The Potential of Shear Wave Elastography to Reduce Unnecessary Biopsies in Breast Cancer Diagnosis: An International, Diagnostic, Multicenter Trial

Purpose In this prospective, multicenter trial we evaluated whether additional shear wave elastography (SWE) for patients with BI-RADS 3 or 4 lesions on breast ultrasound could further refine the assessment with B-mode breast ultrasound for breast cancer diagnosis. Materials and Methods We analyzed prospective, multicenter, international data from 1288 women with breast lesions rated by conventional 2D B-mode ultrasound as BI-RADS 3 to 4c and undergoing 2D-SWE. After reclassification with SWE the proportion of undetected malignancies should be <2%. All patients underwent histopathologic evaluation (reference standard). Results Histopathologic evaluation showed malignancy in 368 of 1288 lesions (28.6%). The assessment with B-mode breast ultrasound resulted in 1.39% (6 of 431) undetected malignancies (malignant lesions in BI-RADS 3) and 53.80% (495 of 920) unnecessary biopsies (biopsies in benign lesions). Re-classifying BI-RADS 4a patients with a SWE cutoff of 2.55m/s resulted in 1.98% (11 of 556) undetected malignancies and a reduction of 24.24% (375 vs. 495) of unnecessary biopsies. Conclusion A SWE value below 2.55m/s for BI-RADS 4a lesions could be used to downstage these lesions to follow-up, and therefore reduce the number of unnecessary biopsies by 24.24%. However, this would come at the expense of some additionally missed cancers compared to B-mode breast ultrasound (rate of undetected malignancies 1.98%, 11 of 556, versus 1.39%, 6 of 431) which would, however, still be in line with the ACR BI-RADS 3 definition (<2% of undetected malignancies).