Shear-wave elastography as a tool in the assessment of thyroid nodules

Introduction: Shear-wave elastography (SWE) has been shown to be predictive of malignancy in thyroid nodules. Objective: To determine, by SWE, the stiffness cutoff point with the highest specificity and sensitivity to detect thyroid nodules that require surgery. Methods: Cross-sectional study of ultrasonographically-evaluated patients for thyroid nodules over a period of three years; the TI-RADS classification system was used, and nodule stiffness was determined by SWE. Histopathological specimens were classified using the Bethesda system, and the stiffness cutoff point with the highest specificity and sensitivity was obtained using ROC curves. Results: Forty-one percent of the nodules were classified as TI-RADS 5, and 59 %, as TI-RADS 1-4. In TI-RADS 5 nodules, median stiffness of those in Bethesda system IV-VI categories was 35.9 kPa; in nodules with TI-RADS 1-4, 21.6 kPa. In TI-RADS 5 nodules, a cutoff point > 32.5 kPa had a specificity of 75 % and sensitivity of 57 % to detect those requiring surgery; in TI-RADS 1 to 4 nodules, a cutoff point of 21.5 kPa had a specificity of 63 % and sensitivity of 51 %. Conclusion: SWE-determined stiffness is useful to detect nodules that require surgical evaluation.