Efficacy of contrast-enhanced EUS for lymphadenopathy: a prospective multicenter pilot study (with videos)

Abstract

Background and aims: Contrast-enhanced EUS (CE-EUS) allows qualitative and quantitative evaluation based on real-time perfusion imaging and may improve the diagnostic capability. The aim of this study was to evaluate the efficacy of CE-EUS in differentiating malignant from benign lymphadenopathy.

Methods: Patients undergoing EUS-FNA for abdominal or mediastinal lymphadenopathy were prospectively enrolled. The echofeatures on B-mode EUS and the vascular and enhancement patterns in CE-EUS were qualitatively evaluated. The echo intensity change during 60 seconds in the lymphadenopathy was quantitatively evaluated by time intensity curve (TIC) analysis.

Results: One hundred consecutive patients with 70 malignant and 30 benign lesions were enrolled. The sensitivity, specificity, and accuracy of the qualitative assessment in B-mode EUS were 77%, 17%, and 59%, respectively. When the heterogeneous enhancement was defined as malignancy, the sensitivity, specificity, and accuracy of the qualitative assessment in CE-EUS were 67%, 87%, and 73%, respectively. In TIC analysis, the velocity of reduction for homogeneous lesions showed a significant difference between malignant and benign lesions (P = .0011), and the receiver operating characteristic analysis showed an optimal cut-off value of .149 dB/s. The sensitivity, specificity, and diagnostic capabilities of CE-EUS for malignancy were improved to 89%, 77%, and 85%, respectively, on combining the qualitative and quantitative analyses. With regard to diagnostic accuracy, CE-EUS with combined qualitative and quantitative analyses was significantly higher than those of B-mode EUS or qualitative assessment of CE-EUS.

Conclusions: CE-EUS with the combined qualitative and quantitative analyses for lymphadenopathy might be useful to complement regular EUS and EUS-FNA. (Clinical trial registration number: UMIN000024298.).