Clinical Application of Shear Wave Elastography in Breast Masses

Background: Quantitative shear wave elastography (SWE) has been developed and utilized to aid in the differentiation between benign and malignant breast lesions based on their stiffness. Objectives: The purpose of this study was to evaluate the clinical effects of the additional use of SWE to conventional ultrasound (US) according to the maximum (Emax) and mean (Emean) elasticitiy values. Patients and Methods: A total 115 patients with 133 lesions were assessed using conventional US and SWE. All patients underwent US-guided core needle biopsy or surgery, and the pathological results were used as reference standards. We compared the diagnostic values including sensitivities, specificities, positive predictive values (PPVs) and negative predictive values (NPVs) and accuracies of conventional US and SWE according to the E-max and E-mean values. Next, we obtained the optimal E-max and E-mean cutoff values for SWE. Using these cutoff values, we analyzed the clinical effects of the additional use of SWE to conventional US based on the corrected results. Results: Of the 133 breast lesions, 32 were malignant and 101 were benign. In the differentiation of benign and malignant lesions, conventional US resulted in sensitivity of 100 %, specificity of 43.0 %, PPV of 57.1 %, NPV of 36.7 %, and accuracy of 100 %. Regarding SWE, the sensitivity, specificity, PPV, NPV, and accuracy values based on E-max were 84.4 %, 89.1 %, 71.1 %, 94.7 %, and 88.0 %, respectively, and the corresponding values based on E-mean were 84.8 %, 93.0 %, 91.0 %, 80.0 %, and 94.9 %, respectively. The optimal E-max and E-mean cutoff values were 81.3 and 60.7 kPa, respectively. However, there was no significant difference between E-max and E-mean. The corrected results related to the additional use of SWE to conventional US indicated 97.0 % sensitivity, 93.0 % specificity, 82.1 % PPV, 98.9 % NPV, and 94.0 % accuracy (P < 0.0001). Conclusion: The additional use of SWE to conventional US resulted in marked improvements in specificity, PPV, and accuracy and slight diminutions in sensitivity and NPV for the differentiation benign and malignant breast lesions. Both E-max and E-mean were effective diagnostic parameters, and there was no significant difference between these two parameters.