Using Ventilation and Perfusion MRI at a 0.35 T MR-Linac to Predict Radiation-Induced Pneumonitis in Lung Cancer Patients

Motivation: Early predictors of radiation-induced pneumonitis in patients receiving MR-guided radiotherapy allowing a closer follow up and taking early countermeasures to avoid a severe disease progression have not yet been identified. Goal(s): We aimed at finding functional MR-based biomarkers acquired during treatment that allows the prediction of radiation-induced pneumonitis (RP) for lung cancer patients directly after MR-guided radiotherapy. Approach: For 19 patients, ventilation- and perfusion-maps were acquired using a non-contrast enhanced free-breathing technique and investigated in different regions of the irradiated lung. Results: Changes over treatment in the ventilation around the tumor significantly separate between RP and non-RP group. Impact: The acquisition of additional functional lung imaging during MR-guided radiotherapy requires little effort while offering the opportunity to identify lung cancer patients at risk of developing radiation-induced pneumonitis right after treatment and to take early countermeasures to avoid severe complications.