Magnetic Resonance Imaging Biomarkers for Assessment of Radiation-Induced Brain Damage in Adult Patients with Lower Grade Glioma

This PhD thesis investigates how MRI scans can improve the detection and understanding of brain damage in adults treated with radiation for lower-grade brain tumours (gliomas). As more patients are living longer after such treatment, protecting mental abilities like memory and attention is becoming increasingly important. The research compares several MRI techniques, since brain injury from radiation can show up in different ways, including changes in blood vessels, inflammation, and loss of brain volume.

The findings show that a single MRI method is not able to capture the complexity of radiation-induced brain injury and a combination of imaging techniques is needed to form a complete picture of when and where damage occurs or progresses. For example, certain MRI methods show small brain bleeds and decline in white matter health, and these changes are not equally distributed. Furthermore, it seems that brain volume changes occur even in the brain hemisphere opposite the tumour. All these changes occur at different timepoints from radiotherapy and only for some the severity corresponds with the volume of radiotherapy dose. Brain bleeds and volume changes, together with the volume of radiation dose seem to be linked to subtle changes in abilities like memory or information processing, but also not in an equal manner.

The thesis concludes that using multiple MRI strategies together allows for earlier and more accurate detection of damage to better help tailor treatments, so patients could maintain quality of life for longer.