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

To diagnose primary and secondary squamous cell carcinoma of the thyroid with ultrasound malignancy risk stratification

Objectives

This study aimed to investigate the clinico-ultrasound features of primary squamous cell carcinoma of the thyroid (PSCCT) and secondary SCCT (SSCCT) and evaluate the accuracy of fine needle aspiration (FNA) recommendation for SCCT with American College of Radiology-Thyroid Imaging and Reporting Data System (ACR-TIRADS) and Chinese-TIRADS (C-TIRADS).

Materials and methods

We retrieved 26 SCCT patients (11 PSCCT, 15 SSCCT) from our hospital's pathology database (5,718 patients with thyroid malignancy) over 23 years. Medical records and ultrasound data of the 26 patients with 27 SCCTs were analyzed retrospectively, and each SCCT focus was categorized based on the two TIRADSs.

Results

For 26 patients (21 males, 5 females) with an age range of 42-81 years, rapidly enlarging thyroid/neck nodules (18/26, 69.2%), dysphagia (7/26, 26.9%), hoarseness (6/26, 23.1%), dyspnea (5/26, 19.6%), cough (4/26, 15.4%), neck pain (2/26, 7.7%), B symptoms (2/26, 7.7%), and blood in sputum (1/26, 3.8%) were presented at diagnosis. Five asymptomatic patients (5/26, 19.2%) were detected by ultrasound. Hoarseness was more common in PSCCT (5/11, 45.5%) than in SSCCT (1/15, 6.7%) (P=0.032). For 27 SCCTs with a mean size of 3.7 ± 1.3 cm, the ultrasound features consisted of solid (25/27, 92.6%) or almost completely solid composition (2/27, 7.4%), hypoechoic (17/27, 63%) and very hypoechoic echogenicity (10/27, 37%), irregular/lobulated margin with extra-thyroidal extension (27/27, 100%), taller-than-wide shape (13/27, 48.1%), punctate echogenic foci (6/27, 22.2%), hypervascularity (23/27, 85.2%) and involved neck lymph (13/26, 50.0%). A total of 27 SCCTs were evaluated as high malignancy risk stratification (≥TR4 and 4B) by the two TIRADSs and recommended FNA in 96.3-100% (26/27, 27/27). Pathologically, more than half of PSCCTs (7/12, 58.3%) and a quarter of SSCCTs (4/15, 26.7%) were poorly differentiated, while moderately and well-differentiated grades were observed in 5 PSCCTs and 11 SSCCTs (P=0.007). Thirteen patients (50.0%) underwent surgery with radical operation in 5 cases (5/13, 38.5%).

Conclusion

SCCT is an extremely rare and aggressive malignancy with a male predominance. PSCCT and SSCCT had similar clinical and ultrasound features except for tumor differentiation and the symptom of hoarseness. SCCT showed a high malignancy risk stratification in ACR-TIRADS and C-TIRADS, with a high rate of FNA recommendation.

Comparison the accuracy of thyroid sono-elastography vs. ultrasound-guided fine needle aspiration cytology with thyroid malignancy diagnosis histopathology

Objective. The intend of the present study was to assess the diagnostic performance of strain elastography in investigating the thyroid nodule malignancy taking the surgical biopsy as a gold standard reference test. Methods. The study included 120 patients with 123 thyroid nodules, of which 67 had total thyroidectomy. The American College of Radiology Thyroid Imaging Reporting and Data Systems (ACR-TIRADS) were evaluated for all nodules. All suspicious nodules were referred for a fine needle aspiration cytology (FNAC) if they fulfilled the required size. Strain elastography was performed for each suspicious nodule. Ultrasound-guided FNAC was performed for all suspicious nodules. Total thyroidectomy was performed in those whom the suspicious nodules were proven by FNAC. Results. Strain ratio had a sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of 84%, 81%, 95%, 85%, and 84%, respectively, with a cut point 1.96. Elasticity score had a sensitivity, specificity, PPV, NPV, and diagnostic accuracy of 100%, 80%, 95%, 85% and 87%, respectively, with a cut point 0.96. The elasticity score had a statistically significantly odds ratio for detecting the benignity 3.9 C. I (1.6-9.3). Conclusion. Strain elastography has a high diagnostic performance in detecting the malignant as well as benign nodules, thus it can limit the rate of unneeded FNAC or surgery especially among B3 and B4 groups with indeterminate cytology.

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

Background

The performance in evaluating thyroid nodules on ultrasound varies across different risk stratification systems, leading to inconsistency and uncertainty regarding diagnostic sensitivity, specificity, and accuracy.

Objective

Comparing diagnostic performance of detecting thyroid cancer among distinct ultrasound risk stratification systems proposed in the last five years.

Evidence acquisition

Systematic search was conducted on PubMed, EMBASE, and Web of Science databases to find relevant research up to December 8, 2022, whose study contents contained elucidation of diagnostic performance of any one of the above ultrasound risk stratification systems (European Thyroid Imaging Reporting and Data System[Eu-TIRADS]; American College of Radiology TIRADS [ACR TIRADS]; Chinese version of TIRADS [C-TIRADS]; Computer-aided diagnosis system based on deep learning [S-Detect]). Based on golden diagnostic standard in histopathology and cytology, single meta-analysis was performed to obtain the optimal cut-off value for each system, and then network meta-analysis was conducted on the best risk stratification category in each system.

Evidence synthesis

This network meta-analysis included 88 studies with a total of 59,304 nodules. The most accurate risk category thresholds were TR5 for Eu-TIRADS, TR5 for ACR TIRADS, TR4b and above for C-TIRADS, and possible malignancy for S-Detect. At the best thresholds, sensitivity of these systems ranged from 68% to 82% and specificity ranged from 71% to 81%. It identified the highest sensitivity for C-TIRADS TR4b and the highest specificity for ACR TIRADS TR5. However, sensitivity for ACR TIRADS TR5 was the lowest. The diagnostic odds ratio (DOR) and area under curve (AUC) were ranked first in C-TIRADS.

Conclusion

Among four ultrasound risk stratification options, this systemic review preliminarily proved that C-TIRADS possessed favorable diagnostic performance for thyroid nodules.

Systematic review registration

https://www.crd.york.ac.uk/prospero, CRD42022382818.

The Size of a Thyroid Nodule with ACR TI-RADS Does Not Provide a Better Prediction of the Nature of the Nodule: A Single-Center Retrospective Real-Life Observational Study

We investigated if thyroid nodule size has a predictive value of malignancy on a par with composition, echogenicity, shape, margin, and echogenic foci, and what would be the consequence of observing the rule of the American College of Radiology (ACR) to perform a fine-needle aspiration biopsy (FNAB). We conducted a retrospective real-life observational study on 86 patients who underwent surgery after a standardized diagnostic protocol. We divided the TR3, TR4, and TR5 classes into sub-classes according to the size threshold indicating FNAB (a: up to the threshold for no FNAB; b: over the threshold for FNAB suggested). We computed sensitivity, specificity, and positive (PPV) and negative predictive value (NPV) for the different sub-classes and Youden's index (Y) for the different possible cutoffs. Each sub-class showed the following PPV (0.67, 0.68, 0.70, 0.78, 0.72), NPV (0.56, 0.54, 0.51, 0.52, 0.59), and Y (0.20, 0.20, 0.22, 0.31, 0.30). In this real-life series, we did not find a significant difference in prediction of malignancy between the sub-categories according to the size threshold. All nodules have a pre-evaluation likelihood of being malignant, and the impact and utility of size thresholds may be less clear than suggested by the ACR TIRADS guidelines in patients undergoing standardized thyroid work up.

Analysis and Comparison of the Malignant Thyroid Nodules Not Recommended for Biopsy in ACR TIRADS and AI TIRADS With a Large Sample of Surgical Series

OBJECTIVE

To determine if the artificial intelligence-based Thyroid Imaging, Reporting and Data System (AI TIRADS) would perform better than the American College of Radiology (ACR) TIRADS in monitoring malignant thyroid nodules not recommended for biopsy using follow-up thresholds.

METHODS

A total of 3499 thyroid nodules with surgical histopathology and ultrasound features were retrospectively reviewed and categorized using ACR TIRADS and AI TIRADS. The recommendations for biopsy and follow-up divided nodules into three groups 1) fine needle aspiration (FNA), 2) follow-up ultrasound, and 3) no further evaluation.

RESULTS

Of the total 1608 malignant nodules in this study, 974 malignant nodules would not be biopsied in ACR TIRADS compared with 967 in AI TIRADS. While 60.0% (584/974) of these non-biopsied malignancies could be followed-up by ultrasound in ACR TIRADS and 62.8% (607/967) in AI TIRADS. For the malignancies of no further evaluation, 97.4% (380/390) were sized <10 mm in ACR TIRADS and 93.3% (336/360) in AI TIRADS. Compared with ACR TIRADS, AI TIRADS had lower unnecessary FNA rate and missing cancer rate (41.0% vs 47.8% and 22.8% vs 27.5%, P < .05, respectively) while having higher specificity and AUC as well as lower sensitivity (65.0% vs 57.9%, 0.895 vs 0.881, and 96.1% vs 97.8%, all P < .05).

CONCLUSIONS

Using the follow-up thresholds, more than half of the malignancies not being biopsied were monitored by ultrasound in both ACR TIRADS and AI TIRADS, and AI TIRADS had lower missing cancer rate. More than 90% of malignancies recommended for no further evaluation were <10 mm in diameter.

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.

The feasibility of decreasing the thresholds for biopsy in Kwak and C TIRADSs

Objectives

To estimate the feasibility of decreasing the original thresholds for biopsy in the Kwak Thyroid Imaging Reporting and Data System (Kwak TIRADS) and Chinese Thyroid Imaging Reporting and Data System (C TIRADS).

Methods

This retrospective study included 3,201 thyroid nodules from 2,146 patients with a pathological diagnosis. We lowered the original fine-needle aspiration (FNA) thresholds with the TR4a-TR5 in Kwak and C TIRADSs and calculated the ratio of additional benign-to-malignant nodules being biopsied (RABM). If the RABM is less than 1, the decreased FNA thresholds could be accepted and used to the modified TIRADSs (modified C and Kwak TIRADSs). Then, we estimated and compared the diagnostic performance between the modified TIRADS and the original TIRADS to determine if the decreased thresholds could be an effective strategy.

Results

A total of 1,474 (46.0%) thyroid nodules were diagnosed as malignant after thyroidectomy. The TR4c-TR5 in Kwak TIRADS and TR4b-TR5 in C TIRADS had a rational RABM (RABM < 1). The modified Kwak TIRADS had higher sensitivity, a positive predictive value, a negative predictive value, lower specificity, an unnecessary biopsy rate, and a missed malignancy rate compared with the original Kwak TIRADS (94.1% vs. 42.6%, 59.4% vs. 44.6%, 89.9% vs. 52.8%, 45.0% vs. 54.9%, 40.6% vs. 55.4%, and 10.1% vs. 47.1%, respectively, P < 0.05 for all). Similar trends were seen in the modified C TIRADS versus the original C TIRADS (95.1% vs. 38.7%, 61.7% vs. 47.8%, 92.3% vs. 55.0%, 49.7% vs. 64.0%, 38.3% vs. 52.2%, and 7.7% vs. 44.9%, respectively, P < 0.05 for all).

Conclusions

The biopsy of all nodules with TR4C-TR5 in the Kwak TIRADS and TR4B-TR5 in the C TIRADS might be an effective strategy. This paper contributes to the contradiction concerning whether to perform FNA for the nodules smaller than 10 mm.

A new discriminant strategy combined with four TIRADS screening procedures increases ultrasound diagnostic accuracy-focusing on "wrong diagnostic" thyroid nodules

OBJECTIVE

To utilize the discrepancies of different TIRADS, including ACR-TIRADS, Kwak-TIRADS, C-TIRADS, and EU-TIRADS, to explore methods for improving ultrasound diagnostic accuracy.

METHODS

In total, 795 nodules with cytological or surgical pathology were included. All nodules were screened by the four TIRADS according to their diagnostic concordance (Screening procedures, SP). Discriminant strategy (DS) derived from predictor variables was combined with SP to construct the evaluation method (SP+DS). The diagnostic performance of the SP+DS method alone and its derivational methods and two-TIRADS combined tests was evaluated.

RESULTS

A total of 86.8% (269/310) malignant nodules and 93.6% (365/390) benign cases diagnosed by the four TIRADS simultaneously were pathologically confirmed, while 12.0% (95/795) nodules could not be consistently diagnosed by them. The criteria of DS were that iso- or hyper-echogenicity nodules should be considered benign, while hypo- or marked hypo-echogenicity nodules malignant. For 95 inconsistently diagnosed nodules screened by at least two TIRADS, DS performed best with an accuracy of 79.0%, followed by Kwak-TIRADS (72.6%). In the overall sample, the sensitivity and AUC were highest for the SP+DS method compared to the four TIRADS (91.3%, 0.895). Combining ACR-TIRADS and Kwak-TIRADS via parallel test resulted in significant improvements in the sensitivity and AUC compared to ACR-TIRADS (89.2% vs. 81.4%, 0.889 vs. 0.863). Combining C-TIRADS and DS in serial resulted in the highest AUC (0.887), followed by Kwak-TIRADS (0.884), while EU-TIRADS was the lowest (0.879).

CONCLUSIONS

For undetermined or suspected thyroid nodules, two-TIRADS combined tests can be used to improve diagnostic accuracy. Otherwise, considering the inconsistent diagnosis of two TIRADS may require attention to the echo characteristics to differentiate between benign and malignant nodules.

KEY POINTS

• The discrepancies in the diagnostic performance of different TIRADS arise from their performance on inconsistently diagnosed nodules. • ACR-TIRADS improves sensitivity via combining with Kwak-TIRADS in parallel (from 81.4 to 89.2%), while C-TIRADS increases specificity via combining with EU-TIRADS in serial (from 80.9 to 85.7%). • If the diagnostic findings of two TIRADS are inconsistent, echo characteristics will be helpful for the differentiation of benign and malignant nodules with an accuracy of 79.0%.