Influence of lesion size on differential diagnosis of benign and malignant breast lesions by real-time two-dimensional shear wave elastography

Background: The aim of this study was to evaluate the influence of lesion size on the performance of real-time two-dimensional shear wave elastography (2D-SWE) in the diagnosis of breast lesions. Materials and Methods: A total of 118 consecutive female patients with 129 breast lesions (50 malignant and 79 benign) who underwent surgical excision and/or core biopsy were studied. The lesions were categorized into three subgroups according to their size: (1) group 1: < 1.0 cm3; (2) group 2: 1.0-4.0 cm3; (3) group 3: > 4.0 cm3. The maximum elasticity (Emax), mean elasticity (Emean), and their standard deviation (SD) in the three subgroups were compared and analyzed in terms of the cutoff values acquired by pathological results. Results: The lesion size significantly differed between benign and malignant masses (P < 0.05). Malignant lesions exhibited significantly elevated values of Emax, Emean, and SD, compared with benign lesions in the three subgroups. The optimal threshold was higher for larger malignant and benign lesions (P < 0.05). In malignant lesions, the SWE parameters in group 1 were significantly different from those in groups 2 and 3. The area under the receiver operating characteristics curve (AUROC) of SD was higher than that of Emax and Emean in all three subgroups. Conclusion: The values of 2D-SWE parameters increase with the increase in size of a breast mass, and the adjustment of the threshold based on lesion size yields a more accurate diagnosis. Among the SWE parameters, SD has the best diagnostic performance.