Inclusion Criteria:

• Age ≥ 18 years.
• Radiographic evidence or histopathologic confirmation of CNS malignancy, with or without prior resection.  .
• Planned (cohort 1) or completed (cohort 2) fractionated brain radiation. The therapeutic brain radiation treatment volume should exceed 30 cubic cm, including the volume of brain tissue occupied by infiltrative disease. Volume occupied by solid non-infiltrative disease (e.g., meningioma, metastatic disease, cystic cavity, resection cavity), should be excluded from the estimated treatment volume.
• Provide written informed consent for the current study and the Neuro-oncology biorepository for archiving of CSF and blood samples collected on this protocol.
• Expected survival >6 months and Karnofsky performance status ≥ 60.
• Willing and able to adhere with the protocol for the duration of the study including undergoing treatment and scheduled visits, and examinations.
• The following laboratory values obtained ≤14 days prior to registration:
  • Alanine aminotransferase (ALT) and aspartate transaminase (AST) < 3 x ULN (≤ 5 x ULN for patients with baseline liver disease);
  • Serum creatinine ≤ 1.5 mg/dL.
• Willingness to provide mandatory CSF and blood and able to undergo MRS/MRI with gadolinium.
• Male and female patients of childbearing potential must agree to use a dual method of contraception (a highly effective method of contraception in conjunction with barrier contraception) consistently and correctly from the first dose of study drug (Arm B only) until 90 days after the last dose of study drug.
• Ability to complete questionnaire(s) by themselves or with assistance.

Exclusion Criteria:

• Uncontrolled and/or intercurrent illness which limits safety of or compliance to study proceedings.
• Vulnerable populations: pregnant or nursing women (Arm B exempt), prisoners, mentally handicapped.
• Patients with recurrent brain tumor after prior radiation.
• Cohort 1 only: History of prior brain radiation, with prior cumulative target radiation treatment volume exceeding 2 cubic centimeters.
• Patients who do not have an implanted CSF access device (who would thus require multiple LPs for participation) should be excluded if they have any contra-indication to lumbar puncture. This includes but is not limited to Age ≥ 18 years.
• Radiographic evidence or histopathologic confirmation of CNS malignancy, with or without prior resection.  
• Planned (cohort 1) or completed (cohort 2) fractionated brain radiation. The therapeutic brain radiation treatment volume should exceed 30 cubic cm, including the volume of brain tissue occupied by infiltrative disease. Volume occupied by solid non-infiltrative disease (e.g., meningioma, metastatic disease, cystic cavity, resection cavity), should be excluded from the estimated treatment volume.
• Provide written informed consent for the current study and the Neuro-oncology biorepository for archiving of CSF and blood samples collected on this protocol.
• Expected survival > 6 months and Karnofsky performance status ≥ 60.
• Willing and able to adhere with the protocol for the duration of the study including undergoing treatment and scheduled visits, and examinations.    The following laboratory values obtained ≤ 14 days prior to registration:
• Alanine aminotransferase (ALT) and aspartate transaminase (AST) < 3 x ULN (≤ 5 x ULN for patients with baseline liver disease).
• Serum creatinine ≤ 1.5 mg/dL.
• Ability to complete questionnaire(s) by themselves or with assistance.
• Wllingness to provide mandatory CSF and blood and able to undergo MRS/MRI with gadolinium.
• Male and female patients of childbearing potential must agree to use a dual method of contraception (a highly effective method of contraception in conjunction with barrier contraception) consistently and correctly from the first dose of study drug (Arm B only) until 90 days after the last dose of study drug.

Eligibility last updated 4/5/22. Questions regarding updates should be directed to the study team contact.