Temporally-modulated Pulsed Radiation Therapy (TMPRT) After Prior EBRT for Recurrent IDH-mutant Gliomas

Inclusion Criteria: * Histologically confirmed recurrent IDH-mutant gliomas (either astrocytoma or oligodendroglioma) with prior external beam radiation therapy (EBRT) to the same region. The recurrent tumor may be either histologically confirmed or based on clinical assessment. Any number of prior recurrences is allowed. * Maxium tumor diameter of 7 cm or less. * Prior EBRT is ≥ 2 years ago. * The region for reirradiation should have received at least 45 Gy from the prior EBRT but no more than 75 Gy. The prior EBRT could be either photon-based or proton-based. * Prior SRS to the same region is permitted as long as the cumulative dose of EBRT plus SRS is no more than 75 Gy. The prior SRS should be completed at least 6 months ago. * Life expectancy ≥ 12 months * At least 18 years of age. * Karnofsky performance status (KPS) of at least 70%. * Females of childbearing potential (defined as a female who is non-menopausal or surgically sterilized) must be willing to use an acceptable method of birth control (i.e., hormonal contraceptive, intra-uterine device, diaphragm with spermicide, condom with spermicide, or abstinence) for the duration of the study. Should a woman become pregnant or suspect she is pregnant while participating in this study, she must inform her treating physician immediately. * Able to understand and willing to sign an IRB-approved written informed consent document (legally authorized representative permitted). Exclusion Criteria: * Leptomeningeal or metast…