Radiotherapy - Cerebrovascular Reactivity (RT-CVR Study)

Study Overview
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Brief Summary
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Brain tumours often have low oxygen levels, and that makes them more resistant to radiation therapy. If patients breathe the right mixture of oxygen during treatment, radiation may work better. In this study, patients with brain tumour will undergo a special MRI test while they breathe different mixtures of oxygen and carbon dioxide to find out whether oxygen levels improve in the tumor. Patients will also be asked to repeat this MRI test during the second week of radiation therapy, as well as 3 months, 6 months and 1 year after RT. The MRI test after RT will help us understand how the blood vessels in the normal brain are affected by radiation.

Official Title
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MRI Changes With Administered Oxygen and Carbon Dioxide in Patients With Brain Tumors Receiving Radiotherapy: A Pilot Study

Conditions
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Brain Neoplasms

Intervention / Treatment
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* Procedure: MRI


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with primary gliomas visible on MRI who are planning to receive radiotherapy or Patients with brain metastases>1cm who are planning to receive radiotherapy Karnofsky Performance Status >60 Age 18 years Patients must be willing to visit Toronto Western Hospital for at least one MRI scan prior radiotherapy Exclusion Criteria: Seizures not controlled with medications, or non compliance with prescribed anti-seizure medication Prior radiation therapy to the brain Pregnancy Unwilling or unable to co-operate with breathing maneuvers Respiratory or cardiac limitations to breathing at 20 L/min Medical contra-indications to limited hypercapnia or hypocapnia (known increased intracerebral pressure, metabolic acidosis or alkalosis) Contraindication to MRI (patients weighing>136 kgs-weight limit for the scanner tables; allergy to MR contrast agent; patients with pacemakers, cerebral aneurysm clips, shrapnel injury or implantable electronic devices not compatible with MRI) Other medical conditions deemed by the PI or associates to make the patients ineligible for protocol procedures

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: MRI for brain mets<br> | Procedure: MRI<br>* Patients will be scanned while breathing in varying amounts of oxygen and carbon dioxide in varying amounts through a breathing device.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| - To measure the inter-patient variability of change in tumour oxygenation with carbogen adminstration using MRI |  | 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| - To determine whether modulation of oxygen and carbon dioxide administration can improve tumour oxygenation relative to standard carbogen breathing on MRI |  | 2 years | 
| - To determine whether changes in tumour oxygenation with carbogen administration are different during the second week of radiotherapy compared to baseline measurements |  | 2 years | 
| - To determine whether the normal brain cerebrovascular reactivity (CVR) measured with MRI changes through a course of radiotherapy and follow-up |  | 2 years | 
| - To determine whether CVR differs between radiation exposed and non-exposed normal brain tissue in a given patient after radiotherapy |  | 2 years |