Hyperpolarized Magnetic Resonance Imaging in Asthma Pre- and Post-Bronchial Thermoplasty
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|ClinicalTrials.gov Identifier: NCT02263794|
Recruitment Status : Enrolling by invitation
First Posted : October 13, 2014
Last Update Posted : October 1, 2019
|Condition or disease||Intervention/treatment||Phase|
|Asthma||Procedure: Conventional Bronchial Thermoplasty Procedure: Image Guided Bronchial Thermoplasty||Not Applicable|
This is a one year, single centre randomized controlled trial. Subjects will be identified through the London Asthma Centre located at St. Joseph's Hospital and from Hamilton at St. Joseph's Healthcare, and will be given a letter of information for the study. The study will only recruit subjects with asthma who are undergoing BT as part of their normal clinical care and asthma treatment plan. Those interested will sign the consent form at the clinic.
Bronchial thermoplasty (BT) is a novel FDA approved outpatient asthma treatment procedure which aims to "cure" symptoms by permanently reducing airway smooth muscle mass in the lobar and segmental bronchi. Under local anesthetic, radiofrequency energy is delivered to warm the airway wall to 65 degrees celcius. The effect of this procedure is a reduction in airway smooth muscle mass in the treated airways resulting in a reduced potential for bronchoconstriction.
Fourteen asthma patients will be enrolled in the study and each subject will visit the centre on five occasions (three pre-treatment visits and two post-treatment visits). We will evaluate pre-therapy optimization using inflammometry, pre-therapy ventilation defect reproducibility and BT treatment effects (pre-treatment visit 1= 5±2 days pre-optimization, pre-treatment visit 2 = 15±7 days pre-BT, pre-treatment visit 3 = 5±2 days pre-BT, post-treatment visit 4=6 weeks post-BT, post treatment visit 5 = 6 months post-BT). At pre-treatment visit 1, patients will be randomized to image-guided or conventional therapy. For all subjects, at all visits, spirometry, plethysmography and 3He and/or 129Xe MRI will be performed. Methacholine challenge (MCh) will be performed (for those subjects with FEV1 >60%) at pre-treatment visit 3 and post-treatment visit 4 with spirometry and MRI performed pre- and post-MCh. Pre-treatment visit 3 will include a low-dose thoracic CT that will be used to generate a detailed 3D model of the airway tree. MRI will be co-registered to the CT with 3D airway rendering to enable spatial comparisons between ventilation defects and airways.
All subjects will also complete bi-weekly and weekly quality of life questionnaires. Self-reported data will be uploaded by each subject monthly to our website using a confidential and password protected upload.
MRI of the lungs will be performed using an inhaled contrast agent: either Hyperpolarized Helium-3 or Hyperpolarized Xenon-129. Participants will inhale the hyperpolarized gas and perform a breathhold for up to 16 seconds. Two different types of images will be acquired in the coronal plain during each visit: 1) 1H thoracic cavity, and 2) 3He and/or 129Xe static ventilation. Respiration and oxygen saturation will be monitored throughout the imaging session.
|Study Type :||Interventional (Clinical Trial)|
|Estimated Enrollment :||14 participants|
|Intervention Model:||Parallel Assignment|
|Masking:||Single (Outcomes Assessor)|
|Official Title:||Hyperpolarized Magnetic Resonance Imaging in Asthma Pre- and Post-Bronchial Thermoplasty|
|Actual Study Start Date :||October 2014|
|Estimated Primary Completion Date :||December 2022|
|Estimated Study Completion Date :||December 2022|
Experimental: Image guided bronchial thermoplasty
At pre-treatment Visit 3, imaging data will be acquired to generate a patient-specific bronchial thermoplasty treatment plan which will include 15-20 target airways, prioritized in order of importance and grouped by lobe, to be targeted during a single session BT treatment procedure. Airways demonstrating dynamic or static bronchoconstriction will be targeted for BT treatment based on their spacial proximity to ventilation defects.
Procedure: Image Guided Bronchial Thermoplasty
Patient-specific bronchial thermoplasty based on imaging data will be performed during one bronchoscopy session.
Active Comparator: Conventional bronchial thermoplasty
Patients in this group will undergo conventional 3 stage bronchial thermoplasty (during 3 separate bronchoscopies).
Procedure: Conventional Bronchial Thermoplasty
Conventional bronchial thermoplasty is performed during three bronchoscopy sessions each separated by approximately three weeks.
- Whole lung and lobe specific ventilation defect percent (VDP) as measured by 3He or 129Xe [ Time Frame: 48 +/- 2 weeks post bronchial thermoplasty treatment ]Change in VDP post BT
- Pulmonary function measurements [ Time Frame: 48 +/- 2 weeks post bronchial thermoplasty ]Change in pulmonary function post BT
- Quality of Life questionnaires [ Time Frame: 48 +/- 2 weeks post bronchial thermoplasty ]Change in subject reported QOL post BT
- Dyspnea Scales [ Time Frame: 48 +/- 2 weeks post bronchial thermoplasty ]Dyspnea scale score post BT
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02263794
|Hamilton, Ontario, Canada, L8S 4L8|
|Robarts Research Insitute; The University of Western Ontario; London Health Sciences Centre|
|London, Ontario, Canada, N6A 5B7|
|Principal Investigator:||Grace E Parraga, PhD||Robarts Research Institute, The University of Western Ontario|
|Principal Investigator:||David G McCormack, MD||London Health Sciences Centre|