Contrast-enhanced EUS for differential diagnosis of pancreatic mass lesions: a meta-analysis

Background: Distinguishing pancreatic adenocarcinomas from other pancreatic masses remains challenging with current imaging techniques. Contrast-enhanced EUS further improved the efficacy of EUS to characterize pancreatic lesions. Objective: To assess the accuracy of contrast-enhanced EUS for diagnosing adenocarcinoma in patients with pancreatic masses by pooling data of existing trials. Design: We systematically searched the Medline, PubMed, Web of Science, Embase, and Cochrane Central Trials databases for relevant studies published. Meta-analysis was performed. Pooling was conducted in a fixed-effect model or a random-effects model. Patients: Twelve studies involving 1139 patients were included. Intervention: Contrast-enhanced EUS. Main Outcome Measurements: Meta-analysis and meta-regression analysis. Results: The pooled sensitivity of contrast-enhanced EUS for the differential diagnosis of pancreatic adenocarcinomas was 94% (95% CI, 0.91-0.95), and the specificity was 89% (95% CI, 0.85-0.92). The area under the curve under summary receiver operating characteristic was 0.9732. The pooled positive likelihood ratio was 8.09 (95% CI, 4.47-14.64), and the negative likelihood ratio was 0.08 (95% CI, 0.06-0.10). The subgroup analysis by exclusion of the outliers provided a sensitivity of 93% (95% CI, 0.91-0.95) and a specificity of 93% (95% CI, 0.89-0.95) for the differential diagnosis of pancreatic adenocarcinomas. The area under the curve under summary receiver operating characteristic was 0.9745. Limitations: A small number of studies met the inclusion criteria. Conclusion: Contrast-enhanced EUS is a promising, reliable modality for the differential diagnosis of pancreatic adenocarcinoma in patients with pancreatic mass lesions. The finding of a hypoenhanced lesion was a sensitive and accurate predictor of pancreatic adenocarcinomas. It seems to be a useful tool in clinical practice. (Gastrointest Endosc 2012;76:301-9.)