RecruitingPhase 2Radiation therapyEnhanced Local Intensified Radiation Therapy in Elderly Glioblastoma: A Phase 2 Hybrid Randomized TrialGlioblastoma (GBM) is an aggressive malignancy of the central nervous system. Older adults with GBM have a unique constellation of medical, psychosocial, and supportive care needs. To address these challenges, prior work has evaluated the feasibility of hypofractionation, a treatment approach delivering fewer, larger radiation dosages over a shorter time period. Common hypofractionated regimens deliver a lower biologically equivalent radiation dose than the conventional regimens used for younger adults. Whether dose escalated hypofractionation can further improve outcomes in older adults remains unclear. This will be a hybrid randomized control trial comparing the efficacy and safety of dose-escalated and standard hypofractionated radiotherapy among older adults with newly-diagnosed glioblastoma compared to standard three-week course. This research study involves the administration of radiation therapy. Radiation will either be delivered at the standard daily dose or at an increased daily dose over a three weeks course of radiation treatment. Research study procedures will include a screening evaluation to assess eligibility, as well as clinical visits for radiation delivery and to assess symptoms during treatment and at scheduled follow-up times. Participants will be randomly assigned to one of the two arms of the trial: 1. Standard hypofractionated radiation over 3 weeks 2. Dose-escalated hypofractionated radiation over 3 weeks