This paper has only examined the ACR TIRADS system, noting that other similar systems exist such as Korean TIRADS [14]and EU TIRADS [15]. However, these assumptions have intentionally been made to favor the expected performance of ACR-TIRADS, and so in real life ACR-TIRADS can be expected to perform less well than we have illustrated. 7. Second, we then apply TIRADS across all 5 nodule categories to give an idea how TIRADS is likely to perform overall. For TIRADS to add clinical value, it would have to clearly outperform the comparator (random selection), particularly because we have made some assumptions that favor TIRADS performance. The prevalence of incidental thyroid cancer at autopsy is around 10% [3]. Because the data set prevalence of thyroid cancer was 10%, compared with the generally accepted lower real-world prevalence of 5%, one can reasonably assume that the actual cancer rate in the ACR TIRADS categories in the real world would likely be one-half that quoted from the ACR TIRADS data set, which we illustrate in the following section. With the right blood tests, you can see if you have a thyroid nodule, and if so, you can treat it with radioactive iodine. Of note, we have not taken into account any of the benefits, costs, or harms associated with the proposed US follow-up of nodules, as recommended by ACR-TIRADS. Castellana M, Castellana C, Treglia G, Giorgino F, Giovanella L, Russ G, Trimboli P. Oxford University Press is a department of the University of Oxford. Keywords: Results: Among the 228 C-TIRADS 4 nodules, 69 were determined as C-TIRADS 4a, 114 were C-TIRADS 4b, and 45 were C-TIRADS 4c. Check for errors and try again. Very probably benign nodules are those that are both. Anderson TJ, Atalay MK, Grand DJ, Baird GL, Cronan JJ, Beland MD. The data set was 92% female and the prevalence of cancerous thyroid nodules was 10.3% (typical of the rate found on histology at autopsy, and double the 5% rate of malignancy in thyroid nodules typically quoted in the most relevant literature). Attempts to compare the different TIRADS systems on data sets that are also not reflective of the intended test population are similarly flawed (eg, malignancy rates of 41% [29]). Most thyroid nodules aren't serious and don't cause symptoms. A total of 228 thyroid nodules (C-TIRADS 4) were estimated by CEUS. The performance of any diagnostic test in this group has to be truly exceptional to outperform random selection and accurately rule in or rule out thyroid cancer in the TR3 or TR4 groups. The CEUS-TIRADS combining CEUS analysis with C-TIRADS could make up for the deficient sensibility of C-TIRADS, showing a better diagnostic performance than US and CEUS. Those working in this field would gratefully welcome a diagnostic modality that can improve the current uncertainty. The ACR TIRADS management flowchart also does not take into account these clinical factors. Current thyroid cancer trends in the United States, Association between screening and the thyroid cancer epidemic in South Korea: evidence from a nationwide study, 2015 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 ultrasound and the increase in diagnosis of low-risk thyroid cancer, Korean Society of Thyroid Radiology (KSThR) and Korean Society of Radiology, Ultrasonography diagnosis and imaging-based management of thyroid nodules: revised Korean Society of Thyroid Radiology Consensus Statement and Recommendations, European Thyroid Association Guidelines for Ultrasound Malignancy Risk Stratification of Thyroid Nodules in Adults: the EU-TIRADS, Multiinstitutional analysis of thyroid nodule risk stratification using the American College of Radiology Thyroid Imaging Reporting and Data System, The Bethesda System for reporting thyroid cytopathology: a meta-analysis, The role of repeat fine needle aspiration in managing indeterminate thyroid nodules, The indeterminate thyroid fine-needle aspiration: experience from an academic center using terminology similar to that proposed in the 2007 National Cancer Institute Thyroid Fine Needle Aspiration State of the Science Conference. Therefore, taking results from this data set and assuming they would apply to the real-world population raises concerns. EU-TIRADS 1 category refers to a US examination where no thyroid nodule is found; there is no need for FNAB. Advances in knowledge: The study suggests TIRADS and thyroid nodule size as sensitive predictors of malignancy. 1. Would you like email updates of new search results? The Thyroid Imaging Reporting and Data System (TI-RADS) of the American College of Radiology (ACR) was designed in 2017 with the intent to decrease biopsies of benign nodules and improve overall . It helps to decide if a thyroid nodule is benign or malignant by combining multiple features on ultrasound. Third, when moving on from the main study in which ACR TIRADS was developed [16] to the ACR TIRADS white paper recommendations [22], the TIRADS model changed by the addition of a fifth US characteristic (taller than wide), plus the addition of size cutoffs. Metab. Thyroid Tirads 4: Thyroid lesions with suspicious signs of malignancy. Diagnostic approach to and treatment of thyroid nodules. The CEUS-TIRADS category was 4c. The nodules were scored, measured and assigned to one of five TI-RADS levels (TR): TR1 - benign, TR2 - not suspicious, TR3 - mildly suspicious, TR4 - moderately suspicious, TR5 - highly suspicious. That particular test is covered by insurance and is relatively cheap. The category definitions were similar to BI-RADS, based on the risk of malignancy depending on the presence of suspicious ultrasound features: The following features were considered suspicious: The study included only nodules 1 cm in greatest dimension. The more carefully one looks for incidental asymptomatic thyroid cancers at autopsy, the more are found [4], but these do not cause unwellness during life and so there is likely to be no health benefit in diagnosing them antemortem. The following article describes the initial iterations proposed by individual research groups, none of which gained widespread use. Using TR5 as a rule-in test was similar to random selection (specificity 89% vs 90%). 2021 Dec 7;101(45):3748-3753. doi: 10.3760/cma.j.cn112137-20210401-00799. If one accepts that the pretest probability of a patient presenting with a thyroid nodule having an important thyroid cancer is 5%, then clinicians who tell every patient they see that they do not have important thyroid cancer will be correct 95% of the time. In a clinical setting, this would typically be an unselected sample of the test population, for example a consecutive series of all patients with a thyroid nodule presenting to a clinic, ideally across multiple centers. Whereas using TIRADS as a rule-in cancer test would be the finding that a nodule is TR5, with a sufficiently high chance of cancer that further investigations are required, compared with being TR1-4. Clinical Application of C-TIRADS Category and Contrast-Enhanced Ultrasound in Differential Diagnosis of Solid Thyroid Nodules Measuring 1 cm. Performance of Contrast-Enhanced Ultrasound in Thyroid Nodules: Review of Current State and Future Perspectives. Unauthorized use of these marks is strictly prohibited. 2009;94 (5): 1748-51. After repeat US-guided FNA, some patients achieve a cytological diagnosis, but typically two-thirds remain indeterminate [18], accounting for approximately 20% of initial FNAs (eg, 10%-30% [12], 31% [19], 22% [20]). This is a specialist doctor who specializes in the treatment and diagnosis of thyroid cancer. There are even data showing a negative correlation between size and malignancy [23]. The summary of test performance of random selection, ACR TIRADS as a rule-out test, ACR TIRADS as a rule-in test, and ACR TIRADS applied across all TIRADS categories are detailed in Table 2, and the full data, definitions, and calculations are given elsewhere [25]. We are here imagining the consequence of 100 patients presenting to the thyroid clinic with either a symptomatic thyroid nodule (eg, a nodule apparent to the patient from being palpable or visible) or an incidentally found thyroid nodule. A 35-year-old woman with a nodule in the left-lobe of her thyroid gland. The probability of malignancy was based on an equation derived from 12 features 2. Thyroid nodules come to clinical attention when noted by the patient; by a clinician during routine physical examination; or during a radiologic procedure, such as carotid ultrasonography, neck or chest computed tomography (CT), or positron emission tomography (PET) scanning. For example, a previous meta-analysis of more than 25,000 FNAs showed 33% were in these groups [17]. Some cancers would not show suspicious changes thus US features would be falsely reassuring. Sometimes a physician may refer you to a specialist (doctor) at a clinic that specializes in thyroid cancer. TIRADS Management Guidelines in the Investigation of Thyroid Nodules; Illustrating the Concerns, Costs, and Performance TIRADS Management Guidelines in the Investigation of Thyroid Nodules; Illustrating the Concerns, Costs, and Performance J Endocr Soc. Authors Tiantong Zhu 1 , Jiahui Chen 1 , Zimo Zhou 2 , Xiaofen Ma 1 , Ying Huang 1 Affiliations Thyroid nodules are solid or fluid-filled lumps that form within your thyroid, a small gland located at the base of your neck, just above your breastbone. We have detailed the data set used for the development of ACR TIRADS [16] in Table 1, plus noted the likely cancer rates in the real world if one assumes that the data set cancer prevalence (10.3%) is double that in the population upon which the test is intended to be used (pretest probability of 5%). To find 16 TR5 nodules requires 100 people to be scanned (assuming for illustrative purposes 1 nodule per scan). These nodules are relatively common and are usually harmless, but there is a very low risk of thyroid cancer. Applying ACR-TIRADS across all nodule categories did not perform well, with sensitivity and specificity between 60% and 80% and overall accuracy worse than random selection (65% vs 85%). Thus, the absolute risk of missing important cancer goes from 4.5% to 2.5%, so NNS=100/2=50. J. Endocrinol. [The diagnostic performance of 2020 Chinese Ultrasound Thyroid Imaging Reporting and Data System in thyroid nodules]. HHS Vulnerability Disclosure, Help Using TR1 and TR2 as a rule-out test had excellent sensitivity (97%), but for every additional person that ACR-TIRADS correctly reassures, this requires >100 ultrasound scans, resulting in 6 unnecessary operations and significant financial cost. These patients are not further considered in the ACR TIRADS guidelines. The diagnostic performance of CEUS-TIRADS was significantly better than CEUS and C-TIRADS. -, Lee JH, Shin SW. Overdiagnosis and Screening for Thyroid Cancer in Korea. The high prevalence of thyroid nodules combined with the generally indolent growth of thyroid cancer present a challenge for optimal patient care. The area under the curve was 0.803. Eur. Any additional test has to perform exceptionally well to surpass this clinicians 95% negative predictive performance, without generating false positive results and consequential harm. There are two suspicious signs with the nodule (solid and irregular margin) and it was defined as C-TIRADS 4b. Any test will struggle to outperform educated guessing to rule out clinically important thyroid cancer. In ACR TI-RADS, points in five feature categories are summed to determine a risk level from TR1 to TR5 . Until TIRADS is subjected to a true validation study, we do not feel that a clinician can currently accurately predict what a TIRADS classification actually means, nor what the most appropriate management thereafter should be. In 2009, Park et al. If the nodule got a score of more than 2 in the CEUS schedule, CEUS-TIRADS added 1 category. I have some serious news about my thyroid nodules today. The most common reason for our diagnosis is the thyroid nodule, a growth that often develops on the thyroid, the organ that controls our metabolism. The test that really lets you see a nodule up close is a CT scan. Noticeably benign pattern (0% risk of malignancy) TI-RADS 3: Probably benign nodules (<5% risk of malignancy) TI-RADS 4: 4a - Undetermined nodules (5-10% risk of malignancy) Score of 1. J Med Imaging Radiat Oncol (2009) 53(2):17787. However, the ACR TIRADS flow chart with its sharp cutoffs conveys a degree of certainty that may not be valid and may be hard for the clinician to resist. The results were compared with histology findings. The 2 examples provide a range of performance within which the real test performance is likely to be, with the second example likely to provide TIRADS with a more favorable test performance than in the real world. no financial relationships to ineligible companies to disclose. If it performs well enough, then the test is applied to a training set of data to better establish performance characteristics. 1 Most thyroid nodules are detected incidentally when imaging is performed for another indication. Other similar systems are in use internationally (eg, Korean-TIRADS [14] and EU-TIRADS [15]). Given that ACR TIRADS test performance is at its worst in the TR3 and TR4 groups, then the cost-effectiveness of TIRADS will also be at its worst in these groups, in particular because of the false-positive TIRADS results. Clinicians should be using all available data to arrive at an educated estimate of each patients pretest probability of having clinically significant thyroid cancer and use their clinical judgment to help advise each patient of their best options. Become a Gold Supporter and see no third-party ads. The arrival time, enhancement degree, enhancement homogeneity, enhancement pattern, enhancement ring, and wash-out time were analyzed in CEUS for all of the nodules. If you do 100 (or more) US scans on patients with a thyroid nodule and apply the ACR TIRADS management guidelines for FNA, this results in costs and morbidity from the resultant FNAs and the indeterminate results that are then considered for diagnostic hemithyroidectomy. A recent meta-analysis comparing different risk stratification systems included 13,000 nodules, mainly from retrospective studies, had a prevalence of cancer of 29%, and even in that setting the test performance of TIRADS was disappointing (eg, sensitivity 74%, specificity 64%, PPV 43%, NPV 84%), and similar to our estimated values of TIRADS test performance [38]. Search for other works by this author on: University of Otago, Christchurch School of Medicine, Department of Endocrinology, St Vincents University Hospital, Department of Radiology, St Vincents University Hospital, Dublin 4 and University College Dublin, Biostatistician, Department of Medical & Womens Business Management, Canterbury District Health Board, Thyroid incidentalomas: management approaches to nonpalpable nodules discovered incidentally on thyroid imaging, The prevalence of thyroid nodules and an analysis of related lifestyle factors in Beijing communities, Prevalence of differentiated thyroid cancer in autopsy studies over six decades: a meta-analysis, Occult papillary carcinoma of the thyroid. TI-RADS 2: Benign nodules. Given that a proportion of thyroid cancers are clinically inconsequential, the challenge is finding a test that can effectively rule-in or rule-out important thyroid cancer (ie, those cancers that will go on to cause morbidity or mortality). Objectives: Thyroid nodules with TIRADS 4 and 5 and diameter lower than 12 mm, are highly suspicious for malignancy and should be considered as indications for fine needle aspiration biopsy. A study that looked at all nodules in consecutive patients (eg, perhaps FNA of every nodule>10 mm) would be required to get an accurate measure of the cancer prevalence in those nodules that might not typically get FNA. 5. They are found . Outlook. Cibas ES, Ali SZ; NCI Thyroid FNA State of the Science Conference. NCI Thyroid FNA State of the Science Conference, The Bethesda System for reporting thyroid cytopathology, ACR Thyroid Imaging, Reporting and Data System (TI-RADS): white paper of the ACR TI-RADS Committee, Thyroid nodule size at ultrasound as a predictor of malignancy and final pathologic size, Impact of nodule size on malignancy risk differs according to the ultrasonography pattern of thyroid nodules, TIRADS management guidelines in the investigation of thyroid nodules; an illustration of the concerns, costs and performance, Thyroid nodules with minimal cystic changes have a low risk of malignancy, [The Thyroid Imaging Reporting and Data System (TIRADS) for ultrasound of the thyroid], Malignancy risk stratification of thyroid nodules: comparison between the Thyroid Imaging Reporting and Data System and the 2014 American Thyroid Association Management Guidelines, Validation and comparison of three newly-released Thyroid Imaging Reporting and Data Systems for cancer risk determination, Machine learning-assisted system for thyroid nodule diagnosis, Automatic thyroid nodule recognition and diagnosis in ultrasound imaging with the YOLOv2 neural network, Using artificial intelligence to revise ACR TI-RADS risk stratification of thyroid nodules: diagnostic accuracy and utility, A multicentre validation study for the EU-TIRADS using histological diagnosis as a gold standard, Comparison among TIRADS (ACR TI-RADS and KWAK- TI-RADS) and 2015 ATA Guidelines in the diagnostic efficiency of thyroid nodules, Prospective validation of the ultrasound based TIRADS (Thyroid Imaging Reporting And Data System) classification: results in surgically resected thyroid nodules, Diagnostic performance of practice guidelines for thyroid nodules: thyroid nodule size versus biopsy rates, Comparison of performance characteristics of American College of Radiology TI-RADS, Korean Society of Thyroid Radiology TIRADS, and American Thyroid Association Guidelines, Performance of five ultrasound risk stratification systems in selecting thyroid nodules for FNA. A minority of these nodules are cancers. The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS).