Drug delivery in solid tumors, whether administered systemically or locoregionally, is hindered by an elevated interstitial fluid pressure (IFP). Stromal targeting therapies are in active development, aiming to enhance drug transport after systemic or locoregional delivery. To date, no clinical methods are available to quantify tumor biophysical properties (including IFP). The investigators aim to use a combination of dynamic contrast enhanced MRI and computational fluid modeling (CFD) to measure stromal IFP in patients with pancreatic cancer and in patients with ovarian or colonic peritoneal carcinomatosis (PC). Computational data will be correlated with therapy response, platinum drug penetration, and invasively measured biophysical parameters after intravenous (pancreas) or intraperitoneal (ovarian/colonic PC) administration of a platinum compound. This would be the first in depth clinical study addressing this important topic, and could pave the way to developing personalized computational based treatment approaches aimed at targeting the biophysical environment of the tumor stroma in order to enhance cancer drug delivery.