Evaluation of Endoscopic Ultrasound Shear Wave Elastography (EUS-SWE) for the Diagnosis of Pancreatic Adenocarcinoma.

Pancreatic adenocarcinoma (PA) is the most common tumor of the pancreas, representing more than 90% of all solid pancreatic neoplasia and 55% -73% of solid pancreatic masses. Given its poor prognosis and the major therapeutic consequences, the discrimination between PA and other pancreatic solid lesions is mandatory. Endoscopic ultrasound (EUS) is admitted as the most sensitive imaging procedure for the detection and characterization of pancreatic tumors. Based on only endosonographic features, it remains difficult to differentiate PA from other solid masses, the specificity (Spe) and accuracy of EUS for the diagnosis of pancreatic tumor malignancy range from 53-69% and 72-83%, respectively. Over the last 15 years, endoscopic ultrasound fine needle aspiration (EUS-FNA) or more recently fine needle biopsy (EUS-FNB) has demonstrated its efficiency for tissue sampling and pathologic diagnosis of PA. Complementary techniques have been developed to increase the diagnostic performance of EUS. EUS-Elastography (EUS-E) is another EUS image enhancement technique, which rational based on the difference in elasticity between the tissues. There are two types of elastographies: strain elastography (SE) and shear wave elastography (SWE). Several studies have demonstrated the utility of ultrasound SWE (US-SWE) for the differential diagnosis of lesions of the breast, thyroid, prostate and for detection of pancreatic fibrosis and chronic pancreatitis. However, to date, there is no data about the performance of EUS-SWE for the differential diagnosis of pancreatic solid lesions.