Contrast-Enhanced Ultrasound for differential diagnosis of pancreatic mass lesions: a meta-analysis

Aim: To evaluate the diagnostic accuracy of contrast-enhanced ultrasound (CEUS) as a method for diagnosing pancreatic lesions with regard to the ductal pancreatic carcinoma and the differentiation of neoplastic from non-neoplastic lesions. Material and methods: Relevant studies published by September 6, 2015 were retrieved from PubMed, Embase, and Cochrane Central Trials databases. The articles included were mainly based on the following criteria: use of CEUS as the diagnostic tool, and the use of histology as the reference method. Two independent reviewers inspected all these papers to confirm the matching of the inclusion criteria. One reviewer with methodological expertise extracted the data from the included studies. Sensitivity, specificity and diagnostic odds ratio (DOR) were used to obtain overall estimates. Results: Eighteen studies out of 734 articles initially identified met the inclusion criteria. The primary study objective with respect to ductal adenocarcinoma was verified in 15 studies. The pooled estimate of CEUS sensitivity for the differential diagnosis of duct adenocarcinomas was 0.90 (95 % CI, 0.89-0.92), and the specificity was 0.88 (0.84-0.90). The pooled estimate for DOR was 56.38 (29.91-106.33). The area under the curve under the summary receiver operating characteristic (SROC) was 0.95. 12 out of 18 studies examined CEUS sensitivity and the average specificity with regard to the secondary study objective, distinguishing between neoplastic lesions and non-neoplastic lesions, were 0.95 (0.94-0.96) and 0.83 (0.77-0.87). The pooled estimate for DOR was 73.25(45.31-118.43). The area under the SROC curve was 0.96. Conclusions: CEUS is a promising, reliable modality for the differential diagnosis of pancreatic adenocarcinoma in patients with pancreatic mass lesions. The presence of a hypoenhanced lesion was a sensitive predictor of pancreatic adenocarcinomas. It seems to be a useful tool in clinical practice.