Shear Wave Elastography and Thyroid Imaging Reporting and Data System (TIRADS) for the Risk Stratification of Thyroid Nodules—Results of a Prospective Study

Manuela Petersen,Simone A. Schenke,Roland S. Croner,Jonas Firla,Michael C. Kreissl

doi:10.3390/diagnostics12010109

Abstract

Purpose: To compare the diagnostic performance of thyroid imaging reporting and data system (TIRADS) in combination with shear wave elastography (SWE) for the assessment of thyroid nodules. Methods: A prospective study was conducted with the following inclusion criteria: preoperative B-mode ultrasound (US) including TIRADS classification (Kwak-TIRADS, EU-TIRADS), quantitative SWE and available histological results. Results: Out of 43 patients, 61 thyroid nodules were detected; 10 nodules were found to be thyroid cancer (7 PTC, 1 FTC, 2 HüCC) and 51 were benign. According to Kwak-TIRADS the majority of benign nodules (47 out of 51, 92.2%) were classified in the low-risk- and intermediate-risk class, four nodules were classified as high-risk (7.8%). When using EU-TIRADS, the benign nodules were distributed almost equally across all risk classes, 21 (41.2%) nodules were classified in the low-risk class, 16 (31.4%) in the intermediate-risk class and 14 (27.4%) in the high-risk class. In contrast, most of the malignant nodules (eight out of ten) were classified as high-risk on EU-TIRADS. One carcinoma was classified as low-risk and one as intermediate-risk nodule. For SWE, ROC analysis showed an optimal cutoff of 18.5 kPa to distinguish malignant and benign nodules (sensitivity 80.0%, specificity 49.0%, PPV 23.5% and NPV 92.6%). The addition of elastography resulted in an increase of accuracy from 65.6% to 82.0% when using Kwak-TIRADS and from 49.2% to 72.1% when using EU-TIRADS. Conclusion: Our data demonstrate that the combination of TIRADS and SWE seems to be superior for the risk stratification of thyroid nodules than each method by itself. However, verification of these results in a larger patient population is mandatory.

Highlights

For a number of years, there has been an intense debate, especially in Germany, whether surgeries for thyroid nodules are unnecessarily performed
Gray-scaled ultrasound is excellent for the detection and characterization of thyroid nodules, but the accuracy for the differentiation between benign and malignant lesions based on single criteria, such as hypoechogenicity, microcalcification and a taller-than-wide shape is low [6,7]
The objective of our study was to evaluate the diagnostic performance of shear wave elastography (SWE) and thyroid imaging reporting and data system (TIRADS) according to Kwak et al and EU-TIRADS alone and in combination for the assessment of thyroid nodules [12,14]

Summary

Introduction

For a number of years, there has been an intense debate, especially in Germany, whether surgeries for thyroid nodules are unnecessarily performed. A thyroidectomy is often performed for (supposedly benign) nodular goiter [2]. This is why thyroid specialists call for improvements in preoperative diagnostics [3,4]. The majority of thyroid nodules are incidental findings discovered by imaging examinations for reasons unrelated to the thyroid [5]. Different research groups developed US-based tools for stratifying the risk of malignancy of thyroid nodules because of a constellation or a number of suspicious ultrasound features, known as the thyroid imaging reporting and data system (TIRADS) [8,9,10,11,12,13,14]

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Methods

Results

Discussion

Conclusion