Multicenter study to evaluate the difference between benign and malignant breast tumors by contrast-enhanced ultrasonography (JABTS FLOW-CEUS 01 study -part 2-)

Abstract

Background Contrast-enhanced ultrasonography (CEUS) of the breast using perflubutane (Sonazoid®) has been utilized for over 6 years in Japan. Owing to advances in equipment and technology, reevaluation of CEUS findings and diagnostic criteria is of importance. Therefore, in the present study, we examined the contrast patterns of benign and malignant lesions on CEUS (JABTS FLOW-CEUS01, UMINID: 000026289). Objective First, we aimed to select typical CEUS images of malignant and benign breast tumors. Second, we aimed to reevaluate the diagnostic criteria for CEUS of breast tumors. Methods Two hundred and eighteen breast tumors from nine institutions evaluated using CEUS and subsequently histological examinations were analyzed in the present study. After evaluation of 30 educational cases that were extracted from the registered cases, we proposed CEUS findings and criteria for the differential diagnosis of breast tumors. The remaining 188 cases were used for the analysis, and the diagnosis was made by three blind readers. In accordance with the new findings and criteria, the diagnostic accuracy of CEUS of breast tumors was evaluated. This study was approved by the ethics committee and institutional review board of Kobe City Nishi-Kobe Medical Center. Results The following CEUS findings were useful for the differential diagnosis: 5 contrast-enhancement patterns (shapes, margins, defects of stains, intensity, and homogeneity), 3 vascular patterns (tree-like appearance, surrounding marginal vessels, plunging or penetrating vessels), and range of contrast-enhanced areas. In the univariate analysis, all the 9 findings were significantly useful for the differential diagnosis. In the multivariate analysis, range of contrast-enhanced areas (odds ratio; 1.863, 95% confidence interval [CI] 1.356-2.560, p Conclusions The conventional CEUS findings and criteria of breast tumors were confirmed to be useful for differentiating between benign and malignant breast tumors. Additionally, range of contrast-enhanced areas was found to be helpful. Although the findings analyzed herein were characteristic CEUS features of benign and malignant breast tumors, respectively, additional diagnostic effects seem to be limited. Thus, it is important to select cases for which CEUS may be useful.