The New Era of TIRADSs to Stratify the Risk of Malignancy of Thyroid Nodules: Strengths, Weaknesses and Pitfalls

Performance of ACR-TIRADS in assessing thyroid nodules does not vary according to patient age

AIMS

A few studies have evaluated the performance of the American College of Radiology Thyroid Imaging Reporting And Data System (ACR-TIRADS) in pediatric and elderly patients and found differences between the latter two age groups and middle adulthood. Thus, the present study was undertaken to explore the possible variation of ACR-TIRADS performance across different ages of patients.

METHODS

A retrospective population undergoing thyroidectomy was selected to use histology as the reference standard. Ultrasound images were reviewed, and alignment of ACR-TIRADS with the corresponding histological diagnosis was made afterwards. Results of the age groups were compared. The ACR-TIRADS diagnostic performance was calculated considering the assessment of nodules across risk categories (i.e., from TR1 to TR5), rate of unnecessary FNAC (UN-FNAC), and rate of necessary but non-performed FNAC (NNP-FNAC).

RESULTS

Overall, 114 patients with a total of 220 nodules (46 carcinomas) were included. The rate of UN-FNAC was 66.3%, being 93.1% in TR3, 82.1% in TR4, and 31.4% in TR5. There were 15 NNP-FNACs. No significant difference was observed between age groups in terms of sample size, nodule, cancer, and FNAC. The nodule assessment according to ACR-TIRADS categories did not vary across ages. Sensitivity and specificity recorded in three age tertiles were not significantly different.

CONCLUSIONS

The present study shows that the performance of ACR-TIRADS is not significantly influenced by patient age.

Combining TSH measurement with TIRADS assessment to further improve the detection of thyroid cancers

BACKGROUND

Thyroid Imaging Reporting and Data Systems (TIRADSs) have demonstrated high performance in risk stratification of thyroid nodules (TNs). However, further improvements are needed in view of the ongoing project of an international TIRADS. Even if thyroid-stimulating hormone (TSH) measurement is traditionally used to assess the thyroid function, several papers have reported that higher TSH levels are associated with the presence of differentiated thyroid carcinoma (DTC). The present study aimed to investigate the role of TSH levels as improvement factor of American College of Radiology (ACR-), European Thyroid Association (EU-), and Korean Society (K-)TIRADS.

METHODS

Patients undergoing thyroidectomy were reviewed and TNs were re-assessed according to TIRADSs. Different TSH subgroups were attained. Histology was the reference standard. DTC risk of relapse was assessed according to American Thyroid Association guidelines.

RESULTS

The study series included 97 patients with 39.2% cancer prevalence. ACR-, EU-, and K-TIRADS indicated fine-needle aspiration cytology (FNAC) in 78.9%, 81.6%, and 92.1% of cases, respectively. All high-risk DTC had FNAC indication according to the three TIRADSs. The cancer rate was significantly lower in patients with TSH<0.4 mIU/L (P=0.04). The receiver operating characteristic (ROC) curve analysis showed that the best TSH cut-off to detect DTC patient was >1.3 mIU/L with Area Under the Curve (AUC)=0.70. Combining TSH data with TIRADS, the sensitivity of ACR-, EU-, and K-TIRADS increased to 92.1% 89.5%, and 94.7%, respectively. Conversely, the rate of unnecessary FNAC raised. At multivariate analysis, gender, TSH, and TIRADS were independent predictors of cancer.

CONCLUSIONS

Even if TIRADSs are strongly reliable to stratify the risk of malignancy of TNs, measuring TSH can further improve our sensitivity in detecting DTC.

Meaning of ACR-TIRADS recommendation in favor of follow-up rather than FNAC in thyroid nodules

Thyroid Imaging Reporting and Data Systems (TIRADSs) have been largely diffused for their high accuracy in risk stratification of thyroid nodules (TNs) and their selection for fine-needle aspiration cytology (FNAC). The most popular TIRADSs are ACR-, EU-, and K-TIRADS, with some discrepancies each other. One major difference is that ACR-TIRADS includes a recommendation in favor of follow-up in TNs having a major diameter insufficient to indicate FNAC. The present study aimed to explore prevalence and significance of this recommendation. EU- and K-TIRADS were used as comparator. A retrospective series of thyroidectomies was searched according to a pre-defined protocol. The study period was 2019-2023. Preoperative ultrasound images were reviewed by radiologists blinded of clinical data. Matching of TIRADS and histology was performed later. Histology was the gold standard. The study series included 39 TNs classified as category 3, 4, or 5 and assessed for follow-up according to ACR-TIRADS. The overall cancer frequency was 25.6%, being 13% in category 3, 20% in category 4, and 83.3% in category 5. The category assessment according to ACR-, EU-, and K-TIRADS was not significantly different. EU-TIRADS indicated FNAC in 10 TNs of which two cancers and eight benign lesions. K-TIRADS recommended FNAC in 32 TNs of which seven cancers and 25 benign lesions. TNs assessed for follow-up according to ACR-TIRADS are cancer in one-fourth of cases. EU- and, especially, K-TIRADS allow us to select for FNAC cancers, with the burden of non-negligible frequency of unnecessary FNACs.

Head-to-head comparison of American, European, and Asian TIRADSs in thyroid nodule assessment: systematic review and meta-analysis

Context

Ultrasound-based risk stratification systems (Thyroid Imaging Reporting and Data Systems (TIRADSs)) of thyroid nodules (TNs) have been implemented in clinical practice worldwide based on their high performance. However, it remains unexplored whether different TIRADSs perform uniformly across a range of TNs in routine practice. This issue is highly relevant today, given the ongoing international effort to establish a unified TIRADS (i.e. I-TIRADS), supported by the leading societies specializing in TNs. The study aimed to conduct a direct comparison among ACR-, EU-, and K-TIRADS in the distribution of TNs: (1) across the TIRADS categories, and (2) based on their estimated cancer risk.

Methods

A search was conducted on PubMed and Embase until June 2023. Original studies that sequentially assessed TNs using TIRADSs, regardless of FNAC indication, were selected. General study characteristics and data on the distribution of TNs across TIRADSs were extracted.

Results

Seven studies, reporting a total of 41,332 TNs, were included in the analysis. The prevalence of ACR-TIRADS 1-2 was significantly higher than that of EU-TIRADS 2 and K-TIRADS 2, with no significant difference observed among intermediate- and high-risk categories of TIRADSs. According to malignancy risk estimation, K-TIRADS often classified TNs as having more severe risk, ACR-TIRADS as having moderate risk, and EU-TIRADS classified TNs as having lower risk.

Conclusion

ACR-, EU-, and K-TIRADS assess TNs similarly across their categories, with slight differences in low-risk classifications. Despite this, focusing on cancer risk estimation, the three TIRADSs assess TNs differently. These findings should be considered as a prerequisite for developing the I-TIRADS.

Risk Factors and Prediction Models for Postoperative Pathologically Malignant TI-RADS 3 Thyroid Nodules

Objective: Our goal was to detect the risk factors for malignant TI-RADS 3 nodule and to construct a predictive model. Patients and Methods: All 199 patients with TI-RADS 3 nodule underwent first-time thyroid surgery from January 2018 to September 2021. Univariate analysis identified potential risk covariates and then incorporated these covariates into multivariate logistic regression to determine the risk factors for malignant TI-RADS 3 nodule and construct a predictive model. Results: Binary logistic regression analysis showed that age [odds ratio (OR): 0.926, 95% CI: 0.865-0.992; P = .029), low level of parathyroid hormone (OR: 0.940, 95% CI: 0.890-0.993; P = .027), and preoperative ultrasound features of TI-RADS 3 nodule, such as echogenicity (OR: 8.496, 95% CI: 1.377-52.406; P = .021), echogenic foci (OR: 8.611, 95% CI: 1.484-49.957; P = .016), and maximum tumor diameter (OR: 0.188, 95% CI: 0.040-0.888; P = .035) were independent risk factors for malignant TI-RADS 3 nodule. Based on these independent risk factors, a logistic regression model was established. The area under curve of the prediction model for TI-RADS 3 thyroid cancer was 0.921 (95% CI: 0.856-0.986, P < 0.001). The maximum Youden index was 0.698. The cut-off value, sensitivity, and specificity were 0.074, 84.6%, and 85.2%, respectively. Conclusion: Young age, iso/hypo/very hypo echo, echogenic foci, nodule diameter <30 mm, and low level of PTH are independent risk factors for TI-RADS 3 thyroid carcinomas. This prediction model has a high sensitivity and specificity. A prediction model value of more than 0.074 implies that the TI-RADS 3 nodule has undergone a malignant transformation, and fine needle aspiration is recommended in these cases.

Can we better advise our patients with nodular thyroid disease?

BACKGROUND

The 2014 British Thyroid Association guidelines acknowledged the value of risk-stratifying thyroid nodules by utilising an ultrasound reporting system ('U' classification). This study assessed whether using pre-existing parameters in combination can better stratify patients' malignancy and completion thyroidectomy risks.

METHOD

A multicentre, retrospective, observational review identified 936 NHS Greater Glasgow and Clyde patients from pathology records who underwent hemithyroidectomy between 1 January 2014 and 31 December 2019.

RESULTS

A total of 308 patients had thyroid malignancy, 180 (58.4 per cent) progressed to completion thyroidectomy. A nodule classified as 'U3' (indeterminate) was associated with a 35.4 per cent chance of malignancy and a 21.6 per cent risk of requiring completion surgery. Amalgamation of 'U' score with Thy score enhanced risk prediction. The malignancy rate in U3, Thy-3f nodules was 38 per cent, and 21 per cent required completion surgery. The malignancy and completion thyroidectomy rates were comparatively lower for U3, Thy-3a nodules (22 per cent and 14.3 per cent, respectively).

CONCLUSION

Combining ultrasound 'U' score and Thy score improves pre-operative thyroid nodule risk stratification, leading to better informed patients regarding the risks of malignancy and completion surgery. A move towards an integrated assessment approach should be considered.

Unnecessary thyroid surgery rate for suspicious nodule in the absence of molecular testing

Background

Molecular tests for suspicious thyroid nodules decrease rates of unnecessary surgeries but are not widely used due to reimbursement issues. The aim of this study was to assess the rate of unnecessary surgery performed in real-life setting for Bethesda III, IV and V nodules in the absence of molecular testing.

Method

This is a single-center retrospective study of consecutive patients undergoing fine needle aspiration cytology (FNAC) with rapid on-site evaluation between January 2017 and December 2021. Unnecessary surgery was defined as surgery performed because of Bethesda III, IV, or V results in the absence of local compressive symptoms with final benign pathology and as second surgery for completion thyroidectomy.

Results

In the 862 patients (640 females, mean age: 54.2 years), 1010 nodules (median size: 24.4 mm) underwent 1189 FNAC. Nodules were EU-TIRADS 2, 3, 4, and 5 in 3%, 34%, 42%, and 22% of cases, respectively. FNAC was Bethesda I, II, III, IV, V, and VI in 8%, 48%, 17%, 17%, 3%, and 6%, respectively. Surgery was performed in 36% of Bethesda III nodules (benign on pathology: 81%), in 74% of Bethesda IV nodules (benign on pathology: 76%) and in 97% of Bethesda V nodules (benign on pathology: 21%). Surgery was considered unnecessary in 56%, 68%, and 21% of patients with Bethesda III, IV, and V nodules, respectively.

Conclusion

In this real data cohort surgery was unnecessary in more than half of patients with Bethesda III and IV nodules and in 21% of patients with Bethesda V nodules.

2023 European Thyroid Association Clinical Practice Guidelines for thyroid nodule management

With the widespread use of sensitive imaging techniques, which include neck visualization, a conspicuous number of thyroid nodules emerge and demand attention. Most lesions are benign, asymptomatic, and do not warrant treatment. In the case of cancer diagnosis, most are small, intrathyroidal and indolent neoplasms that can safely be managed conservatively. There is a pronounced need for more cost-effective, risk-adapted approaches to the management of this highly prevalent condition, taking the wishes of the patient into consideration. Thus, the present guidelines aim at providing a clinical practice guide for the initial workup and the subsequent management of adult individuals harboring thyroid nodules. Importantly, these guidelines are not intended to cover the management of thyroid malignancy. The manuscript and the specific recommendations were developed by reconciling the best available research evidence with the knowledge and clinical experience of the panelists and updating aspects of a number of previous European Thyroid Association guidelines.

Comparative Study of C-TIRADS, ACR-TIRADS, and EU-TIRADS for Diagnosis and Management of Thyroid Nodules

RATIONALE AND OBJECTIVES

Chinese Thyroid Imaging Reporting and Data Systems (C-TIRADS) was developed to provide a more simplified tool for stratifying thyroid nodules. Here we aimed to validate the efficacy of C-TIRADS in distinguishing benign from malignant and in guiding fine-needle aspiration biopsies in comparison with the American College of Radiology TIRADS (ACR-TIRADS) and European TIRADS (EU-TIRADS).

MATERIALS AND METHODS

This study retrospectively included 3438 thyroid nodules (≥10 mm) in 3013 patients (mean age, 47.1 years ± 12.9) diagnosed between January 2013 and November 2019. Ultrasound features of the nodules were evaluated and categorized according to the lexicons of the three TIRADS. We compared these TIRADS by using the area under the receiver operating characteristic curve (AUROC), the area under the precision-recall curve (AUPRC), sensitivity, specificity, net reclassification improvement (NRI), and unnecessary fine-needle aspiration biopsy (FNAB) rate.

RESULTS

Of the 3438 thyroid nodules, 707 (20.6%) were malignant. C-TIRADS showed higher discrimination performance (AUROC, 0.857; AUPRC, 0.605) than ACR-TIRADS (AUROC, 0.844; AUPRC, 0.567) and EU-TIRADS (AUROC, 0.802; AUPRC, 0.455). The sensitivity of C-TIRADS (85.3%) was lower than that of ACR-TIRADS (89.1%) but higher than that of EU-TIRADS (78.4%). The specificity of C-TIRADS (76.9%) was similar to that of EU-TIRADS (78.9%) and higher than that of ACR-TIRADS (69.5%). The unnecessary FNAB rate was lowest with C-TIRADS (21.2%), followed by ACR-TIRADS (41.7%) and EU-TIRADS (58.3%). C-TIRADS obtained significant NRI for recommending FNAB over ACR-TIRADS (19.0%, P < 0.001) and EU-TIRADS (25.5%, P < 0.001).

CONCLUSION

C-TIRADS may be a clinically applicable tool to manage thyroid nodules, which warrants thorough tests in other geographic settings.

Preoperative Evaluation of Thyroid Cancer: A Review of Current Best Practices

OBJECTIVE

The incidence of thyroid cancer has significantly increased in recent decades. Although most thyroid cancers are small and carry an excellent prognosis, a subset of patients present with advanced thyroid cancer, which is associated with increased rates of morbidity and mortality. The management of thyroid cancer requires a thoughtful individualized approach to optimize oncologic outcomes and minimize morbidity associated with treatment. Because endocrinologists usually play a key role in the initial diagnosis and evaluation of thyroid cancers, a thorough understanding of the critical components of the preoperative evaluation facilitates the development of a timely and comprehensive management plan. The following review outlines considerations in the preoperative evaluation of patients with thyroid cancer.

METHODS

A clinical review based on current literature was generated by a multidisciplinary author panel.

RESULTS

A review of considerations in the preoperative evaluation of thyroid cancer is provided. The topic areas include initial clinical evaluation, imaging modalities, cytologic evaluation, and the evolving role of mutational testing. Special considerations in the management of advanced thyroid cancer are discussed.

CONCLUSION

Thorough and thoughtful preoperative evaluation is critical for formulating an appropriate treatment strategy in the management of thyroid cancer.

History of Thyroid Ultrasound

From low-resolution images in the 1960s to current high-resolution technology, ultrasound has proven to be the initial imaging modality of choice for thyroid application. Point-of-care ultrasound has brought the technology to the thyroid specialist. Combined with physical examination, it provides real-time information regarding goiter, thyroid nodules, and thyroid cancer. Ultrasound-guided fine-needle aspiration biopsy has become the accepted norm, with biopsies rarely performed using palpation alone. Advantages of ultrasound-guided biopsy include precise placement of the needle within the nodule, selective sampling of areas with suspicious features, and accurate direction of the biopsy needle to actively growing viable cells in the periphery of the nodule. Education of endocrinologists in thyroid ultrasound began in the late 1990s and by 2016 more than 6000 clinicians had completed an ultrasound course. Concurrent with this rapid expansion of use of thyroid ultrasound was a rise in the diagnosis of small papillary carcinomas, which might have otherwise remained indolent and undetected. The 2009 American Thyroid Association Guidelines for the Management of Thyroid Nodules and Thyroid Cancer recommended biopsy for all solid hypoechoic nodules measuring larger than 1 cm. Attempting to decrease the frequency of biopsies of low-risk nodules, subsequent guidelines have focused on identifying and selectively biopsying those thyroid nodules at higher risk of clinically significant carcinoma based on ultrasound appearance. A major role for thyroid ultrasound has been in both preoperative staging and mapping to help determine the extent of surgery, as well as postoperative monitoring for locoregional soft tissue or lymph node metastases. With the recognition that the increase in papillary carcinoma was predominantly a result of early diagnosis of small often indolent cancers, active surveillance has become a promising management strategy for papillary thyroid microcarcinomas. Thyroid ultrasound is essential to active surveillance of thyroid cancer. Easy access to high-quality ultrasound studies is a requirement for a successful active surveillance program. Thyroid ultrasound has been used to facilitate interventional procedures, including treatment of thyroid nodules, treatment of recurrent thyroid cancer, and therapy of papillary thyroid microcarcinoma.

The sensitivity of TIRADS scoring on ultrasonography in the management of thyroid nodules

Objective

To determine the sensitivity of ACR-TIRADS scoring by comparing its results with those obtained on biopsy of respective specimens.

Method

This prospective study including N=205 patients with thyroid nodules was conducted in ENT Department of MTI Hayatabad Medical complex, Peshawar during the period from May 1, 2019 to April 30, 2022. Preoperative ultrasonography with assigning of TIRADS scores was performed in all patients. Appropriate thyroidectomies were performed in these patients and specimen biopsied. Pre-op TIRADS scores were compared with biopsy results. To determine the sensitivity of TIRADS, TR1 and TR2 were considered 'benign' and TR3, TR4, TR5 were considered 'malignant' for comparison with biopsy results.

Results

The mean age of patients was 37.68 years with standard deviation of ±11.52. The M: F ratio was 1:3.5. Nineteen patients (9.27%) had solitary thyroid nodules & 186 (90.73%) had multinodular goiters. TIRADS scoring was benign for 171 (83.41%) and malignant for 34 (16.58%) nodules. The biopsy results revealed 180 (87.80%) nodules to benign and the rest as malignant. The sensitivity, specificity and diagnostic accuracy were calculated at 80%, 92.77% and 91.21% respectively. Chi square test and p-value determination showed that there was a strong positive concordance between TIRADS scores & biopsy results which is highly significant (p=.001).

Conclusion

The Ultrasonographic ACR-TIRADS scoring and risk stratification system is highly sensitive for detecting malignancy in thyroid nodules. It is, therefore, a reliable technique in the initial assessment of thyroid nodules and decisions can safely be based on its results. In cases of doubt, clinical judgment should be exercised before making final decision.

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.

A prospective comparison of ACR-TIRADS and EU-TIRADS in thyroid nodule assessment for FNA-US

OBJECTIVE

Prospective data on the accuracy of ultrasound (US) classification systems in thyroid nodules are still scarce. The aim of this study is to compare the accuracy of the American College of Radiology Thyroid Imaging Reporting and Data System (ACR-TIRADS) and European (EU)-TIRADS classification systems.

DESIGN AND PATIENTS

Consecutive patients with one or more thyroid nodule(s) who underwent fine-needle aspiration (FNA) under ultrasonographic guidance (FNA-US) were prospectively evaluated.

MEASUREMENTS

Clinical evaluation and US data were collected. The reference standard used for this study was FNA-US cytology and histopathological diagnosis.

RESULTS

A total of 186 thyroid nodules in 166 patients were evaluated, resulting in 168 nodules from 149 patients with conclusive benign or malignant results. Sensitivity, specificity, negative predictive value (NPV) and false negative (FN) were 100.0%, 28.7%, 100.0% and 0.0%, respectively, for ACR-TIRADS; and 90.0%, 19.1%, 96.8% and 9.1% (n = 1), respectively, for EU-TIRADS. The number of unnecessary FNA-US indicated by ACR-TIRADS was lower than EU-TIRADS (71.3% vs. 80.9%, p = .017), and the number of possibly avoided FNA-US was higher (26.7% vs. 17.8%). Using the same threshold of ACR-TIRADS to indicate FNA-US in EU-TIRADS 3 nodules (2.5 cm), there was an improvement in specificity (30.6%) and avoided FNA-US (28.6%). The best performance of both systems was demonstrated when FNA-US would be indicated only in highly suspicious nodules and/or in the presence of lymphadenopathy, with 85.7% and 89.3% of possibly avoided FNA-US for ACR-TIRADS and EU-TIRADS, respectively, without increasing FN.

CONCLUSION

Both systems presented high sensitivity, but low specificity in selecting nodules for FNA-US. The use of nodular size for FNA-US selection is questioned.

SFE-AFCE-SFMN 2022 Consensus on the management of thyroid nodules: Initial work-up for thyroid nodules

The SFE-AFCE-SFMN 2022 consensus deals with the management of thyroid nodules, a condition that is a frequent reason for consultation in endocrinology. In more than 90% of cases, patients are euthyroid, with benign non-progressive nodules that do not warrant specific treatment. The clinician's objective is to detect malignant thyroid nodules at risk of recurrence and death, toxic nodules responsible for hyperthyroidism or compressive nodules warranting treatment. The diagnosis and treatment of thyroid nodules requires close collaboration between endocrinologists, nuclear medicine physicians and surgeons, but also involves other specialists. Therefore, this consensus statement was established jointly by 3 societies: the French Society of Endocrinology (SFE), French Association of Endocrine Surgery (AFCE) and French Society of Nuclear Medicine (SFMN); the various working groups included experts from other specialties (pathologists, radiologists, pediatricians, biologists, etc.). This section deals with the initial work-up for thyroid nodules in adult patients, including clinical and biological evaluation, standardized ultrasound characterization and EU-TIRADS-based nodule selection for fine-needle aspiration biopsy. Indications for thyroid core-biopsies or open surgical biopsies and for cross-sectional imaging of the neck and upper chest are also mentioned.

Combined Shear Wave Elastography and EU TIRADS in Differentiating Malignant and Benign Thyroid Nodules

Although multimodal ultrasound approaches have been suggested to potentially improve the diagnosis of thyroid cancer; the diagnostic utility of the combination of SWE and malignancy-risk stratification systems remains vague due to the lack of standardized criteria. The purpose of the study was to assess the diagnostic value of the combination of grey scale ultrasound assessment using EU TIRADS and shear wave elastography. 121 patients (126 nodules−81 benign; 45 malignant) underwent grey scale ultrasound and SWE imaging of nodules between 0.5 cm and 5 cm prior to biopsy and/or surgery. Nodules were analyzed based on size stratifications: <1 cm (n = 43); 1−2 cm (n = 52) and >2 cm (n = 31) and equivocal cytology status (n = 52), and diagnostic performance assessments were conducted. The combination of EU TIRADS with SWE using the SD parameter; maintained a high sensitivity and significantly improved the specificity of sole EU TIRADS for nodules 1−2 cm (SEN: 72.2% vs. 88.9%, p > 0.05; SPEC: 76.5% vs. 55.9%, p < 0.01) and >2 cm (SEN: 71.4% vs. 85.7%, p > 0.05; SPEC: 95.8% vs. 62.5%, p < 0.01). For cytologically-equivocal nodules; the combination with the SWE minimum parameter resulted in a significant reduction in sensitivity with increased specificity (SEN: 60% vs. 80%; SPEC: 83.4% vs. 37.8%; all p < 0.05). SWE in combination with EU TIRADS is diagnostically efficient in discriminating nodules > 1 cm but is not ideal for discriminating cytologically-equivocal nodules.

Diagnostic Value of AngioPLUS Microvascular Imaging in Thyroid Nodule Diagnosis Using Quantitative and Qualitative Vascularity Grading

This study investigated the diagnostic value of the Angio Planewave Ultrasensitive (AngioPLUS) Doppler ultrasound in improving the efficacy of grey scale ultrasound in thyroid nodule diagnosis. The EU TIRADS was used for the grey scale ultrasound assessment of 94 thyroid nodules. conventional Doppler and AngioPLUS Doppler ultrasound images were evaluated using qualitative vascularity grading, where predominant central vascularity indicated malignancy-suspicion, and quantitative regional vascularity assessment, where predominant peripheral vascularity using a ratio vascularity index (RVI) of > 1 indicated benign disease. Diagnostic performance outcomes of sole and combination approaches were calculated based on final pathologic results. Using sole EU TIRADS and AngioPLUS + power Doppler imaging (APDI) based on qualitative vascularity and RVI, the results were a sensitivity of 83.3% vs. 83.3 vs. 66.7% and a specificity of 50% vs. 81.3% vs. 73.4, respectively. EU TIRADS combined with APDI significantly improved the specificity using both qualitative vascularity and RVI assessment approaches (84.4% and 81%, respectively, p < 0.05); and slightly reduced the sensitivity (76.7% and 58.1%). For cytologically-equivocal thyroid nodules, the combination approach using qualitative vascularity assessment outperformed the EU TIRADS (sensitivity: both were 88.9%; specificity: 77.4% vs. 38.7%, p < 0.05; and AUROC: 0.83 vs. 0.62, p < 0.05). APDI combined with EU TIRADS is diagnostically efficient in stratifying thyroid nodules, particularly cytologically-equivocal nodules.

Repeat thyroid FNAC: Inter-observer agreement among high- and low-volume centers in Naples metropolitan area and correlation with the EU-TIRADS

Our institution (University Hospital "L. Vanvitelli" - Naples, Italy) is a high-volume (HV) center in Naples metropolitan area and many patients are referred there to repeat thyroid fine-needle aspiration cytology (FNAC) after initial FNAC performed in low-volume institutions (LV). The aims of the study were to 1) examine the inter-observer agreement between HV and LV institutions according to the Italian thyroid cytology system, and 2) explore how the discordant FNAC reports were distributed in the European Thyroid Imaging and Reporting Data System (EU-TIRADS) categories. All consecutive cases of repeat FNAC performed at University Hospital "L. Vanvitelli" from January 2016 to December 2021 were retrospectively reviewed. Fleiss' kappa (κ) was used to assess the inter-observer agreement, and categorical variables were compared by chi-square testing. P < 0.05 was considered statistically significant. A total of 124 nodules from 124 adults (mean age 49 years; mean maximum diameter 19 mm) were evaluated. Initial FNAC reports at LV were: 4 (3.2%) TIR1c, 64 (51.6%) TIR2, 48 (38.7%) TIR3A, 8 (6.5%) TIR3B, 0 TIR4, 0 TIR5. The overall FNAC reports were significantly different between the LV and HV institutions. At repeated FNAC, cytological diagnosis was unchanged in 64 (51.6%) cases including TIR2 and TIR3A results. A downgraded FNAC diagnosis (i.e., TIR2 vs TIR3A, TIR2 vs TIR3B) was observed in 36 (29%) nodules. An upgraded FNAC diagnosis (i.e., TIR3B vs TIR2, TIR3B vs TIR3A, TIR4 vs TIR3A, TIR5 vs TIR2, TIR5 vs TIR3B) was recorded in 24 (19.4%) nodules. The weighted inter-observer agreement between LV and HV institutions was poor (κ=0.133). Changed FNAC results were significantly (p=0.0023) more frequent in nodules at intermediate/high-risk (i.e., EU-TIRADS 4/5) than in those at no/low risk (EU-TIRADS 2/3) [i.e., 32/48 (66.7%) and 28/76 (36.8%), respectively]. Downgraded FNAC results were significantly more frequent in EU-TIRADS 2/3 (p=0.001) while upgraded FNAC were present only in EU-TIRADS 4/5 (24/24, 100.0%). The inter-observer agreement among LV and HV thyroid services was poor. The EU-TIRADS 4 and 5 categories included all the malignant nodules with FNAC results reclassified as higher risk (i.e., TIR3B-TIR4-TIR5) by the high-volume cytology service.

Diagnostic performance of C-TIRADS in malignancy risk stratification of thyroid nodules: A systematic review and meta-analysis

BACKGROUND

Chinese thyroid imaging reports and data systems (C-TIRADS) is a novel malignancy risk stratification used for thyroid nodule diagnosis and guiding thyroid fine needle aspiration (FNA). In this review, we aim to assess the performance of C-TIRADS in malignancy risk stratification of thyroid nodules.

METHODS

PubMed, Medline, Web of Science, Embase, CNKI, and Wanfang databases were searched until 1 April 2022. Original articles reporting data about C-TIRADS and setting FNA or histology as reference standards were included. C-TIRADS 4A, 4B, and 4C were set as thresholds, respectively, to obtain pooled sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-), diagnostic odds ratio (DOR), and the area under the curve (AUC). Integrated nested Laplace approximation was used for Bayesian bivariate meta-analysis of diagnostic tests.

RESULTS

Sixteen studies were included, evaluating 11,506 thyroid nodules. The rate of malignancy in each risk classification is comparable with that in C-TIRADS. C-TIRADS 4B appeared to have better diagnostic performance than C-TIRADS 4A and 4C. The pooled sensitivity, specificity, LR+, LR-, and DOR of C-TI-RADS 4B were 0.94 (95% CI: 0.89-0.97), 0.70 (95% CI: 0.60-0.79), 3.20 (95% CI: 2.28-4.39), 0.09 (95% CI: 0.05-0.15), and 33.71 (95% CI: 25.51-42.40), respectively. The area under the summary ROC curve was 0.94 (95% CI: 0.90-0.96).

CONCLUSION

C-TIRADS performed well in malignancy risk stratification of thyroid nodules. C-TIRADS 4B showed strong evidence of detecting malignancy.

Evaluation of the efficacy of EU-TIRADS and ACR-TIRADS in risk stratification of pediatric patients with thyroid nodules

BACKGROUND

Pediatric thyroid nodules have a lower prevalence but a higher rate of malignancy (ROM) than those in adults. Ultrasound features suspected of malignancy lead to fine needle aspiration biopsy (FNAB) and subsequent cytological determination, upon which management is decided. Based on the characteristics of ultrasound, to standardize clinician decisions and avoid unnecessary FNAB, the European Thyroid Association and the American Radiology College have established guidelines for Thyroid Imaging, Reporting and Data System (EU-TIRADS and ACR-TIRADS) for ROM stratification of thyroid nodules. The aim of this study is to evaluate the diagnostic performance of ACR-TIRADS and EU-TIRADS in pediatric age.

MATERIALS AND METHODS

Subjects younger than 18 years of age with thyroid nodules greater than 0.5 cm observed in the 2000-2020 period were included.

RESULTS

Data from 200 subjects were collected. The overall ROM was 13%, rising to 26% if nodules with a diameter >1 cm were considered. Patients with a malignant nodule were more likely to have a higher EU-TIRADS score (p=0.03). Missed cancer diagnoses were 26.9%. Using the EU-TIRADS system, 40% of FNABs could have been avoided, while this scoring system would have resulted in FNAB being performed in 12% of cases where the assessment of ultrasound features would not recommend FNAB. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 73.1%, 57.1%, 73.1%, and 50%, respectively. Even considering the ACR-TIRADS, a higher score correlated with a higher ROM (p<0.001). This system missed 6 diagnoses of cancer (23.1%). Using the ACR-TIRADS system, 45.3% of FNABs could have been avoided, while FNAB should have been performed in 12% of cases where it was not recommended by ultrasound characteristics. Sensitivity, specificity, PPV and NPV were 76.9%, 50%, 76.9%, and 42.9%, respectively.

CONCLUSION

The present study confirms the correspondence of the EU-TIRADS and ACR-TIRADS categories with respect to malignancy but indicates not entirely satisfactory performance compared to FNAB alone. However, the use of the two TIRADS systems should be encouraged in multicentre studies to increase their performance and establish paediatric-specific points in the scoring criteria.

Exploring the Performance of Ultrasound Risk Stratification Systems in Thyroid Nodules of Pediatric Patients

Neck ultrasound (nUS) is the cornerstone of clinical management of thyroid nodules in pediatric patients, as well as adults. The current study was carried out to explore and compare the diagnostic performance of the main US-based risk stratification systems (RSSs) (i.e., the American College of Radiology (ACR), European (EU), Korean (K) TI-RADSs and ATA US RSS criteria) for detecting malignant thyroid lesions in pediatric patients. We conducted a retrospective analysis of consecutive children and adolescents who received a diagnosis of thyroid nodule. We included subjects with age <19 years having thyroid nodules with benign cytology/histology or final histological diagnosis. We excluded subjects with (a) a previous malignancy, (b) a history of radiation exposure, (c) cancer genetic susceptibility syndromes, (d) lymph nodes suspicious for metastases of thyroid cancer at nUS, (e) a family history of thyroid cancer, or (f) cytologically indeterminate nodules without histology and nodules with inadequate cytology. We included 41 nodules in 36 patients with median age 15 years (11-17 years). Of the 41 thyroid nodules, 29 (70.7%) were benign and 12 (29.3%) were malignant. For both ACR TI-RADS and EU-TIRADS, we found a sensitivity of 41.7%. Instead, for both K-TIRADS and ATA US RSS, we found a sensitivity of 50%. The missed malignancy rate for ACR-TIRADS and EU-TIRADS was 58.3%, while that for K-TIRADS and ATA US RSS was 50%. The unnecessary FNA prevalence for ACR TI-RADS and EU-TIRADS was 58.3%, while that for K-TIRADS and ATA US RSS was 76%. Our findings suggest that the four US-based RSSs (i.e., ACR-TIRADS, EU-TIRADS, K-TIRADS, and ATA US RSS) have suboptimal performance in managing pediatric patients with thyroid nodules, with one-half of cancers without indication for FNA according to their recommendations.

Artificial Intelligence in Thyroid Field-A Comprehensive Review

Simple Summary

The incidence of thyroid pathologies has been increasing worldwide. Historically, the detection of thyroid neoplasms relies on medical imaging analysis, depending mainly on the experience of clinicians. The advent of artificial intelligence (AI) techniques led to a remarkable progress in image-recognition tasks. AI represents a powerful tool that may facilitate understanding of thyroid pathologies, but actually, the diagnostic accuracy is uncertain. This article aims to provide an overview of the basic aspects, limitations and open issues of the AI methods applied to thyroid images. Medical experts should be familiar with the workflow of AI techniques in order to avoid misleading outcomes.

Abstract

Artificial intelligence (AI) uses mathematical algorithms to perform tasks that require human cognitive abilities. AI-based methodologies, e.g., machine learning and deep learning, as well as the recently developed research field of radiomics have noticeable potential to transform medical diagnostics. AI-based techniques applied to medical imaging allow to detect biological abnormalities, to diagnostic neoplasms or to predict the response to treatment. Nonetheless, the diagnostic accuracy of these methods is still a matter of debate. In this article, we first illustrate the key concepts and workflow characteristics of machine learning, deep learning and radiomics. We outline considerations regarding data input requirements, differences among these methodologies and their limitations. Subsequently, a concise overview is presented regarding the application of AI methods to the evaluation of thyroid images. We developed a critical discussion concerning limits and open challenges that should be addressed before the translation of AI techniques to the broad clinical use. Clarification of the pitfalls of AI-based techniques results crucial in order to ensure the optimal application for each patient.

Facing Thyroid Nodules in Paediatric Patients Previously Treated with Radiotherapy for Non-Thyroidal Cancers: Are Adult Ultrasound Risk Stratification Systems Reliable?

Simple Summary

The risk of thyroid nodules harbouring cancer has been evaluated, in adults, using specific ultrasound criteria. However, it is unclear whether such evaluation can be translated in paediatric patients. In this study, we tested the effectiveness of three known risk evaluation systems in children with thyroid nodules and with a history of radiation exposure. We found that these systems are reliable in confirming or ruling out cancer in most cases, except when evaluating very small nodules (<1 cm). For these reasons, these risk criteria should be adopted to account for the reduced size of malignant lesions when evaluating paediatric subjects.

Abstract

Thyroid nodule ultrasound-based risk stratification systems (US-RSSs) have been successfully used in adults to predict the likelihood of malignancies. However, their applicability to the paediatric population is unclear, especially in children with a history of radiation exposure, who are at a higher cancer risk. We tested the efficacy of three US-RSSs in this setting by retrospectively applying three classification systems (ACR-TIRADS, ATA and EU-TIRADS) to all paediatric patients referred for thyroid nodules and with a radiation exposure history. We compared the results with a reference standard (pathology or 36-month follow-up); sensitivity, specificity, positive and negative predictive values (PPV and NPV) and accuracy were calculated. A total of 52 patients were included; fourteen of them (27%) had papillary thyroid cancer (PTC) at the final histology. No significant differences across the US-RSSs were detected; specificity (range 95–97%) and NPV (range 88–93%) were particularly elevated. However, ACR-TIRADS, ATA and EU-TIRADS did not indicate the need for a biopsy in six (42.8%), seven (50%) and eight (57%) cases of PTC; in five cases, this lack of indication was due to a small (<1 cm) nodule size. In conclusion, US-RSSs show a high NPV and specificity in paediatric patients, whereas the cytology indication could be improved by reconsidering the dimensional criterion.