Retrospective Application of the 2015 American Thyroid Association Guidelines for Ultrasound Classification, Biopsy Indications, and Follow-up Imaging of Thyroid Nodules: Can Improved Reporting Decrease Testing?

Assessment of diagnostic capacity and decision-making based on the 2015 American Thyroid Association ultrasound classification system

BACKGROUND

This study evaluates the American Thyroid Association (ATA) ultrasound (US) classification system for the initial assessment of thyroid nodules to determine if it indeed facilitates clinical decision-making.

AIM

To perform a systematic review and meta-analysis of the diagnostic value of the ATA US classification system for the initial assessment of thyroid nodules.

METHODS

In accordance with the PRISMA statement for diagnostic test accuracy, we selected articles that evaluated the 2015 ATA US pattern guidelines using a diagnostic gold standard. We analyzed these cases using traditional diagnostic parameters, as well as the threshold approach to clinical decision-making and decision curve analysis.

RESULTS

We reviewed 13 articles with 8445 thyroid nodules, which were classified according to 2015 ATA patterns. Of these, 46.62% were malignant. No cancer was found in any of the ATA benign pattern nodules. The Bayesian analysis post-test probability for cancer in each classification was: (1) Very-low suspicion, 0.85%; (2) Low, 2.6%; (3) Intermediate, 6.7%; and (4) High, 40.9%. The net benefit (NB), expressed as avoided interventions, indicated that the highest capacity to avoid unnecessary fine needle aspiration biopsy (FNAB) in the patterns that we studied was 42, 31, 35, and 43 of every 100 FNABs. The NB calculation for a probability threshold of 11% for each of the ATA suspicion patterns studied is less than that of performing FNAB on all nodules.

CONCLUSION

These three types of analysis have shown that only the ATA high-suspicion diagnostic pattern is clinically useful, in which case, FNAB should be performed. However, the curve decision analysis has demonstrated that using the ATA US risk patterns to decide which patients need FNAB does not provide a greater benefit than performing FNAB on all thyroid nodules. Therefore, it is likely that a better way to approach the assessment of thyroid nodules would be to perform FNAB on all non-cystic nodules, as the present analysis has shown the ATA risk patterns do not provide an adequate clinical decision-making framework.

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

Simple Summary

The aim of this review is to provide the reader with a comprehensive overview of thyroid imaging and reporting data systems used for thyroid nodules, so as to understand how nodules are scored with all existing systems. Both ultrasound based risk stratification systems and indications for fine-needle aspirations are described. Systems are compared by analyzing their strengths and weaknesses. Studies show satisfactory sensitivities and specificities for the diagnosis of malignancy for all systems, and none of them have shown a real significant advantage over the others in terms of raw diagnostic value. Interobserver agreement is also very similar for all systems, fairly adequate to robust. Dimensional cut-offs for fine-needle aspiration are quite similar and all RSSs seem to reduce effectively the number of unnecessary FNAs. Merging all existing systems in a common international one is desirable.

Abstract

Since 2009, thyroid imaging reporting and data systems (TI-RADS) have been playing an increasing role in the field of thyroid nodules (TN) imaging. Their common aims are to provide sonologists of varied medical specialties and clinicians with an ultrasound (US) based malignancy risk stratification score and to guide decision making of fine-needle aspiration (FNA). Schematically, all TI-RADSs scores can be classified as either pattern-based or point-based approaches. The main strengths of these systems are their ability (i) to homogenize US TN descriptions among operators, (ii) to facilitate and shorten communication on the malignancy risk of TN between sonologists and clinicians, (iii) to provide quantitative ranges of malignancy risk assessment with high sensitivity and negative predictive values, and (iv) to reduce the number of unnecessary FNAs. Their weaknesses are (i) the remaining inter-observer discrepancies and (ii) their insufficient sensitivity for the diagnosis of follicular cancers and follicular variant of papillary cancers. Most common pitfalls are degenerating shrinking nodules and confusion between individual and coalescent nodules. The benefits of all TI-RADSs far outweigh their shortcomings, explaining their rising use, but the necessity to improve and merge the different existing systems remains.

Presence of Metabolic Syndrome and Thyroid Nodules in Subjects with Colorectal Polyps

Background

Thyroid nodules (TNs) and metabolic syndrome (MS) have been individually associated with colorectal polyps. However, the potential joint relationship between them in relation to colorectal polyps has not been fully evaluated. This study aimed to validate the association of TNs/MS and colorectal polyps/adenomas and to determine the risk of colonic polyps in patients with TNs/MS.

Material/Methods

A retrospective study was conducted on patients undergoing routine health checks in the First Affiliated Hospital of Wenzhou Medical University from July 2014 to August 2017. Univariate and multivariate logistic regression analyses were performed to identify independent risk factors for colorectal polyps/adenomas after adjusting for confounding factors. Then patients were divided into 4 groups according to whether they had TNs or MS. Relative excess risks of interaction, attributable proportion, and synergy index were used to determine the additive interaction of TNs and MS on colorectal polyps/adenomas.

Results

A total of 4514 eligible patients were included in this study. TNs and MS were confirmed to be independent risk factors for colorectal polyps/adenomas. Compared with the group of TNs(−)/MS(−), the odds ratios of TNs(+)/MS(+) in colorectal polyps (odds ratio [OR]: 3.031, 95% confidence interval [CI]: 2.262–4.062, P<0.05) or adenomas (OR: 2.894, 95% CI: 2.099–3.990, P<0.05) were significantly increased, and there was an interactive additive effect between TNs and MS.

Conclusions

TNs and MS have an associative and superimposing effect on the increased occurrence of colorectal adenomas. Colonoscopy screening should be advocated for patients with both of these diseases.

Comparison of Diagnostic Performance of Five Different Ultrasound TI-RADS Classification Guidelines for Thyroid Nodules

Objectives

We aimed to evaluate and compare the diagnostic performance of five ultrasound thyroid imaging reporting and data system (TI-RADS) classification guidelines for thyroid nodules through a review and meta-analysis.

Methods

We searched for relevant studies before February 2020 in PubMed. Then we pooled the sensitivity, specificity, likelihood ratios, diagnostic odds ratios, and area under the summary receiver operating characteristic curves. And the diagnostic odds ratios were used to compare the performance.

Results

We totally included 19 studies with 4,696 lesions in this research. The pooled sensitivity of American College of Radiology (ACR) guidelines, American Thyroid Association (ATA) guidelines, TI-RADS proposed by Kwak (Kwak TI-RADS), Korean Thyroid Association/Korean Society of Thyroid Radiology (KTA/KSThR) guidelines for malignancy risk and European Thyroid Association (ETA) guidelines is between 0.84 and 0.94. The pooled specificity is 0.68, 0.44, 0.62, 0.47, and 0.61, respectively. And the RDOR is 1.57 (ACR vs ATA), 1.37 (ACR vs ETA), 1.80 (ACR vs Kawk), 1.74 (ARC vs KTA).

Conclusions

The results suggest that five classification guidelines are all effective methods for differential diagnosis of benign and malignant thyroid nodules and ACR guideline is a better choice.

Performance of Five Ultrasound Risk Stratification Systems in Selecting Thyroid Nodules for FNA

CONTEXT

Ultrasound (US) risk stratification systems (RSSs) have been developed to reduce the number of unnecessary fine-needle aspiration procedures (FNA) in patients with thyroid nodules.

OBJECTIVE

We conducted a systematic review and meta-analysis evaluating the ability of the 5 most common US RSSs for the appropriate selection of thyroid nodules for FNA.

DATA SOURCES

This systematic review and meta-analysis was registered on PROSPERO (CRD42019131771). PubMed, CENTRAL, Scopus, and Web of Science were searched until March 2019.

STUDY SELECTION

Original articles reporting data on the performance of AACE/ACE/AME, ACR TI-RADS, ATA, EU-TIRADS, and K-TIRADS were included.

DATA EXTRACTION

The number of nodules classified as true negative, true positive, false negative, and false positive was extracted. Summary operating points were estimated using a random-effects model. Interobserver agreement was also assessed.

DATA SYNTHESIS

Twelve studies evaluating 18 750 thyroid nodules were included. Participants were adult outpatients with thyroid nodules submitted to either FNA or core-needle biopsy or surgery and with available US images. The final diagnosis for malignant nodules was generally based on histology, while cytology was used for benign nodules. Diagnostic odds ratio (DOR) ranged from 2.2 to 4.9. A head-to-head comparison showed a higher relative DOR for ACR-TIRADS versus ATA (P = .002) or K-TIRADS (P = .002), due to a higher relative likelihood ratio for positive results.

CONCLUSIONS

The present meta-analysis found a higher performance of ACR TI-RADS in selecting thyroid nodules for FNA. However, the comparison across the most common US RSSs was limited by the data available. Further studies are needed to confirm this finding.