Diagnostic performance of endoscopic ultrasound elastography for differential diagnosis of solid pancreatic lesions: A propensity score-matched analysis.

Background: Endoscopic ultrasound-elastography (EUS-EG) is a non-invasive complementary diagnostic method for differential diagnosis of solid pancreatic lesions (SPL). However, the optimal strain ratio (SR) value and diagnostic performance of EUS-EG have not yet been determined in pancreatic neuroendocrine neoplasm (PNEN), mass-forming pancreatitis (MFP), and pancreatic ductal adenocarcinoma (PDAC). We aimed to determine the optimal SR value in EUS-EG for differential diagnosis of SPLs.

Methods: Patients who underwent EUS-EG for SPL evaluation between July 2016 and June 2019 were retrospectively investigated. Patients were divided into three groups based on the final diagnosis (PNEN, MFP, or PDAC). Patient demographics, characteristics of SPL, and EUS-EG were compared.

Results: The mean (± standard deviation) SR value for each group were 11.85 ± 7.56 (PNEN, n = 10), 11.45 ± 5.97 (MFP, n = 37), and 22.50 ± 13.19 (PDAC, n = 87). Multinomial logistic regression analysis revealed that an increase of SR value was significantly associated with PDAC (PNEN versus PDAC, p = 0.0216; MFP versus PDAC, p = 0.0006). The optimal cut-off value for differential diagnosis was confirmed as 17.14 after propensity score matching.

Conclusions: We provided the optimal cut-off SR values for differential diagnosis between MFP and PDAC. EUS-EG can be used as a supplementary diagnostic method in the diagnosis of SPLs. (Clinical trial registration number: https://cris.nih.go.kr/cris: KCT0002082).