Inhale and Exhale Breath Holds to Improve the Radiation Therapy Accuracy in People With Upper Abdominal Cancers (INEX-RT P)
May 26, 2026 updated by: University Health Network, Toronto
Inhale and Exhale Breath Holds to Improve the Therapeutic Ratio in Upper Abdominal Cancers Treated With SBRT
This is a prospective quality improvement study.
The INEX RT P study will prospectively evaluate INEX RT R that optimizes radiation dose delivery to the target while minimizing dose to critical organs at risk (OAR) by treating patients with different phases of breath hold (inhale and exhale) during the same course of SBRT.
15 patients with abdominal cancer whom are expected to achieve a dosimetric advantage from this technique due to OAR proximity to target will be treated using INEX RT.
Investigators hypothesize increasing the dose to the RT target by at least 10% while simultaneously decreasing or maintaining dose to adjacent critical OARs when using a combination of breath hold positions to purposefully vary the position of OARs during different fractions of the same treatment course, when compared to RT treatments planned on a single breath hold phase alone (present standard of care).
Study Overview
Status
Recruiting
Conditions
Intervention / Treatment
Study Type
Interventional
Enrollment (Estimated)
15
Phase
- Not Applicable
Contacts and Locations
This section provides the contact details for those conducting the study, and information on where this study is being conducted.
Study Contact
- Name: Laura Dawson, MD FRCPSC FASTRO FCAHS
- Phone Number: 3276 416-946-4501
- Email: Laura.Dawson@uhn.ca
Study Locations
-
-
Ontario
-
Toronto, Ontario, Canada, M5G 2M9
- Recruiting
- Princess Margaret Cancer Centre Toronto, Ontario
-
Principal Investigator:
- Laura Dawson
-
-
Participation Criteria
Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.
Eligibility Criteria
Ages Eligible for Study
- Adult
- Older Adult
Accepts Healthy Volunteers
No
Description
Inclusion Criteria:
- Age ≥ 18
- Any patient undergoing radiation therapy for a cancer lesion in the abdomen in close proximity to OARs that is hypothesized to have differential displacement on inhale and exhale breath hold CT scans of the OAR relative to the tumor.
- Patients need at least 3 fractions of RT
- Critical OARs are within 2 cm of luminal GI structures, chest wall, or previous radiation fields
- Able to receive and understand verbal and written information regarding study and able to give written informed consent
Exclusion Criteria:
- Inability to perform inhale or exhale breath holds during standard workflow CT simulation evaluation
Study Plan
This section provides details of the study plan, including how the study is designed and what the study is measuring.
How is the study designed?
Design Details
- Primary Purpose: Treatment
- Allocation: N/A
- Interventional Model: Single Group Assignment
- Masking: None (Open Label)
Arms and Interventions
Participant Group / Arm |
Intervention / Treatment |
|---|---|
|
Experimental: Imaging
|
Obtain inhale and exhale breath hold images planned to split radiation delivery between inhale and exhale breath hold phases. For radiotherapy courses with an odd number of fractions, the phase of breath hold with higher reproducibility or anatomic advantage will be used for the additional fraction of radiotherapy. If during the treatment planning the investigators determine that the patients will benefit from the multiple breath holds technique, the patients will be treated using the composite breath hold plan. Additional one or two cone beam CTs will be obtained on treatment days for all patients using the inhale and exhale breath hold technique. |
What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
Total dose to radiation targets and OARs
Time Frame: 12 Months
|
Total dose to radiation targets and OARs on standard workflow (FB ITV or exhale/inhale single breath hold phase only) compared to INEX RT.
Unit: Gy
|
12 Months
|
Secondary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
Positional change between a deep inhale and deep exhale breath hold
Time Frame: 12 Months
|
Evaluate the motion of critical OARs during inhale and exhale breath holding techniques during simulation and during daily treatments, including the magnitude of positional change between a deep inhale and deep exhale breath hold.
Unit: mm
|
12 Months
|
Collaborators and Investigators
This is where you will find people and organizations involved with this study.
Study record dates
These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.
Study Major Dates
Study Start (Actual)
May 25, 2026
Primary Completion (Estimated)
May 30, 2027
Study Completion (Estimated)
January 30, 2028
Study Registration Dates
First Submitted
May 13, 2026
First Submitted That Met QC Criteria
May 13, 2026
First Posted (Actual)
May 19, 2026
Study Record Updates
Last Update Posted (Actual)
May 29, 2026
Last Update Submitted That Met QC Criteria
May 26, 2026
Last Verified
May 1, 2026
More Information
Terms related to this study
Keywords
Other Study ID Numbers
- 26-5095
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
No
Studies a U.S. FDA-regulated device product
No
This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.