Baseline total brain volume predicts changes in quality of life and overall survival after cranial radiotherapy in older patients with glioblastoma: Results from the prospective BRITER study.

Background: Short-course partial brain radiotherapy ± chemotherapy for older patients with GBM extends survival but there is no validated evidence for prediction of individual risk of acute radiotherapy-related side effects.

Methods: This prospective multicentre observational trial recruited patients with newly diagnosed GBM aged ≥65 planned for cranial radiotherapy. Baseline MRI scans were analyzed for markers of brain resilience including relative total brain volume (ratio of cerebrospinal fluid (CSF) volume to total intracranial volume (TIV)) and their relationship to change in quality of life (QoL).