HypErpolarised Xenon PuLmonary MRI in the Evaluation for EndobronChial Lung Volume ReductIon Therapy (EXPLICIT)

With 3 million deaths per year, COPD is the third leading cause of deaths worldwide. One treatment to improve symptoms and life expectancy in patients with severe COPD is lung volume reduction (LVR) therapy. In patients with COPD, the lungs or parts of the lung are damaged and over-inflated, reducing their function. This over-inflation may cause compression of less damaged better working parts of the lung, making this good lung less efficient. LVR involves deflating the most damaged parts of the lung, enabling the less damaged but more normal compressed lung to work more efficiently. One-way expiratory endobronchial valves, only allowing air to flow out of the lung have been developed to deflate the damaged lung volume. These are placed in the airway(s)/bronchi leading to the over-inflated lung by bronchoscopy. When the airway supplying the targeted lung is blocked with the valve(s), the air can only flow out and the targeted lung deflates resulting in LVR. For deflation to happen the targeted area of lung should only have air flow coming in from the bronchus supplying it and have no connection with other parts of the lung (“collateral ventilation (CV)”). CV enables air to enter the damaged lung via routes other than the bronchus and this keeps it inflated. The current practice to assess the presence of CV is with CT and a technique called Chartis which measures air flow in the airways at bronchoscopy. When/if CV has been excluded, suitable patients may be offered LVR using valves. Chartis requires bronchoscopy, and currently alongside CT, results in an incorrect decision on the use of valves in approximately 30% of patients. This results in either suitable patients not being treated or patients being selected for treatment who do not benefit. Improvement of the current assessment methods may result in better patient selection and a reduction in bronchoscopies and failed valve insertion, improving patient care and reducing costs. MRI scanning?with a special gas (hyperpolarised xenon) breathed in during the scan could potentially identify suitable patients for treatment. This technique?shows the movement of xenon within the lungs and?moving out of the lungs into the bloodstream, in a similar way to oxygen and has been used safely in thousands of patients around the world, and more than 500 in Oxford. In research studies on COPD patients, hyperpolarised xenon MRI scans has been shown to detect CV. We aim to observe whether these patterns of CV correlate with the success of LVR therapy using endobronchial valves. We will observe the pattern of CV in those who have been selected to undergo valve treatment (Cohort A) and those who have been deemed ineligible for valve treatment (Cohort B). By doing so, we may be able to observe a pattern on hyperpolarised xenon MRI that will help identify those who are more or less likely to benefit from valve treatment. This would improve the patient experience by removing the need for a Chartis bronchoscopy, make valve insertion more likely to be successful and reduce costs to the NHS.