Value of Contrast-Enhanced Ultrasonography in the Differential Diagnosis of Enlarged Lymph Nodes: a Meta-Analysis of Diagnostic Accuracy Studies

Objective: To evaluate the diagnostic accuracy of contrast-enhanced ultrasonography (CEUS) in differentiatingbetween benign and malignant enlarged lymph nodes using meta-analysis. Materials and
Methods: Pubmed,Embase, SCI and Cochrane databases were searched for studies (up to September 1, 2014) reporting the diagnosticperformance of CEUS in discriminating between benign and malignant lymph nodes. Inclusion criteria were:prospective study; histopathology as the reference standard; and sufficient data to construct 2×2 contingencytables. Methodological quality was assessed using Quality Assessment of Diagnostic Accuracy Studies-2(QUADAS-2). Patient clinical characteristics, sensitivity and specificity were extracted. The summary receiveroperating characteristic curve was used to examine the accuracy of CEUS. A meta-analysis was performedto evaluate the clinical utility in identification of benign and malignant lymph nodes. Sensitivity analysis wasperformed after omitting outliers identified in a bivariate boxplot and publication bias was assessed with Eggertesting.
Results: The pooled sensitivity, specificity and AUROC were 0.92 (95%CI, 0.85-0.96), 0.91 (95%CI,0.82-0.95) and 0.97 (95%CI, 0.95-0.98), respectively. After omitting 3 outlier studies, heterogeneity decreased.Sensitivity analysis demonstrated no disproportionate influences of individual studies. Publication bias wasnot significant.
Conclusions: CEUS is a promising diagnostic modality in differentiating between benign andmalignant lymph nodes and can potentially reduce unnecessary fine-needle aspiration biopsies of benign nodes.