Simulation-Free Celiac Plexus Pain Ablation Using Stereotactic Body Radiotherapy (SBRT) in Participants With Cancer-Related Celiac Pain

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.

Celiac plexus nerve pain, a type of abdominal pain, is common in people with pancreatic cancer. In fact, 70-80% of these people say they have very bad, or debilitating, pain in the lower part of their abdomen and/or the area behind their abdomen where they were diagnosed with pancreatic cancer (1). Recently, a type of treatment called celiac plexus radioablation, which is done using a type of radiation called stereotactic body radiotherapy (SBRT), has been recognized as a new standard-of-care therapy option for these people (2-4). However, celiac plexus radioablation takes a long time to plan and deliver when compared to traditional treatment approaches, which don't require so much time and so many visits (5). A better workflow is needed to make treatment planning and delivery happen faster. This better workflow should make things easier on people who are experiencing this severe pain and help them start treatment faster to feel better sooner. One way to create this better workflow for celiac plexus radioablation is to use single-fraction SBRT and to use simulation-free radiation treatment planning. For this type of workflow, pre-existing diagnostic images are used to make the treatment plan, rather than making people get new images before they can start getting treated for their pain (6). This workflow uses an online tool called online adaptive radiotherapy (ART) to help create and adjust the treatment plan based on what can be seen inside the body on the pre-existing diagnostic images so that it targets the right spot. The research study team has developed an institutional celiac plexus auto-planning template using a commercial CT-guided ART platform. The team has looked back at past cases and confirmed that this workflow can safely create treatment plans in a short amount of time. The adaptive radiotherapy that is used in this simulation-free workflow is a a standard-of-care practice for other disease sites. There have been previous research studies that show that it works to lessen the time to treatment when treating other areas of the body (7-9). The novel approach in this study is the workflow, and as such, the purpose of this study is to demonstrate the feasibility and safety of a simulation-free workflow for celiac plexus SBRT using online adaptive radiotherapy.