Delineating pancreas and liver tumors is difficult. Fortunately, dual-energy CT has shown to improve the visibility of these tumors allowing for dose escalation and therefore and increase in patient survival. This project’s goal is to investigate the novel Twin Beam dual-energy CT modality and its application in radiation therapy. The specific goals for the project will include quantifying imaging features of pancreas and liver tumors from dual-energy CT data, perform a tumor contouring study using the dual-energy CT data and finally quantifying CTDI as a function of patient size and imaging features.