Thyroid nodules stratification by American Thyroid Association and American College of Radiology lexicons: Thi-qar study

The diagnostic performance of sonography to manage thyroid nodule (TN) may influence excess biopsy in different clinical settings. American College of Radiology (ACR) presented Thyroid Imaging Reporting and Data Systems (TIRADS) lator to American Thyroid Association (ATA) risk stratification guidelines, with variable diagnostic performance. The objective of this study is to evaluate the effectiveness of ACR-TIRADS versus ATA lexicons for thyroid cancer prediction among individuals with TN in Thi-Qar, Iraq. This cross-sectional observational study enrolled 1,007 individuals aged ≥ 14 years with 1,155 TNs attending a tertiary endocrine center. Malignancy risk was classified using both ACR-TIRADS and ATA lexicons with matched categories: TIRAD-1 (Benign<1%), TIRAD-2 (Very Low<3%), (TIRAD-3 (Low 5-10%), (TIRAD-4 (Intermediate 10-20%), and (TIRAD-5 (High 70-90%). Fine needle aspiration (FNAC) and histopathological diagnosis were made according to the Bethesda system and agreement between lexicons was assessed using sensitivity, specificity, Cohen’s Kappa Statistics, and McNemar test. Among participants, 85.2% were women, with mean age 46±14 years. Most individuals were euthyroid (71%), TNs were located in right lobe (51.3%), left lobe (42.5%), and isthmus (6.1%). FNAC was indicated for 54.6% of TNs by ATA and 44.6% by ACR-TIRADS criteria. High-risk cytology (Bethesda IV-V) was 7.1% and ATA system demonstrated higher sensitivity (74.3%) and accuracy (58.6%) than ACR-TIRADS (sensitivity 60%, accuracy 53%), though both gave modest diagnostic performance and low positive predictive values (<12%). Agreement between systems was weak (Cohen’s κ=0.265±0.032, p < 0.001), with concordance in 50.1% of cases. Both risk stratification systems had comparable but modest diagnostic performance. ATA identified more FNAC-eligible TNs with slightly higher sensitivity, specificity, prediction, and overall accuracy. However, the weak agreement between raters highlights variability in nodule categorization and management, supporting the need to integrate sonographic findings with clinical and biochemical factors to optimize TNs evaluation and minimize unnecessary biopsies.

1. Gharib H, Papini E, Garber JR, et al; AACE/ACE/AME Task Force on Thyroid Nodules. American Association of Clinical Endocrinologists, American College of Endocrinology, and Associazione Medici Endocrinologi medical guidelines for clinical practice for the diagnosis and management of thyroid nodules--2016 update. Endocr Pract 2016;22:622-39. DOI: https://doi.org/10.4158/EP161208.GL

2. Grani G, Lamartina L, Cantisani V, et al Interobserver agreement of various thyroid imaging reporting and data systems. Endocr Connect 2018;7:1-7. DOI: https://doi.org/10.1530/EC-17-0336

3. Acar T, Ozbek SS, Acar S. Incidentally discovered thyroid nodules: frequency in an adult population during Doppler ultrasonographic evaluation of cervical vessels. Endocrine 2014;45:73-8. DOI: https://doi.org/10.1007/s12020-013-9949-3

4. Guth S, Theune U, Aberle J, et al. Very high prevalence of thyroid nodules detected by high frequency (13 MHz) ultrasound examination. Eur J Clin Invest 2009;39:699-706. DOI: https://doi.org/10.1111/j.1365-2362.2009.02162.x

5. American Thyroid Association (ATA) guidelines taskforce on thyroid nodules and differentiated thyroid cancer, Cooper DS, Doherty GM, Haugen BR, et al. Revised American Thyroid Association management guidelines for patients with thyroid nodules and differentiated thyroid cancer. Thyroid 2009;19:1167-214. DOI: https://doi.org/10.1089/thy.2009.0110

6. Cibas ES, Ali SZ. The 2017 Bethesda System for reporting thyroid cytopathology. Thyroid 2017;27:1341-6. DOI: https://doi.org/10.1089/thy.2017.0500

7. Haugen BR, Alexander EK, Bible KC, et al, American Thyroid Association management guidelines for adult patients with thyroid nodules and differentiated thyroid cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer. Thyroid 2016;26:1-133. DOI: https://doi.org/10.1089/thy.2015.0020

8. Kwak JY, Han KH, Yoon JH, et al, Thyroid imaging reporting and data system for US features of nodules: a step in establishing better stratification of cancer risk. Radiology 2011;260:892-9. DOI: https://doi.org/10.1148/radiol.11110206

9. Tessler FN, Middleton WD, Grant EG, et al, ACR Thyroid Imaging, Reporting and Data System (TI-RADS): White Paper of the ACR TI-RADS Committee. J Am Coll Radiol 2017;14:587-95. DOI: https://doi.org/10.1016/j.jacr.2017.01.046

10. Smith-Bindman R, Lebda P, Feldstein VA, et al. Risk of thyroid cancer based on thyroid ultrasound imaging characteristics: results of a population-based study. JAMA Intern Med 2013;173:1788-96. DOI: https://doi.org/10.1001/jamainternmed.2013.9245

11. Pandya A, Caoili EM, Jawad-Makki F, et al. Retrospective cohort study of 1947 thyroid nodules: a comparison of the 2017 American College of Radiology TI-RADS and the 2015 American Thyroid Association Classifications. AJR Am J Roentgenol 2020;214:900-6. DOI: https://doi.org/10.2214/AJR.19.21904

12. Lim-Dunham JE, Toslak IE, Reiter MP, Martin B. Assessment of the American College of Radiology Thyroid Imaging Reporting and Data System for thyroid nodule malignancy risk stratification in a pediatric population. AJR Am J Roentgenol 2019;212:188-94. DOI: https://doi.org/10.2214/AJR.18.20099

13. Ahn HS, Kim HJ, Welch HG. Korea's thyroid-cancer "epidemic"--screening and overdiagnosis. N Engl J Med 2014;371:1765-7. DOI: https://doi.org/10.1056/NEJMp1409841

14. Charan J, Biswas T. How to calculate sample size for different study designs in medical research? Indian J Psychol Med 2013;35:121-6. DOI: https://doi.org/10.4103/0253-7176.116232

15. Hussein IH, Altemimi MT, Alidrisi HA, et al. The Performance of the American Thyroid Association (ATA) and American College of Radiology (ACR-TIRAD) thyroid nodule risk-stratification systems in determining high-risk nodules, and the correlation of site, size, and autoimmunity with high-risk features. Indian J Endocrinol Metab 2024;28:622-8. DOI: https://doi.org/10.4103/ijem.ijem_154_23

16. Mansour AA, Abdullah Almomin AMS, et al. SUN-418 patterns of thyroid disease in Basrah, Iraq. Retrospective study. J Endocr Soc 2020;4:SUN-418. DOI: https://doi.org/10.1210/jendso/bvaa046.772

17. Kargar S, Tabatabaei SM, Okati-Aliabad H, Izadi Rad H. Prevalence of thyroid dysfunction disorders among adult populations in the Middle–East: a systematic review and meta-analysis. Open Public Health J 2024;17:e187494452411270. DOI: https://doi.org/10.2174/0118749445317174240827052511

18. Ahmadi S, Oyekunle T, Jiang X', et al. A direct comparison of the ATA and TI-RADS ultrasound scoring systems. Endocr Pract 2019;25:413-22. DOI: https://doi.org/10.4158/EP-2018-0369

19. Grani G, Lamartina L, Ascoli V, et al. Reducing the number of unnecessary thyroid biopsies while improving diagnostic accuracy: toward the "right" TIRADS. J Clin Endocrinol Metab 2019;104:95-102. DOI: https://doi.org/10.1210/jc.2018-01674

20. Merhav G, Zolotov S, Mahagneh A, et al. Validation of TIRADS ACR risk assessment of thyroid nodules in comparison to the ATA Guidelines. J Clin Imaging Sci 2021;11:37. DOI: https://doi.org/10.25259/JCIS_99_2021

21. Koseoglu Atilla FD, Ozgen Saydam B, Erarslan NA, et al. Does the ACR TI-RADS scoring allow us to safely avoid unnecessary thyroid biopsy? single center analysis in a large cohort. Endocrine 2018;61:398-402. DOI: https://doi.org/10.1007/s12020-018-1620-6

22. Gao L, Xi X, Jiang Y, et al. Comparison among TIRADS (ACR TI-RADS and KWAK- TI-RADS) and 2015 ATA guidelines in the diagnostic efficiency of thyroid nodules. Endocrine 2019;64:90-6. DOI: https://doi.org/10.1007/s12020-019-01843-x

23. Middleton WD, Teefey SA, Reading CC, et al. Comparison of performance characteristics of American College of Radiology TI-RADS, Korean Society of Thyroid Radiology TIRADS, and American Thyroid Association Guidelines. AJR Am J Roentgenol 2018;210:1148-54. DOI: https://doi.org/10.2214/AJR.17.18822

24. Kim PH, Suh CH, Baek JH, et al. Unnecessary thyroid nodule biopsy rates under four ultrasound risk stratification systems: a systematic review and meta-analysis. Eur Radiol 2021;31:2877-85. DOI: https://doi.org/10.1007/s00330-020-07384-6

25. Wu XL, Du JR, Wang H, et al. Comparison and preliminary discussion of the reasons for the differences in diagnostic performance and unnecessary FNAC biopsies between the ACR TIRADS and 2015 ATA guidelines. Endocrine 2019;65:121-31. DOI: https://doi.org/10.1007/s12020-019-01886-0

26. Chen H, Ye J, Song J, et al. Comparison of different ultrasound classification systems of thyroid nodules for identifying malignant potential: a cross-sectional study. Clinics (Sao Paulo) 2021;76:e2126. DOI: https://doi.org/10.6061/clinics/2021/e2126

27. Zhang WB, Xu HX, Zhang YF, et al. Comparisons of ACR TI-RADS, ATA guidelines, Kwak TI-RADS, and KTA/KSThR guidelines in malignancy risk stratification of thyroid nodules. Clin Hemorheol Microcirc 2020;75:219-32. DOI: https://doi.org/10.3233/CH-190778

28. Botha M, Kisansa M, Greeff W. American College of Radiology Thyroid Imaging Reporting and Data System standardises reporting of thyroid ultrasounds. SA J Radiol 2020;24:1804. DOI: https://doi.org/10.4102/sajr.v24i1.1804

29. Hoang JK, Middleton WD, Langer JE, et al. Comparison of thyroid risk categorization systems and fine-needle aspiration recommendations in a multi-institutional thyroid ultrasound registry. J Am Coll Radiol 2021;18:1605-13. DOI: https://doi.org/10.1016/j.jacr.2021.07.019

30. Mussoi de Macedo BM, Izquierdo RF, Golbert L, Souza Meyer EL. Reliability of Thyroid Imaging Reporting and Data System (TI-RADS), and ultrasonographic classification of the American Thyroid Association (ATA) in differentiating benign from malignant thyroid nodules. Arch Endocrinol Metab 2018;62:131-8.

31. Rosario PW, da Silva AL, Nunes MS, et al. Risk of malignancy in 1502 solid thyroid nodules >1 cm using the new ultrasonographic classification of the American Thyroid Association. Endocrine 2017;56:442-5. DOI: https://doi.org/10.1007/s12020-016-1163-7

32. Karaagac M, Sarigoz T, Ertan T, Topuz O. Evaluation of the Bethesda system and the ACR TIRADS in an endemic goiter region. Endocr Res 2020;45:226-32. DOI: https://doi.org/10.1080/07435800.2020.1799226

33. Ha SM, Baek JH, Na DG, et al. Diagnostic performance of practice guidelines for thyroid nodules: thyroid nodule size versus biopsy rates. Radiology 2019;291:92-9. DOI: https://doi.org/10.1148/radiol.2019181723

34. Yoon JH, Lee HS, Kim EK, et al. Malignancy risk stratification of thyroid nodules: comparison between the Thyroid Imaging Reporting and Data System and the 2014 American Thyroid Association management guidelines. Radiology 2016;278:917-24. DOI: https://doi.org/10.1148/radiol.2015150056

35. Ha EJ, Na DG, Baek JH, et al. US fine-needle aspiration biopsy for thyroid malignancy: diagnostic performance of seven society guidelines applied to 2000 thyroid nodules. Radiology 2018;287:893-900. DOI: https://doi.org/10.1148/radiol.2018171074

36. Middleton WD, Teefey SA, Tessler FN, et al. Analysis of malignant thyroid nodules that do not meet ACR TI-RADS criteria for fine-needle aspiration. AJR Am J Roentgenol 2021;216:471-8. DOI: https://doi.org/10.2214/AJR.20.23123

37. Castellana M, Castellana C, Treglia G, et al. Performance of five ultrasound risk stratification systems in selecting thyroid nodules for FNAC. J Clin Endocrinol Metab 2020;105:dgz170. DOI: https://doi.org/10.1210/clinem/dgz170

38. Gao L, Xi X, Wang J, et al. Ultrasound risk evaluation of thyroid nodules that are "unspecified" in the 2015 American Thyroid Association management guidelines: A retrospective study. Medicine (Baltimore) 2018;97:e13914. DOI: https://doi.org/10.1097/MD.0000000000013914

39. Ha EJ, Na DG, Moon WJ, et al. Diagnostic performance of ultrasound-based risk-stratification systems for thyroid nodules: comparison of the 2015 American Thyroid Association guidelines with the 2016 Korean Thyroid Association/Korean Society of Thyroid Radiology and 2017 American College of Radiology guidelines. Thyroid. 2018;28:1532-37. DOI: https://doi.org/10.1089/thy.2018.0094

40. Yang W, Fananapazir G, LaRoy J, et al. Can the American Thyroid Association, K-TIRADS and ACR-TIRADS ultrasound classification systems be used to predict malignancy in Bethesda category IV nodules? Endocr Pract 2020;26:945-52. DOI: https://doi.org/10.4158/EP-2020-0024

41. Grani G, Lamartina L, Ascoli V, et al. Ultrasonography scoring systems can rule out malignancy in cytologically indeterminate thyroid nodules. Endocrine 2017;57:256-61. DOI: https://doi.org/10.1007/s12020-016-1148-6

42. Goundan PN, Mamou J, Rohrbach D, et al, A preliminary study of quantitative ultrasound for cancer-risk assessment of thyroid nodules. Front Endocrinol (Lausanne) 2021;12:627698. DOI: https://doi.org/10.3389/fendo.2021.627698

43. Ruan JL, Yang HY, Liu RB, et al. Fine needle aspiration biopsy indications for thyroid nodules: compare a point-based risk stratification system with a pattern-based risk stratification system. Eur Radiol 2019;29:4871-8. DOI: https://doi.org/10.1007/s00330-018-5992-z