Radiation induced lung disease (RILD) can occur following thoracic irradiation, chemotherapy and immunotherapy in lung cancer patients, manifesting as inflammation, radiation pneumonitis or fibrosis. Oxygen Enhanced (OE)-MRI provides spatial information on oxygen delivery to lung tissue. Five non-small cell lung cancer patients underwent OE-MRI pre and post radiotherapy. Statistically significant changes were measured between pre and post radiotherapy scans in both the contralateral and ipsilateral lungs. These findings indicate that OE-MRI can assess changes in lung function following radiotherapy, with potential application for personalised therapy and reduction of toxicity.