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

A Prospective Pilot Clinical Trial of Simulation-Free Celiac Plexus Pain Ablation Using Stereotactic Body Radiotherapy in Patients With Cancer-Related Celiac Pain

This is a prospective, single-arm, pilot feasibility clinical trial designed to evaluate the feasibility and safety of a simulation-free adaptive radiotherapy workflow to enable single-session celiac plexus SBRT planning and delivery. In this trial, the treatment itself is non-investigational (standard-of-care celiac plexus SBRT) but the treatment workflow (simulation-free, using adaptive radiotherapy to compress treatment planning and delivery into a single session) is novel. Investigators hypothesize 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.

Study Overview

• Status: Not yet recruiting
• Conditions: Pancreatic Cancer; Advanced Cancer
• Intervention / Treatment: Other: Treatment plan

Detailed Description

A standard treatment for pain caused by cancer affecting the celiac plexus (a group of nerves in the upper abdomen behind the stomach and pancreas) is a type of radiation therapy called stereotactic body radiotherapy (SBRT). In the usual process for this type of radiation treatment, the patient would first have a special radiation planning scan called a computer tomography simulation (CTsim) to create a personalized treatment plan. The planning process usually takes 5 to 10 days, which means treatment may begin up to 2 weeks after the initial CTsim scan. Recent technology has allowed for treatment to be planned without a separate CTsim scan, called a CTsim-free workflow. In this study, investigators will use pre-existing scans (such as diagnostic imaging) to create the patient's treatment plan. On the day of treatment, the care team will use a technique called Adaptive Radiotherapy (ART) to adjust the plan based on the patient body's position and anatomy that day, allowing planning and treatment to happen in a single visit.

• Study Type: Interventional
• Enrollment (Estimated): 5
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Michael Yan; Phone Number: (416) 946-2320; Email: michael.yan@uhn.ca

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M5G 2M9
      • Princess Margaret Cancer Centre
      • Principal Investigator: Michael Yan

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Subjects must have histologically or cytologically confirmed cancer that is metastatic or unresectable, and considered appropriate per the treating physician to receive celiac plexus SBRT.
• Age >18 years. Because no data are currently available on the use of celiac axis SBRT in subjects ≤18 years of age, children are excluded from this study.
• Performance status: ECOG Performance status ≤ 3
• Severe retroperitoneal pain syndrome (radiates from the lower back to the upper abdomen, belt- like distribution), intensity of at least 5 on 11-point Brief Pain Inventory (BPI, average pain) scale.
• Subjects must have anatomical involvement of the celiac plexus on the diagnostic CT, PET/CT, or MRI. This includes: Any pancreatic cancer, any other cancer that on imaging demonstrates either gross involvement of the celiac blood vessels or celiac plexus on imaging OR haziness around the celiac blood vessels that typically implies tumor engulfment.
• Prior chemotherapy or biological treatment is allowed, but any active oncological treatment should be stopped at least 1 week prior to radiation therapy and renewed at least 1 week following radiation therapy.
• Subjects must have the ability to understand and the willingness to sign a written informed consent document.
• Subjects must have a diagnostic CT of the abdomen and pelvis, with or without contrast, acquired < 28 days prior to the study consent.

Exclusion Criteria:

• In ability to tolerate lying supine and still for at least 45 minutes.
• Performance status: ECOG Performance status of 4.
• Previous radiotherapy to the upper abdomen overlapping with the projected site of treatment.
• Pregnant or breastfeeding women are excluded from this study.
• Subjects with conditions associated with increased risk of side effects from radiation such as inflammatory bowel disease and scleroderma.
• Women of childbearing potential must have a negative pregnancy test within 14 days of study entry. If pregnancy test is not clinically indicated as determined by treating physician or protocol principal investigator, documentation of this exception is sufficient in lieu of a pregnancy test.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Sim-free ART workflow

Other: Treatment plan; Simulation-free radiation treatment planning, in which pre-existing diagnostic images are used to generate a radiation treatment pre-plan (as opposed to acquiring planning-specific image sets). This will be paired with the use of online adaptive radiotherapy (ART) to refine the pre-plan to create a final plan that matches the on-table internal target and gastrointestinal anatomy observed with on-board imaging on the day of treatment. This enables single-session celiac plexus SBRT planning and delivery.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Successful treatment plan workflow of 80% of patients	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	1 year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Component time	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.	1 year
Dosimetric comparison of radiation plans	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).	1 year
Frequency of online re-adaptation	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.	1 Year
Patient satisfaction	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.	1 year
Change in the Brief Pain Inventory pain scale	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, 6 weeks after sim-free celiac plexus SBRT.	6 Weeks
Change in Amount of Pain Medication	Change in the amount of pain medications (Morphine equivalents) use 6 weeks after sim-free celiac plexus SBRT, recorded in the pain diary. 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).	6 weeks
TCAE Grade 3+ Toxicity	Any CTCAE Grade 3+ Toxicity at 6 weeks related to the SBRT treatment.	6 weeks
Cost of workflow	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.	1 year
Mean difference between diagnostic and ETHOS plans (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 center of mass (COM).	1 year
Mean difference between diagnostic and ETHOS plans (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 distance to agreement (DTA).	1 year
Mean difference between diagnostic and ETHOS plans (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 average symmetric surface distance (ASSD).	1 year
Mean difference between diagnostic and ETHOS plans (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 dice for volume overlap (DSC).	1 Year
Mean difference between diagnostic and ETHOS plans (DVF)	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).	1 Year

Collaborators and Investigators

• Sponsor: University Health Network, Toronto

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): June 1, 2027
• Study Completion (Estimated): June 1, 2027

Study Registration Dates

• First Submitted: May 26, 2026
• First Submitted That Met QC Criteria: June 3, 2026
• First Posted (Actual): June 9, 2026

Study Record Updates

• Last Update Posted (Actual): June 9, 2026
• Last Update Submitted That Met QC Criteria: June 3, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Pancreatic Cancer; SBRT; Celiac
• Additional Relevant MeSH Terms: Endocrine System Diseases; Neoplasms by Site; Neoplasms; Metabolic Diseases; Intestinal Diseases; Digestive System Neoplasms; Digestive System Diseases; Gastrointestinal Diseases; Endocrine Gland Neoplasms; Pancreatic Diseases; Malabsorption Syndromes; Nutritional and Metabolic Diseases; Pancreatic Neoplasms; Celiac Disease
• Other Study ID Numbers: 25-5377

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No