI-RADS had good diagnostic performances (AUCs > 85%). Although we determined the best cut-off values in individual risk stratification systems based on statistical assessment, clinicians can adjust the optimal cut-off value according to the clinical purpose of the ultrasonography because raising or lowering cut-points leads to reciprocal changes in sensitivity and specificity.

The value of neutrophil‐to‐lymphocyte ratio combined with the thyroid imaging reporting and data system in the diagnosis of the nature of thyroid nodules

Objective

The aim of this study was to investigate the diagnostic value of peripheral blood neutrophil‐to‐lymphocyte ratio (NLR) combined with the thyroid imaging reporting and data system (TIRADS) for benign and malignant thyroid nodules.

Methods

A total of 585 adults were enrolled in the study. The receiver operating characteristic curves were used to determine the optimal cut‐off values for NLR and Kwak TIRADS (K‐TIRADS) grades, which were 1.87 and 4a, respectively. Thyroid nodules were scored as follows: NLR–K‐TIRADS score is 2 (both elevated K‐TIRADS grade and NLR), NLR–K‐TIRADS score is 1 (one of these was elevated) and NLR–k‐TIRADS score is 0 (neither were elevated).

Results

The proportions of malignant nodules with NLR‐K‐TIRADS scores of 2, 1 and 0 were 98.59%, 69.62% and 10.19%, and the difference was statistically significant (p < 0.001). In terms of the sensitivity of diagnosis of malignant nodules, NLR‐K‐TIRADS 1 tends to increase relative to K‐TIRADS grades ≥ 4a; in terms of specificity and positive predictive value for the diagnosis of malignant nodules, NLR–K‐TIRADS 2 was significantly higher than K‐TIRADS grades ≥ 4a (all p < 0.05).

Conclusions

NLR combined with K‐TIRADS grades may be a novel method for screening benign and malignant thyroid nodules.

Diagnostic Reliability of the American College of Radiology Thyroid Imaging Reporting and Data System in Royal Commission Hospital, Kingdom of Saudi Arabia

BACKGROUND: The American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) classified and predicted the risk of thyroid nodule malignancy with ultrasound scan scoring system. AIM: Hence, we aimed to investigate the value of the combined use of ultrasound ACR TI-RADS scoring and ultrasound-guided thyroid fine needle aspiration cytology (FNAC) based on the Bethesda System for Reporting Thyroid Cytology (TBSRTC) for assessing the accuracy tests of diagnosing low and high-risk thyroid nodules of ACR TI-RADS. METHODS: We enrolled 392 patients with thyroid nodules who underwent ultrasound scanning and scoring using the ACR TI-RADS classification along with ultrasound-guided thyroid FNAC and scoring with TBSRTC. The two methods were grouped as low and high risk of malignancy to evaluate the accuracy of ACR TI-RADS. RESULTS: Three hundred and ninety-two patients were enrolled in the study. The mean (Standard deviation [SD]) age was 46.03 (13.96) years, 332 (84.7%) were females and the mean (SD) of body mass index was 31.90 (22.32) kg/m2 and Vitamin D 17.65 (11.15) nmol/L. The mean (SD) for thyroid function test was 5.37 (44.16) mmol/L for thyroid-stimulating hormone, 1.48 (1.49) ng/dL for free thyroxine (FT4), and 2.69 (0.70) nmol/L for free triiodothyronine (FT3). Most of the participants were euthyroid (63.8%), but 28.6% had hypothyroidism and 7.7% had hyperthyroidism. The accuracy tests of ACR TI-RADS in relation to TBSRTC, were sensitivity (87.8%), specificity (65.2%), positive predictive value (29.8%), and negative predictive value (97%). The area under the curve = 0.590, 95% CI = 0.530–0.650, p ˂ 0.006. CONCLUSION: ACR TI-RADS is a simple, practical, and reliable scoring system for assessing thyroid nodule; it has a better overall diagnostic performance and the ability to exclude unnecessary FNAC with high negative predictive value.

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 Simplified Ultrasonographic Score for the Prediction of Cytologically Suspicious Thyroid Nodules

PURPOSE

 The major aim of ultrasound (US)-based risk stratification systems is to reduce unnecessary thyroid biopsies without losing the ability to recognize nodules with clinically significant malignancy. Each of the classic suspicious features of a thyroid nodule detected on US scan (hypoechoic pattern, microcalcifications, irregular margin, taller than wide shape, irregular vascularization) is significantly independently associated with the probability of malignancy, but none of them has good diagnostic accuracy. Thus, we evaluated the predictive value of a binary score simply based on the combination of these US features, regardless of the specific predictive value of each US feature, against the outcome of suspected malignancy at cytological diagnosis (TIR3 to TIR5 categories by SIAPEC-IAP [TIR+]).

MATERIALS AND METHODS

 1009 thyroid nodules from 1081 patients were considered. The US features of suspicion of all nodules were categorized in 5 binary scores (U1 to U5), each including from 1 to 5 of those features.

RESULTS

 U2 (at least 2 US suspicious features) was the most balanced predictor of TIR+ (PPV 0.48, NPV 0.93, LR+ 3.05 and LR- 0.24). Weighting the predictivity of the single features did not improve the estimate. Using U2 as the criterion to send nodules to FNAC would have reduced the number of biopsies by 60 % (604 patients) and the false negatives would have only accounted for 41 cases out of 237 TIR+ (17 %) with 39 cases of TIR3 and 2 cases of TIR4, including only 6 malignant nodules on histological examination. U2 performed much better than the ATA recommendations for detecting those nodules, resulting in TIR+ at cytology.

CONCLUSION

 This simple and reproducible sonographic score based on 2 US features of suspicion of malignancy has quite a good performance with respect to identifying thyroid lesions categorized by cytology as medium-high risk of malignancy and could allow us to reduce cytology costs for low-risk nodules.

The impact of TI-RADS in detecting thyroid malignancies: a prospective study

INTRODUCTION

Thyroid ultrasonography (US) is the first-step noninvasive and easily accessible diagnostic method widely used in the detection and characterization of nodular thyroid disease. We aimed to develop a TI-RADS, which is easy to apply and only relies on the counting of suspicious criteria. In order to measure the reliability of the system, we investigated its correlation with fine needle aspiration biopsy (FNAB) and post-surgery histological results.

MATERIALS AND METHODS

In this prospective study, 242 patients who had undergone FNAB with simultaneous cytopathologist in the radiology department between April and August 2016 were analyzed. Before FNAB, the thyroid gland was re-evaluated with US, and TI-RADS classification was made. Demographic characteristics, family thyroid cancer history and radiotherapy history to the neck region were noted.

RESULTS

Of the 242 patients, 17.3% were male (42 males/200 females). US-guided FNAB was applied to all patients. Mean age was 50 ± 13 years (min: 19, max: 82). Both FNAB and final post-surgery histology results showed that sex and age were not statistically significantly associated with malignancy (p = 0.193) TI-RADS criteria and FNAB results revealed a statistically significant association between irregular contours, the state of anteroposterior diameter being longer than transverse diameter, microcalcifications, marked hypoechogenicity, and malignancy (p < 0,05). Thirty patients were TI-RADS ≥ 4, 206 patients were TI-RADS ≤ 3 and there was a significant correlation between TI-RADS and Bethesda classification (p = 0.001). In addition, statistically significant associations were found between malignancy and family history of thyroid cancer (p = 0.035) and radiotherapy history to the neck region (p = 0.01).

CONCLUSION

TI-RADS system after nodule identification is based only on the counting of suspicious criteria. It will be safe and effective to recommend follow-up with low score TI-RADS, benign characters and insufficient FNAB results, and thus, unnecessary thyroidectomy operations will be prevented. It will be easier for surgeons to recommend surgery and persuade the patients for it when patients have high TI-RADS scores. TI-RADS has high power in detecting malignancy by recommending biopsy of suspicious nodules.

Comparison of diagnostic performance of the ACR and Kwak TIRADS applying the ACR TIRADS' size thresholds for FNA

OBJECTIVE

To investigate the diagnostic performances and unnecessary fine-needle aspiration (FNA) rates of two point-scale based TIRADS and compare them with a modified version using the ACR TIRADS' size thresholds.

METHODS

Our Institutional Review Board approved this retrospective study and waived the requirement for informed consent. A total of 2106 thyroid nodules 10 mm or larger in size in 2084 patients with definitive cytopathologic findings were included. Ultrasonography categories were assigned according to each guideline. We applied the ACR TIRADS' size thresholds for FNA to the Kwak TIRADS and defined it as the modified Kwak TIRADS (mKwak TIRADS). Diagnostic performances and unnecessary FNA rates were evaluated for both the original and modified guidelines.

RESULTS

Of the original guidelines, the ACR TIRADS had higher specificity, accuracy, and area under the receiver operating characteristic curve (AUC) (63.1%, 68.9%, and 0.748, respectively). When the size threshold of the ACR TIRADS was applied to the Kwak TIRADS, the resultant mKwak TIRADS had higher specificity, accuracy, and AUC (64.7%, 70.3%, and 0.765, respectively) than the ACR TIRADS. The mKwak TIRADS also had a lower unnecessary FNA rate than the ACR TIRADS (54.8% and 56.4%, respectively). The false-negative rate of the Kwak TIRADS was the lowest (1.9%) among all TIRADS.

CONCLUSION

The modified Kwak TIRADS incorporating the size thresholds of the ACR TIRADS showed higher diagnostic performance and a lower unnecessary FNA rate than the original point-scale based TIRADS.

KEY POINTS

• Of the original guidelines, the ACR TIRADS had the highest specificity, accuracy, and area under the receiver operating characteristic curve (AUC) (63.1%, 68.9%, and 0.748, respectively). • When the size threshold of the ACR TIRADS was applied to the Kwak TIRADS, the resultant modified version of Kwak TIRADS had higher specificity, accuracy, and AUC (64.7%, 70.3%, and 0.765, respectively) than the ACR TIRADS. • The false-negative rate of the Kwak TIRADS was the lowest (1.9%) among all TIRADS.

Diagnostic Performance of American College of Radiology TI-RADS: A Systematic Review and Meta-Analysis

OBJECTIVE. The objective of our study was to investigate the diagnostic performance of the American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) in the risk stratification of thyroid nodules. MATERIALS AND METHODS. A literature search of MEDLINE, Embase, Cochrane Library, Web of Science, and Google Scholar was performed for articles published before July 31, 2019. We included studies using ACR TI-RADS for stratification of thyroid nodules and cytology results from ultrasound-guided fine-needle aspiration biopsy (FNAB), pathology results from surgical resection of the thyroid, or both FNAB cytology and surgical pathology results as the reference standard. Summary estimates of sensitivity and specificity were calculated with the bivariate random-effects modeling and are visually presented in forest plots. We performed multiple subgroup analyses and meta-regression to explore the effects of various clinical settings. We compared ACR TI-RADS with the American Thyroid Association (ATA) guidelines and Korean Thyroid Imaging Reporting and Data System (TIRADS) in studies providing head-to-head comparison. RESULTS. Sixteen studies with 18,614 patients involving a total of 21,882 nodules, were included. The pooled sensitivity and specificity of ACR TI-RADS were 0.89 (95% CI, 0.81-0.93) and 0.70 (95% CI, 0.60-0.78), respectively. The calculated area under summary ROC curve was 0.86 (95% CI, 0.83-0.89), with a diagnostic odds ratio of 18.46 (95% CI, 9.77-34.88). Meta-regression revealed that patient number was a significant factor for heterogeneity (p = 0.02). Ten studies compared the performance of ACR TI-RADS and ATA guidelines: The pooled sensitivity was 0.83 versus 0.87 (p = 0.5), respectively, and the pooled specificity was 0.69 versus 0.50 (p = 0.1). In six studies providing direct comparison of ACR TI-RADS and Korean TIRADS, the pooled sensitivity was 0.85 versus 0.91 (p = 0.13), and the pooled specificity was 0.57 versus 0.24 (p < 0.001). CONCLUSION. ACR TI-RADS showed favorable sensitivity and moderate specificity in risk stratification of thyroid nodules. The use of ACR TI-RADS could avoid a large number of unnecessary biopsies, although at the cost of a slight decline in sensitivity.

S-Detect Software vs. EU-TIRADS Classification: A Dual-Center Validation of Diagnostic Performance in Differentiation of Thyroid Nodules

Computer-aided diagnosis (CAD) and other risk stratification systems may improve ultrasound image interpretation. This prospective study aimed to compare the diagnostic performance of CAD and the European Thyroid Imaging Reporting and Data System (EU-TIRADS) classification applied by physicians with S-Detect 2 software CAD based on Korean Thyroid Imaging Reporting and Data System (K-TIRADS) and combinations of both methods (MODELs 1 to 5). In all, 133 nodules from 88 patients referred to thyroidectomy with available histopathology or with unambiguous results of cytology were included. The S-Detect system, EU-TIRADS, and mixed MODELs 1–5 for the diagnosis of thyroid cancer showed a sensitivity of 89.4%, 90.9%, 84.9%, 95.5%, 93.9%, 78.9% and 93.9%; a specificity of 80.6%, 61.2%, 88.1%, 53.7%, 73.1%, 89.6% and 80.6%; a positive predictive value of 81.9%, 69.8%, 87.5%, 67%, 77.5%, 88.1% and 82.7%; a negative predictive value of 88.5%, 87.2%, 85.5%, 92.3%, 92.5%, 81.1% and 93.1%; and an accuracy of 85%, 75.9%, 86.5%, 74.4%, 83.5%, 84.2%, and 87.2%, respectively. Comparison showed superiority of the similar MODELs 1 and 5 over other mixed models as well as EU-TIRADS and S-Detect used alone (p-value < 0.05). S-Detect software is characterized with high sensitivity and good specificity, whereas EU-TIRADS has high sensitivity, but rather low specificity. The best diagnostic performance in malignant thyroid nodule (TN) risk stratification was obtained for the combined model of S-Detect (“possibly malignant” nodule) and simultaneously obtaining 4 or 5 points (MODEL 1) or exactly 5 points (MODEL 5) on the EU-TIRADS scale.

COMPARISON OF DIAGNOSTIC PERFORMANCE BETWEEN THE AMERICAN COLLEGE OF RADIOLOGY THYROID IMAGING REPORTING AND DATA SYSTEM AND AMERICAN THYROID ASSOCIATION GUIDELINES: A SYSTEMATIC REVIEW

Objective: We aimed to compare the diagnostic accuracy of the American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) with the American Thyroid Association (ATA) guidelines in risk stratification of thyroid nodules. Methods: We performed a computerized search of Medline, EMBASE, Web of Science, Cochrane Library, and Google Scholar to identify eligible articles published before July 31, 2019. We included studies providing head-to-head comparison between ACR TI-RADS and ATA guidelines, with fine-needle aspiration biopsy cytology results or pathology results as the reference standard. Quality assessment of included studies was conducted using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Summary estimates of sensitivity and specificity were calculated by bivariate modeling and hierarchical summary receiver operating characteristic modeling. We also performed multiple subgroup analyses and meta-regression. Results: Twelve original articles with 13,000 patients were included, involving a total of 14,867 thyroid nodules. The pooled sensitivity of ACR TI-RADS and ATA guidelines was 0.84 (95% confidence interval [CI], 0.76-0.89) and 0.89 (95% CI, 0.80-0.95), with specificity of 0.67 (95% CI, 0.56-0.76) and 0.46 (95% CI, 0.29-0.63), respectively. There were no significant differences between the two classification criteria in terms of both sensitivity (P = .26) and specificity (P = .05). For five studies providing direct comparison of ACR TI-RADS, ATA guidelines, and Korean TI-RADS, our analyses showed that the Korean TI-RADS yielded the highest sensitivity (0.89; 95% CI, 0.82-0.94), but at the cost of a significant decline in specificity (0.23; 95% CI, 0.17-0.30). Conclusion: Both classification criteria demonstrated favorable sensitivity and moderate specificity in the stratification of thyroid nodules. However, use of ACR TI-RADS could avoid a large number of biopsies at the cost of only a slight decrease in sensitivity. Abbreviations: ACR = American College of Radiology; ATA = American Thyroid Association; FNAB = fine-needle aspiration biopsy; HSROC = hierarchical summary receiver operating characteristic; SROC = summary receiver operating characteristic; TI-RADS = Thyroid Imaging Reporting and Data System; US = ultrasonography.

Discriminating Malignancy in Thyroid Nodules: The Nomogram Versus the Kwak and ACR TI-RADS

OBJECTIVE

To develop an easy-to-use nomogram for discrimination of malignant thyroid nodules and to compare diagnostic efficiency with the Kwak and American College of Radiology (ACR) Thyroid Imaging, Reporting and Data System (TI-RADS).

STUDY DESIGN

Retrospective diagnostic study.

SETTING

The Second Hospital of Shandong University.

SUBJECTS AND METHODS

From March 2017 to April 2019, 792 patients with 1940 thyroid nodules were included into the training set; from May 2019 to December 2019, 174 patients with 389 nodules were included into the validation set. Multivariable logistic regression model was used to develop a nomogram for discriminating malignant nodules. To compare the diagnostic performance of the nomogram with the Kwak and ACR TI-RADS, the area under the receiver operating characteristic curve, sensitivity, specificity, and positive and negative predictive values were calculated.

RESULTS

The nomogram consisted of 7 factors: composition, orientation, echogenicity, border, margin, extrathyroidal extension, and calcification. In the training set, for all nodules, the area under the curve (AUC) for the nomogram was 0.844, which was higher than the Kwak TI-RADS (0.826, P = .008) and the ACR TI-RADS (0.810, P < .001). For the 822 nodules >1 cm, the AUC of the nomogram was 0.891, which was higher than the Kwak TI-RADS (0.852, P < .001) and the ACR TI-RADS (0.853, P < .001). In the validation set, the AUC of the nomogram was also higher than the Kwak and ACR TI-RADS (P < .05), each in the whole series and separately for nodules >1 or ≤1 cm.

CONCLUSIONS

When compared with the Kwak and ACR TI-RADS, the nomogram had a better performance in discriminating malignant thyroid nodules.

Diagnostic performances and unnecessary US-FNA rates of various TIRADS after application of equal size thresholds

We compared the diagnostic performances and unnecessary FNA rates of several guidelines and modified versions using the size threshold of the ACR TIRADS. Our Institutional Review Board approved this retrospective study and waived the requirement for informed consent and all methods were performed in accordance with the Declaration of Helsinki. A total of 1,384 thyroid nodules in 1,301 patients with definitive cytopathologic findings were included. US categories were assigned according to each guideline. We applied the size threshold suggested by the ACR TIRADS for FNA to the Kwak, ATA and EU guidelines and defined these modified guidelines as the modified Kwak (mKwak), modified ATA (mATA) and modified EU (mEU) guidelines. Diagnostic performances and unnecessary FNA rates of all guidelines were evaluated. Of 1,384 thyroid nodules, 291 (21%) were malignant. Among the original guidelines, the ACR TIRADS had the highest specificity, accuracy, LR and AUC (62.2%, 66%, 2.128 and 0.713). The mKwak, mATA and mEU guidelines had higher specificity, accuracy, LR and AUC (P < 0.001 for all), and fewer unnecessary FNAs, compared with their original guidelines. Among all original and modified guidelines, the mKwak guideline had the highest specificity, accuracy, LR and AUC (64%, 68.6%, 2.389 and 0.75). The unnecessary FNA rate was the lowest with the mKwak guideline (61.1%). The highest sensitivity was observed with the ATA guideline (98.6%). After incorporating the size threshold of the ACR TIRADS to other TIRADS, all guidelines showed higher diagnostic accuracy and lower unnecessary FNA rates than their original versions. The mKwak guideline showed the best diagnostic performances.

Feasibility of Thyroid Imaging Reporting and Data System Classification in Predicting Thyroid Malignancy

In this study, we aimed to evaluate the diagnostic value of thyroid imaging reporting and data system (TIRADS) in the estimation of malignancy and assess the concordance between TIRADS and the histopathology results of the postoperative specimens. Consecutive ultrasound imaging records of patients with multinodular goiter from January 2010 to December 2017 who underwent surgery were retrospectively reviewed. The risk of malignancy of each TIRADS category was determined, and correlation with pathology was assessed. The patients with malignant cytology findings (Bethesda 6) who were categorized TIRADS 6 were excluded from the study. The positive and negative predictive values, sensitivity, specificity, and accuracy of the TIRADS classification were calculated on a 2 x 2 table with their own formulas. A total of 1457 patients were evaluated, and 1122 of these were included in the study. The risk of malignancy for nodules evaluated as TIRADS 2 was 0.6 per cent, TIRADS 3 was 13.1 per cent, TIRADS 4a was 20 per cent, TIRADS 4b was 61.1 per cent, TIRADS 4c was 85.7 per cent, and TIRADS 5 was 93.3 per cent. The positive predictive value of TIRADS classification was found to be 43.4 per cent, negative predictive value was found to be 90.7 per cent, sensitivity was found to be 78 per cent, specificity was found to be 68.4 per cent, and accuracy was found to be 70.7 per cent for our institution. The TIRADS classification based on suspicious ultrasound findings is reliable in predicting thyroid malignancy and can be routinely used in daily practice.

Incremental diagnostic value of shear wave elastography combined with contrast-enhanced ultrasound in TI-RADS category 4a and 4b nodules

PURPOSE

To evaluate the diagnostic value of shear wave elastography (SWE) combined with contrast-enhanced ultrasonography (CEUS) in diagnosing thyroid imaging reporting and data system (TI-RADS) category 4a and 4b nodules.

METHODS

TI-RADS, SWE, and CEUS features of 71 thyroid nodules (23 benign, 48 malignant) confirmed by postoperative pathological results were retrospectively analyzed. The diagnostic efficiency of each single method and that of a combination of three methods were compared.

RESULTS

The sensitivity and specificity in diagnosing thyroid nodules were 70.83% and 65.22% for TI-RADS, 68.75% and 91.30% for SWE, 77.08% and 78.26% for CEUS, and 91.67% and 95.65% for TI-RADS + SWE + CEUS, respectively. The area under the curve for TI-RADS, SWE, CEUS, and TI-RADS + SWE + CEUS in diagnosing thyroid nodules were 0.680, 0.839, 0.799, and 0.937, respectively. A significant difference was observed between a combination of the three methods and any of them alone (p < 0.05).

CONCLUSION

Combining SWE and CEUS improves the differential diagnosis of TI-RADS category 4a and 4b 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.

The Usefulness of the Thyroid Imaging Reporting and Data System in Determining Thyroid Malignancy

OBJECTIVES/HYPOTHESIS

To determine the effect of a modified Thyroid Imaging and Reporting Data System (TIRADS) in predicting malignancy in surgically treated nodules.

STUDY DESIGN

Retrospective review.

METHODS

This study was carried out at a tertiary care center from July 2016 to July 2017. Patients were included if they had a thyroid nodule that had an ultrasound assessment with subsequent fine-needle aspiration biopsy (FNAB) as well as surgical resection. Patients were excluded if they had previous head and neck surgery. Patients were stratified into those who had a formal modified TIRADS report by the radiologist versus those who had an ultrasound report without TIRADS reporting. FNAB results were reported as per Bethesda Thyroid Cytology Criteria, and the final pathology report was nominalized as malignant or benign.

RESULTS

One hundred twenty-four consecutive patients who met the inclusion criteria listed above were included within the study. Thirty one patients (25%) had a modified TIRADS report from the radiologist, whereas 93 patients (75%) did not. There was no statistical significance between the two groups in terms of: gender (P = .24), age (P = .77), FNAB results (P = .95), final surgical pathology (P = .90), or incidental findings of malignancy (P = .09). Comparative analysis showed no statistically significant difference between the two groups in terms of the concordance of FNAB and a final pathological diagnosis of malignancy (P = .91).

CONCLUSIONS

Despite the known diagnostic utility of the TIRADS in relation to FNAB results and its widespread use, this study shows that the overall detection of malignancy is not statistically different in those who received a modified TIRADS report.

LEVEL OF EVIDENCE

3 Laryngoscope, 130: 2087-2091, 2020.

Clinical Value of a Computer-Aided Diagnosis System in Thyroid Nodules: Analysis of a Reading Map Competition

We evaluated the accuracy of human and computer-aided diagnosis (CAD) in a reading map diagnosis competition for detection of thyroid cancers via ultrasonography (US). The competition comprised 33 thyroid nodule images randomly chosen between 2015 and 2017. One hundred seventy-seven contestants including one operator using CAD participated in the competition. The competition was separated into an online part and a live part. We compared the average accuracy of contestants and CAD in the detection of thyroid cancers. The accuracy of contestants and the CAD system was 60.3% and 84.8%, respectively. The accuracy of the CAD system was higher than that of the contestants with different technical titles. The areas under the curve for CAD and contestants were 0.985 (0.881-1.00) and 0.659 (0.645-0.673) (Z = 7.55, p < 0.01). The CAD system had high accuracy in this thyroid nodule reading map competition, and may be an adjuvant tool for radiologists.

Prospective analysis of inter-observer and intra-observer variability in multi ultrasound descriptor assessment of thyroid nodules

Aim: The aim of this study was to evaluate the inter- and intra-observer variability and accuracy of ultrasound assessment of thyroid nodules using a descriptive lexicon. Materials and methods: A prospective study was performed on complete ultrasound examinations, including sonoelastography and color Doppler ultrasound of 18 patients with 20 thyroid nodules. A total of 20 records of thyroid nodules from these techniques were duplicated, numbered, and randomly arranged. Five radiologists assessed the recordings independently. Cohen Kappa and Fleiss Kappa statistics were used to determine the degree of intra- and inter-observer agreement. Results: Mean accuracy rates for all radiologists, for all ultrasound features, ranged from 82.7 to 87.8%. For B-mode and strain elastography, accuracies ranged from 65.0 to 100% and 47.4 to 86.8%, respectively. Concerning intra-observer variability, three radiologists demonstrated almost perfect agreement (the κ-value ranged from 0.81 to 0.86), and a substantial agreement was noted for the two remaining radiologists. The κ-values for inter-observer agreement ranged from 0.61 for macrocalcifications (substantial agreement) to 0.33 for Asteria four-point elastography scale criteria (fair agreement). Conclusions: The results suggest relatively good inter-observer and excellent intra-observer agreement in the assessment of thyroid nodules using ultrasound, and fair agreement in the case of strain elastography.

British Thyroid Association 2014 classification ultrasound scoring of thyroid nodules in predicting malignancy: Diagnostic performance and inter-observer agreement

Objectives

To assess the inter-observer agreement amongst five observers of differing levels of expertise in applying the British Thyroid Association (2014) guidelines for ultrasound scoring of thyroid nodules (BTA-U score) in the management of thyroid cancer, and to assess the U-score diagnostic performance in predicting malignancy.

Method

A total of 73 consecutive patients were included over a two-year period (July 2012 to July 2014), after referral to a tertiary head and neck oncology centre for ultrasound plus fine needle aspiration and cytology. Our five observers retrospectively and independently reviewed static ultrasound images on PACS and scored the thyroid nodules according to BTA-U classification. The observers were blinded to each other's scoring, cytology and histology results. Either the Kappa-statistic or intra-class correlation was used to assess the level of inter-observer agreement, plus agreement between the radiological and cytological diagnoses. The diagnostic performance of U-scoring for predicting final histological diagnosis was assessed with sensitivity, specificity, positive and negative predictive values.

Results

A Kappa-value of 0.73 (95% CI: 0.68-0.77) confirmed substantial inter-observer agreement amongst the five observers. All 17 histology confirmed malignant nodules were correctly classified as potentially malignant by all observers. The sensitivity and negative predictive value of BTA-U score in detecting and predicting malignancy were 100%, whereas the specificity and positive predictive values were 34% and 32%, respectively.

Conclusions

There is good inter-observer agreement in using the BTA-U score amongst different observers at differing levels of expertise. Adhering to BTA-U scoring can potentially achieve 100% sensitivity in selecting malignant nodules for sampling.

Mummified Thyroid Nodules: Conventional and Contrast-Enhanced Ultrasound Features

OBJECTIVES

The purpose of our study was to highlight the conventional and contrast-enhanced ultrasound (US) features of mummified thyroid nodules, which should help differentiate them from histologically proven papillary thyroid carcinomas (PTCs).

METHODS

Thirty-one patients with 33 mummified thyroid nodules, which showed suspicious US findings that were suggestive of malignancy, as well as 33 patients with 38 surgically confirmed PTCs were enrolled in this study. We evaluated the size, shape, margin, echogenicity, presence of shadowing and halo, presence of punctate echogenic foci, vascularity, and contrast enhancement parameters for each nodule. The final diagnosis of mummified thyroid nodules was confirmed via fine-needle aspiration (FNA) or surgery.

RESULTS

Of the 33 mummified thyroid nodules, 9 (27.3%) were confirmed by surgery to be benign, and 24 (72.7%) were proven by FNA to be benign. A univariate analysis indicated that the mummified thyroid nodules more frequently showed wider-than-tall shapes, marked hypoechogenicity, the presence of posterior shadowing, the absence of nodular vascularity, hypoenhancement or no enhancement, and peak index and area under the curve indices of less than 1 in the findings of preoperative US and contrast-enhanced US compared to PTCs. A multivariate analysis showed that marked hypoechogenicity and an area under the curve index of less than 1 were independent characteristics related to mummified nodules for discriminating from PTCs (all P < .05).

CONCLUSIONS

Benign thyroid nodules may display shrinkage over time and may reveal malignant US features. Awareness of these findings and their connection with initial and follow-up US examinations should help identify mummified thyroid nodules and to avoid surgical excision or unnecessary FNA.

Accuracy of the European Thyroid Imaging Reporting and Data System (EU-TIRADS) in the valuation of thyroid nodule malignancy in reference to the post-surgery histological results

Purpose

To assess the clinical usefulness of the European Thyroid Imaging and Reporting Data System (EU-TIRADS) in the valuation of thyroid nodules malignancy in reference to post-surgery histological results.

Material and methods

Pre-operative ultrasound was performed in consecutive patients admitted for thyroid surgery between June 2017 and January 2018. Thyroid nodules were classified according to EU-TIRADS to five groups: 1-5. At least one fine-needle aspiration biopsy (FNAB)/patient (dominant or suspected nodule) was performed in an outpatient clinic. The final diagnosis was based on the histological result. The percentage of cancers in each EU-TIRADS group was evaluated. Finally, sensitivity, specificity, accuracy, as well as positive and negative predictive values for malignancy were assessed.

Results

Fifty-two patients with a total of 140 thyroid nodules (median: 3 nodules/thyroid [minimum-maximum: 1-6]) were enrolled in the study. Thyroid cancer was diagnosed in 0% (0/6) in EU-TIRADS 2; 0% (0/92) in EU-TIRADS 3; 5.9% (2/34) in EU-TIRADS 4, and 75% (6/8) in EU-TIRADS 5. In nodules assessed as EU-TIRADS ≥ 4 sensitivity, specificity, positive and negative predictive values for malignancy were, respectively: 75% (CI 95%: 40.7-93.5), 94.1% (CI 95%: 86.0-98.5), 75% (CI 95%: 40.7-93.5), and 94.1% (CI 95%: 86.0-98.5).

Conclusions

EU-TIRADS is a valuable and simple tool for assessment of the risk of malignancy of thyroid nodules and demonstrates a high ultrasound correlation with histological post-surgery results. FNAB should be performed in all nodules assessed as EU-TIRADS ≥ 4, due to higher risk of malignancy.