Evaluation of the diagnostic function of shear wave elastography in the differentiation of malignant and benign breast masses and its relationship with histological factors

Background: Shear wave elastography (SWE) estimates the stiffness of a mass based on the velocity of shear wave propagation by sound waves. Due to higher cell density and angiogenesis, malignant masses have higher stiffness than benign ones. Methods: The present study was a prospective study and was performed on patients who were referred to Ahvaz Golestan Hospital with breast mass during March 2020 to March 2021. Only patients with 4-5 BI-RAD were evaluated. Patients were graded based on ACR BI-RAD. All patients were subjected to ultrasound and selection of BI-RAD 4-5 patients for evaluation with SWE and sampling for pathology testing. In this study, in order to increase the maximum accuracy and take samples from the main location of the lesion, sampling was done by ultrasound-guided biopsy method. Tumor information was recorded by a specialist doctor after ultrasound and SWE. This information included tumor type, tumor size and grade, presence of metastasis, involvement of lymph nodes, average and maximum elasticity. SWE cutoffs were compared for mean and maximum elasticity to distinguish benign from malignant masses. Results: In this study, 115 patients were evaluated. 63.5% (73) of the patients had benign mass and 36.5% (42) had malignant ones. There was a significant relationship between tumor size and mean and maximum elasticity (P<0.001 The results showed that the diagnostic accuracy of SWE in identifying malignant masses compared to benign ones was 100%, so that the mean (16.61±8.03 kPa) and maximum (21.14±8.88 kPa) elasticity in benign masses were significantly lower than the mean (32.21±7.59 kPa) and maximum (91.62±8.84 kPa) elasticity of malignant masses (P<0.001). There was also a significant difference between the 4 BI-RAD subgroups, so that in BI-RAD 4a, the lowest mean and maximum elasticity were seen (P<0.001). Conclusion: The results showed that SWE parameters have sufficient diagnostic accuracy in diagnosing malignant breast masses. Therefore, the use of quantitative SWE parameters in conjunction with ultrasound and BI-RADS classification can avoid unnecessary biopsies.