BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) still has a dismal 5-year overall survival of 13 %. Chemotherapy is increasingly used as treatment in both (neo-) adjuvant and palliative conditions. However, the overall survival benefits of chemotherapy must be weighed against significant side effects leading to a reduction in quality of life. CE-EUS and elastography could provide additional information about the vascularization and elasticity of the pancreatic tumor. The aim of this study was to investigate if contrast-enhanced endoscopic ultrasound and/or elastography could be suitable to predict the effectiveness of FOLFIRINOX. METHODS: Single center, prospective proof-of-concept study in which intravenous contrast agent was administered and strain ratio was calculated in patients undergoing EUS in their regular diagnostic work-up. Directly after contrast administration, a video of 120 s was recorded and afterwards tracked and fitted by a Modified Local Density Random Walk (mLDRW) model. RESULTS: We included 17 patients. Based on cross-sectional imaging based RECIST criteria, chemotherapy treatment was effective in 11 patients and not effective in 6 patients. The contrast dispersion parameter (κ1) differed significantly between both groups in favor of the responders: 2.994 (IQR 1.670-5.170) vs 1.203 (IQR 0.953-1.756), p = 0.005. The elastography strain ratio was higher in the effectively treated group (20.9 vs 13.6, p = 0.138). CONCLUSION: This proof-of-concept study showed that the dispersion parameter of the first wave of contrast was 2.5 times higher in patients in whom FOLFIRINOX was effective, suggesting that this parameter could possibly be a reliable prediction tool.