Clinical Utility of Shear Wave Elastography Patterns for Differentiating between Benign and Malignant Breast Lesions

ABSTRACT

PURPOSE: This retrospective study evaluated the utility of shear wave elastography (SWE), Tozaki's visual pattern classification, and conventional Breast Imaging Reporting and Data System (BI-RADS) classification for differentiating between benign and malignant lesions. METHODS: Between May 2015 and July 2016, 388 patients underwent SWE and B-mode ultrasonography. The BI-RADS system was used to exclude cases with category 1–2 lesions or unbiopsied category 3 lesions. A total of 100 patients with 100 solid breast masses underwent tissue sampling (ultrasonography-guided core biopsy or vacuum-assisted biopsy) or surgical excision. The quantitative elasticity was measured for each lesion, and the imaging and histological findings were compared. RESULTS: The mean age of the patients was 51 years (range, 18–79 years). Histological examination identified 50 malignant lesions and 50 benign lesions. According to the BI-RADS classification, 20 lesions were classified as category 3, 56 as category 4, and 24 as category 5. Based on the Tozaki classification, 39 lesions were classified as pattern 1, seven as pattern 2, 23 as pattern 3, and 31 as pattern 4. If patterns 1 and 2 were assumed to be benign, and patterns 3 and 4 were assumed to be malignant, the combination of BI-RADS and SWE provided a sensitivity of 100% (50/50), a specificity of 92.0% (46/50), a positive predictive value of 92.5% (50/54), and a negative predictive value of 100% (50/50). CONCLUSION: The combination of SWE and BI-RADS was useful for evaluating breast lesions, improved the specificity of ultrasonography and may help facilitate appropriate treatment planning.