The purpose of this study is to determine whether magnetic resonance imaging (MRI) using inhaled hyper polarized xenon-129 (129Xe) gas, and conventional contrast can help visualize impaired lung function and detect changes over time in patients receiving treatment as well as those who don't. 129Xe is a special type of xenon gas and when inhaled during MRI may be able to show areas of abnormal thickening of parts of the lungs. These images combined with images taken with injected contrast agents or other special types of MRI such as conventional proton (1H) MRI may provide a better way to look at lung structure and function. The ultimate goal is to predict the degree of radiation-induced lung injury that will develop in a given patient for a given treatment plan. The investigators anticipate that these images will provide more specific information about lung disease than standard lung function tests. The use of 129Xe MRI is investigational. Investigational means that these tests have not yet been approved by the US Food and Drug Administration and are only available in research studies like this one. In addition, standard MRI with contrast is not typically done as standard of care for monitoring changes due to thoracic radiation therapy, therefore, its use in this study is also considered investigational. Healthy volunteers are being asked to participate in this study because to develop a database of functional images that are representative of healthy lungs.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
DIAGNOSTIC
Masking
NONE
Enrollment
25
Hyperpolarized xenon will be administered in multiple doses in volumes up to 25% of subject total lung capacity (TLC) followed by a breath hold of up to 15 seconds. Subsequent 129Xe doses will only be administered once the subject is ready to proceed.
Conventional 1H MRI will be used to provide anatomical reference scans, as well as pulmonary perfusion.
Duke University Medical Center
Durham, North Carolina, United States
Change in Pulmonary Function, as Measured by Ventilation Defect Percentage (VDP)
"Ventilation" is defined as the regional 129Xe airspace signal divided by the top 1% of 129Xe airspace signal (representing open-airway ventilation). A "Ventilation Defect" is defined as any region of lung where the Ventilation signal is more than 2 standard deviations below the mean Ventilation signal of healthy volunteer subjects' lungs. "Ventilation Defect Percentage", or VDP, is defined as the volume of a subject's Ventilation Defects divided by the volume of the subject's lung, multiplied by 100%.
Time frame: Baseline, following radiation treatment (up to 3 months)
Change in Gas Exchange Defect Percentage (EDP) Following RT (Radiation Treatment)
"Gas exchange" is defined as the ratio of the signal from 129Xe transiently bonding with hemoglobin in the pulmonary capillaries to the local 129Xe airspace signal. In other publications, the investigators have referred to this as "RBC (red blood cell) transfer". A "Gas Exchange Defect" is defined as any region of lung where the Gas Exchange signal is more than 2 standard deviations below the mean Gas Exchange signal of healthy volunteer subjects' lungs. "Gas Exchange Defect Percentage", or EDP, is defined as the volume of a subject's Gas Exchange Defects divided by the volume of the subject's lung, multiplied by 100%.
Time frame: Baseline, following RT (up to 3 months)
RBC (Red Blood Cell) to Barrier Ratio Following RT
"RBC:barrier ratio" is defined as the ratio of the whole lung signal from 129Xe transiently bonding with hemoglobin in the pulmonary capillaries to the whole lung signal from 129Xe in the alveolar barrier tissue.
Time frame: Baseline, following RT (up to 3 months)
Change in High Barrier Uptake Percentage (HBUP) Following RT
"Barrier Uptake" is defined as the ratio of the regional signal from 129Xe dissolved in the interstitial space within the alveolar walls to the regional signal from 129Xe in the adjacent airspaces. "High Barrier Uptake" is defined as any region of lung where the Barrier Uptake signal is more than 2 standard deviations above the mean Barrier Uptake signal of healthy volunteer subjects' lungs. "High Barrier Uptake Percentage", or HBUP, is defined as the volume of a subject's lung exhibiting High Barrier Uptake divided by the total volume of the subject's lung, multiplied by 100%.
Time frame: Baseline, following RT (up to 3 months)
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