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.