Thyroid ultrasound (US) is a key examination for the management of thyroid nodules. Thyroid US is easily accessible, noninvasive, and cost-effective, and is a mandatory step in the workup of thyroid nodules. The main disadvantage of the method is that it is operator dependent. Thyroid US assessment of the risk of malignancy is crucial in patients with nodules, in order to select those who should have a fine needle aspiration (FNA) biopsy performed. Due to the pivotal role of thyroid US in the management of patients with nodules, the European Thyroid Association convened a panel of international experts to set up European guidelines on US risk stratification of thyroid nodules. Based on a review of the literature and on the American Association of Clinical Endocrinologists, American Thyroid Association, and Korean guidelines, the panel created the novel European Thyroid Imaging and Reporting Data System, called EU-TIRADS. This comprises a thyroid US lexicon; a standardized report; definitions of benign and low-, intermediate-, and high-risk nodules, with the estimated risks of malignancy in each category; and indications for FNA. Illustrated by numerous US images, the EU-TIRADS aims to serve physicians in their clinical practice, to enhance the interobserver reproducibility of descriptions, and to simplify communication of the results.
Gilles Russ, Steen J. Bonnema, Murat Faik Erdogan, Cosimo Durante, Rose Ngu, and Laurence Leenhardt
Alessia Cozzolino, Tiziana Filardi, Ilaria Simonelli, Giorgio Grani, Camilla Virili, Ilaria Stramazzo, Maria Giulia Santaguida, Pietro Locantore, Massimo Maurici, Daniele Gianfrilli, Andrea M Isidori, Cosimo Durante, and Carlotta Pozza
Context: Significant uncertainty exists about the diagnostic accuracy of ultrasonographic (US) features used to predict the risk of thyroid cancer in the pediatric population. Moreover, there are not specific indications for thyroid nodule evaluation in patients during the transition age.
Objective: The meta-analysis aimed to address the following question: which thyroid nodule US features have the highest accuracy in predicting malignancy in the transition age.
Methods: We performed a meta-analysis of observational/cohort/diagnostic accuracy studies dealing with thyroid nodule sonography, reporting US features, and using histology as reference standard for the diagnosis of malignancy and histology or cytology for the diagnosis of benignity in the transition age (mean/median age 12-21 years).
Results: The inclusion criteria were met by 14 studies, published between 2005 and 2020, including 1306 thyroid nodules (mean size 17.9 mm) from 1168 subjects. The frequency of thyroid cancer was 36.6%. The US features with the highest diagnostic odds ratio for malignancy were the presence of suspicious lymph nodes [DOR: 56.0 (95% CI: 26.0-119.0)], a “taller than wide” shape of the nodule [6.0 (95% CI: 2.0-16.0)], the presence of microcalcifications [13.0 (95% CI: 6.0-29.0)] and irregular margins [9.0 (95% CI: 5.0-17.0)]. Heterogeneity among the studies was substantial.
Conclusions: Following the diagnosis of a thyroid nodule in transition age, a thorough US examination of the neck is warranted. The detection of suspicious lymph nodes and/or thyroid nodules with a “taller than wide” shape, microcalcifications and irregular margins is associated with the highest risk of malignancy in the selection of nodules candidates to biopsy.
Giorgio Grani, Livia Lamartina, Valeria Ramundo, Rosa Falcone, Cristiano Lomonaco, Laura Ciotti, Martina Barone, Marianna Maranghi, Vito Cantisani, Sebastiano Filetti, and Cosimo Durante
Introduction: A taller-than-wide (TTW) shape is a suspicious feature of thyroid nodules commonly defined as an anteroposterior/transverse diameter (AP/T) ratio >1. An intraobserver variability of up to 18% in AP diameter evaluations has been described, which may lead to overreporting of this feature. To potentially improve the reliability of the TTW definition, we propose an arbitrary ratio of ≥1.2. Objective: The aim of this study was to estimate the impact of this definition on diagnostic performance. Methods: We prospectively analyzed 553 thyroid nodules referred for cytology evaluation at an academic center. Before fine-needle aspiration, two examiners jointly defined all sonographic features considered in risk stratification systems developed by the American Thyroid Association (ATA), the American Association of Clinical Endocrinologists (AACE), the American College of Radiology (ACR TIRADS), the European Thyroid Association (EU-TIRADS), and the Korean Society of Thyroid Radiology (K-TIRADS). TTW was defined according to the current definition (AP/T diameter ratio >1) and an arbitrary alternative definition (AP/T ratio >1.2). Results: The alternative definition classified fewer nodules as TTW (28, 5.1% vs. 94, 17%). The current and proposed definitions have a sensitivity of 26.2 and 11.9% (p = 0.03) and a specificity of 83.8 and 95.5% (p < 0.001). Thus, as a single feature, the arbitrary definition has a lower sensitivity and a higher specificity. When applied to sonographic risk stratification systems, however, the proposed definition would increase the number of avoided biopsies (up to 58.2% for ACR TIRADS) and the specificity of all systems, without negative impact on sensitivity or diagnostic odds ratio. Conclusions: Re-defining TTW nodules as those with an AP/T ratio ≥1.2 improves this marker’s specificity for malignancy. Using this definition in risk stratification systems will increase their specificity, reducing the number of suggested biopsies without significantly diminishing their overall diagnostic performance.