• Histopathologically confirmed, based on biopsy or surgical resection, glioblastoma, or grade 4 astrocytoma, as defined by the World Health Organization (WHO)

• Deemed clinically appropriate for long course radiation therapy concurrent with systemic therapy

• Biopsy or surgical resection performed ≤ 12 weeks prior to study entry

• Adequate hematological, renal and hepatic functions as defined by the following required laboratory values obtained within 14 days prior to study entry:

‣ Absolute granulocyte count (AGC) \> 1.5 x 109/L (1,500 cells/mm3)

⁃ Platelet count \> 100x109/L (100,000 cells/mm3)

⁃ Serum creatinine \< 1.5 times the upper limit of normal

⁃ Total serum bilirubin \< 1.5 times the upper limit of normal

⁃ Alanine Aminotransferase (ALT, or formerly serum glutamic-pyruvic transaminase (SGPT)) \< 2.5 times the upper limit of normal

⁃ and/or aspartate aminotransferase (AST, or serum glutamic-oxaloacetic transaminase (SGOT)) \< 2.5 times the upper limit of normal

• Expected survival ≥ 12 weeks

• Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1 or 2

• Able (sufficiently fluent in English) and willing to complete quality of life questionnaires; however, inability to complete the questionnaires will not make the patient ineligible for the study

• Sufficient estimated glomerular filtration rate (eGFR) of ≥ 30 mL / min/1.73 m2 to allow administration of gadolinium-based contrast agent; patients with eGFR \< 30 mL/min/1.73 m2 not on dialysis may be allowed on the study after discussion of risks and benefits and approval by study neuroradiologist(s)

• Completed written informed consent

• Patient must be accessible for treatment and follow-up