International Expert Consensus on US Lexicon for Thyroid Nodules.

Multiple US-based systems for risk stratification of thyroid nodules are in use worldwide. Unfortunately, the malignancy probability assigned to a nodule varies, and terms and definitions are not consistent, leading to confusion and making it challenging to compare study results and craft revisions. Consistent application of these systems is further hampered by interobserver variability in identifying the sonographic features on which they are founded. In 2018, an international multidisciplinary group of 19 physicians with expertise in thyroid sonography (termed the International Thyroid Nodule Ultrasound Working Group) was convened with the goal of developing an international system, tentatively called the International Thyroid Imaging Reporting and Data System, or I-TIRADS, in two phases: (phase I) creation of a lexicon and atlas of US descriptors of thyroid nodules and (phase II) development of a system that estimates the malignancy risk of a thyroid nodule. This article presents the methods and results of phase I. The purpose herein is to show what has been accomplished thus far, as well as generate interest in and support for this effort in the global thyroid community.

Development of sentinel lymph node biopsy technique in patients with salivary gland cancer using the IDEAL framework.

BACKGROUND: Salivary cancer is rare and comprises a variety of histological subtypes and clinical behaviors. There is no agreed method of estimating the risk of occult metastasis or managing the clinically N0 neck.Sentinel node biopsy (SNB) may offer a solution but previous studies have not produced a reliable imaging protocol. This study uses novel technology and trial methodology to develop a reliable SNB technique, with primary aim to identify peri-and intraglandular sentinel nodes. METHODS: IDEAL framework was used to undertake SNB in clinically node negative salivary gland cancer. Patients with cT1-2 N0 salivary cancer were eligible. Lymphoscintigraphy was undertaken using Tc-99 m labelled nanocoll. Injection technique as well as adjunctive use of freehand SPECT (fhSPECT), near-infrared (NIR) fluorescence imaging, and navigation-guided surgery were used and optimisied during the study protocol. RESULTS: 10 patients were recruited. Initial protocol of peritumoural injection of Tc99 m nanocoll showed poor image resolution. Subsequent adjustment to single intratumoural injection allowed identification of intraglandular sentinel nodes. Fh/SPECT and NIR fluorescence imaging found intraglandular lymph nodes otherwise not recognizable to the naked eye. In two cases occult lymph node metastasis were identified. CONCLUSION: This study has shown the IDEAL framework is vital in allowing iterative changes in surgical protocol in the light of experience. This study has produced a reliable method for detection of sentinel nodes, in particular the ability to identify intra- and periglandular nodes with diagnosis of occult metastatic deposits and no false negative results. Our protocol can be readily transferred in to larger scale studies.

Performance of EU-TIRADS in malignancy risk stratification of thyroid nodules: a meta-analysis.

OBJECTIVE: Several thyroid imaging reporting and data systems (TIRADS) have been proposed to stratify the malignancy risk of thyroid nodule by ultrasound. The TIRADS by the European Thyroid Association, namely EU-TIRADS, was the last one to be published. DESIGN: We conducted a meta-analysis to assess the prevalence of malignancy in each EU-TIRADS class and the performance of EU-TIRADS class 5 vs 2, 3 and 4 in detecting malignant lesions. METHODS: Four databases were searched until December 2019. Original articles reporting the performance of EU-TIRADS and adopting histology as reference standard were included. The number of malignant nodules in each class and the number of nodules classified as true/false positive/negative were extracted. A random-effects model was used for pooling data. RESULTS: Seven studies were included, evaluating 5672 thyroid nodules. The prevalence of malignancy in each EU-TIRADS class was 0.5% (95% CI: 0.0-1.3), 5.9% (95% CI: 2.6-9.2), 21.4% (95% CI: 11.1-31.7), and 76.1% (95% CI: 63.7-88.5). Sensitivity, specificity, PPV, NPV, LR+, LR- and DOR of EU-TIRADS class 5 were 83.5% (95% CI: 74.5-89.8), 84.3% (95% CI: 66.2-93.7), 76.1% (95% CI: 63.7-88.5), 85.4% (95% CI: 79.1-91.8), 4.9 (95% CI: 2.9-8.2), 0.2 (95% CI: 0.1-0.3), and 24.5 (95% CI: 11.7-51.0), respectively. A further improved performance was found after excluding two studies because of limited sample size and low prevalence of malignancy in class 5. CONCLUSIONS: A limited number of studies generally conducted using a retrospective design was found. Acknowledging this limitation, the performance of EU-TIRADS in stratifying the risk of thyroid nodules was high. Also, EU-TIRADS class 5 showed moderate evidence of detecting malignant lesions.

A multicentre validation study for the EU-TIRADS using histological diagnosis as a gold standard.

OBJECTIVE: Many systems for risk stratification of thyroid nodule with ultrasound (US) have been proposed and the EU-TIRADS issued by the ETA in 2017 was the last to have been published. The present study was undertaken to evaluate whether the malignancy risk of each category corresponded to the given range of the guidelines and assess the diagnostic value of EU-TIRADS in a multi-institutional trial with histology as gold standard. DESIGN: Three institutions in Switzerland, France and United Kingdom shared this retrospective study. Enrolment period was 2013-2017. Included were patients who had undergone surgery with a detailed preoperative thyroid US. METHODS: Cancer risk was calculated for each EU-TIRADS score. Predictivity tests were estimated. Nonparametric statistical analysis was used. RESULTS: The final series included 1058 nodules of which 257 (24.3%) carcinomas. Nodules were classified as EU-TIRADS 2, 3, 4 and 5 in 6.7, 46.4, 26.2 and 20.7%, respectively. Cancer prevalence was 1.4, 3.5, 17 and 87.7% in classes 2-5, respectively (P < 0.0001). EU-TIRADS 5 had a significantly higher cancer rate than the other summed categories (7.7%; P < 0.0001) with OR 84.7. When EU-TIRADS 4 and 5 were combined, 93% sensitivity and 97% NPV were found and findings of the three institutions were quite similar. Using the recommended criteria for FNA negative predictive value was 90.9%. CONCLUSIONS: The cancer rate was within or close to the given range described in the EU-TIRADS guidelines. The diagnostic value was satisfactory. The results were similar in the three institutions participating in the study.

European Thyroid Association Guidelines for Ultrasound Malignancy Risk Stratification of Thyroid Nodules in Adults: The EU-TIRADS.

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.