This is a phase 1 study to examine the safety and tolerability of biology-guided dose intensified hypofractionated radiation therapy (RT) using MR-Linac for patients with high grade glioma (HGG). Investigators will enroll 20 patients with Grade 3 or 4, IDH wild-type (IDHwt), HGG. Intraoperative assessment of residual tumor burden will be performed at 6 surgical margins (anterior, posterior, superior, inferior, medial, lateral) using FastGlioma. Each margin will be graded on a scale of 0 to 3, with 0 being no tumor, 1 atypical cell, 2 sparse tumor infiltration, and 3 dense tumor infiltration.