The primary objective is to study the feasibility and efficacy of individually optimized CE 4D-CT for PDA in radiotherapy simulation.

Compared with current clinical practice, the individually optimized CE 4D-CT can potentially provide much improved tumor-to-parenchyma conspicuity of pancreatic adenocarcinoma. This will help the radiation oncologists or radiologists to contour the tumor with higher precision and confidence, and compute the tumor volume and tumor motion more accurately.

Inclusion Criteria:

1. Patients 18 years old or older
2. Patients with PDA who have not had surgical removal of their tumor and who are planned for treatment with radiotherapy in the Radiation Oncology Department at the University of Maryland.
3. Patients who have signed the contrast consent form and have been recommended by physicians to have contrast-enhanced CT scans.
4. Patients who have signed the consent form for this study

Exclusion Criteria:

1. Pregnant or breast-feeding women.
2. Patients with severely decreased renal function19-21.
3. Patients with known severe allergic reactions to contrast.
4. Patients who have difficulty lying flat on their back for extended periods of time.
5. Patients with breaths per minute (BPM) rate less than 10, due to the limitation of 4D-CT image reconstruction software.

GI/GU multi-d clinic

1 year