Simulation-Free Celiac Plexus Pain Ablation Using Stereotactic Body Radiotherapy in Patients With Cancer-Related Celiac Pain

The feasibility and safety of the simulation-free adaptive radiotherapy workflow for celiac plexus SBRT for clinical use. Feasibility defined as the successful completion of the simulation-free ART workflow through treatment delivery in the first on-table treatment attempt for at least 80% of patients.

All of the following criteria must be met to be deemed feasible:

• Meets all priority 1 OAR constraints
• Meets a PTV_Opt_2500 and PTV_Opt_2000 priority 2 constraints
• Patient specific QA pass as per institutional standards
• Patient able to tolerate treatment position for CBCT and entirety of treatment process. If a break is required and the patient is repositioned, the ART process must repeat from CBCT acquisition
• Complete delivery of all planned monitor units

Average time required for each component of the simulation-free ART workflow, including but not limited to plan generation using diagnostic imaging, pre-treatment activities (e.g., on-table patient setup/imaging, dose prediction, segmentation of daily contours, plan optimization and evaluation), and treatment delivery.

Dosimetric comparison of radiation plans created on traditional offline CBCT images with those created using the simulation-free ART workflow (i.e., comparison of target coverage, sparing of organs-at-risk).

Frequency of online re-adaptation within the sim-free workflow. Readaptation defined as the need to regenerate a treatment plan after an initial plan had been generated that does not satisfy treatment parameters.

Overall patient satisfaction with celiac plexus SBRT using a simulation-free, adaptive radiotherapy workflow. This will be assessed using the Radiotherapy Experience Questionnaire (RTEQ) which is a validated RT experience questionnaire that reports patient experiences with the overall treatment process by answering statements on a scale of strongly agree to strongly disagree. Given that this is a novel workflow/process, the results of the questionnaire will shed light on their overall experience.

Change in Brief Pain Inventory pain scale, where on a scale 0 is "No Pain" and 10 is "Pain as bad as you can imagine", recorded in the pain diary at baseline/screening, day of SBRT prior to treatment, and 6 weeks after sim-free celiac plexus SBRT.

Change in the amount of pain medications (Morphine equivalents) recorded in the pain diary at baseline/screening, day of SBRT prior to treatment, and 6 weeks after sim-free celiac plexus SBRT. Patients will record number of medication units taken (unit of medication is a tablet or capsule, a millilitre (mL) of liquid, a suppository, or a patch).

Any CTCAE Grade 3+ Toxicity at 6 weeks related to the SBRT treatment.

The overall cost of simulation free workflow compared to select retrospective cases treated on conventional workflow. Timepoints include simulation, planning, treatment, and follow up. Components include planning, therapist, clinician.

Mean difference in location between diagnostic, planning, and hypersight scans at each time point for select organs at risk. These include liver, stomach, duodenum, pancreas, kidneys, small bowel, aorta, and large bowel. Rigid registration to spinal column as baseline (or aorta). Metrics will include center of mass (COM).

Mean difference in location between diagnostic, planning, and hypersight scans at each time point for select organs at risk. These include liver, stomach, duodenum, pancreas, kidneys, small bowel, aorta, and large bowel. Rigid registration to spinal column as baseline (or aorta). Metrics will include distance to agreement (DTA).

Mean difference in location between diagnostic, planning, and hypersight scans at each time point for select organs at risk. These include liver, stomach, duodenum, pancreas, kidneys, small bowel, aorta, and large bowel. Rigid registration to spinal column as baseline (or aorta). Metrics will include average symmetric surface distance (ASSD).

Mean difference in location between diagnostic, planning, and hypersight scans at each time point for select organs at risk. These include liver, stomach, duodenum, pancreas, kidneys, small bowel, aorta, and large bowel. Rigid registration to spinal column as baseline (or aorta). Metrics will include dice for volume overlap (DSC).

Mean difference in location between diagnostic, planning, and hypersight scans at each time point for select organs at risk. These include liver, stomach, duodenum, pancreas, kidneys, small bowel, aorta, and large bowel. Rigid registration to spinal column as baseline (or aorta). Metrics will include deformation vector field (DVF).