Endocrine Abstracts

Introduction: Work-up of thyroid nodules remains challenging. At present, many patients with thyroid nodules are referred to surgery for diagnostic rather than therapeutic purposes. Therefore, the value of non-invasive diagnostic methods to optimize the selection of patients for surgery is needed. Strain elastography (SE) enables the determination of tissue elasticity and has shown promising results for the differentiation of thyroid nodules.

Methods: The aim of the present study was to evaluate the value of SE in a prospective multicentre study. A sample size calculation was performed when planning the study and the study was registered at clinical-trials.com. The study was approved by the local ethical committees of all participating centres, and written informed consent was obtained from all patients. All patients received an ultrasound (US) of the thyroid gland including colour doppler US and TIRADS classification. In addition all nodules were evaluated by strain elastography (Hitachi Medical System) using qualitative image interpretation of colour distribution (elastography score (ES) 1–4), strain value and strain ratio. Cytology and/or histology was used as reference method for all benign and histology only for all malignant nodules.

Results: Overall, 604 patients with 659 thyroid nodules (570 benign, 89 malignant) from six centres across Germany were included in the final analysis. Sensitivity, specificity, NPV, PPV, +LR were 22%, 74%, 86%, 11%, 0.8 for colour Doppler vascularization pattern 3–4; 79%, 40%, 92%, 17%, 1.3 for TIRADS; 69%, 74%, 92%, 36%, 2.66 for SE-ES; 58%, 81%, 92%, 32%, 3.0 for SE-strain value (cut-off 0.165); 60%, 78%, 92%, 31%, 2.7 for SE- strain ratio (cut-off 0.376), respectively. The diagnostic accuracies were 70% for TIRADS, 75% for SE-ES, 72% for SE-strain value, and 71% for strain ratio, respectively. No significant difference was found between these diagnostic accuracies.

Conclusions: Strain elastography as an additional ultrasound tool improves the diagnostic value of ultrasound for the exclusion of malignant thyroid nodules. Qualitative and semiquantitative elastography scores are comparably good.

Disclosure: This work was supported by Hitachi Medical Systems by providing ultrasound machines to some participating centers.