Retroperitoneal Pain Syndrome

Participants who are experiencing abdominal pain due to having cancer in their pancreas may be eligible for this research study. For this type of pain, doctors often recommend radiation therapy to help with the pain. This radiation therapy is called stereotactic body radiotherapy (SBRT). Preparing for SBRT typically takes a week or longer. In this research study, doctors want to test a new workflow in order to shorten the time it takes for participants to receive SBRT to help with their pain. Doctors typically determine how to administer the SBRT by doing a simulation, which requires a CT (Computerized Tomography) scan. The CT scan is used to create a treatment plan. It can take time to schedule this CT scan and then it takes 5-10 days to create a treatment plan. A way to reduce the planning time for SBRT is to use the CT scan that participants had when their cancer was diagnosed to plan the SBRT. This new workflow can cut down the time it takes to schedule another CT scan and plan for and deliver SBRT. The workflow where doctors use a pre-existing CT scan is called CTsim-free treatment planning. CTsim-free treatment planning is what is being tested in this research study.