Could a dementia drug shield kids' brains from radiation damage?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Age 6 years to 21 years at time of study enrollment * Diagnosis of localized low grade glioma \[e.g., pilocytic astrocytoma, optic pathway glioma, ogligodendroglioma, ganglioglioma, pleomorphic xanthoastrocytoma (PXA)\], craniopharyngioma, ependymoma, or germ cell tumor * Initiating focal cranial radiation therapy (photon or proton) * Laboratory tests \[transaminases (ALT, AST, ALP), BUN and creatinine not greater than twice normal\] and normal ECG * Speak, read and understand English sufficiently to complete study assessments * Adequate vision and hearing for valid completion of study measures * Negative βHCG pregnancy test among females of childbearing age * Participant must be able to swallow pills (psychology staff will be available to assist with pill swallowing training if needed) * Parent/Legal guardian available and able to speak, read and understand English Exclusion Criteria: * Medical disorder that would endanger subject's well-being (e.g., uncorrected hypothyroidism, cardiac arrhythmia, hypertension requiring treatment, sick sinus syndrome, prolonged QTc) * History of significant neurological disease including poorly controlled seizures (i.e., \> 1 seizure per month; anti-epileptic medications are acceptable), stroke, or head injury with loss of consciousness * Psychiatric condition that would preclude or take precedence over study participation (e.g., active psychosis, suicidal ideation) * IQ below 70 based on baseline/screening assessment * Treatment with psychotropic medication (psychostimulant, antidepressant, anxiolytic, antipsychotic) within the past two weeks, unless being prescribed specifically as an anti-emetic * History of substance abuse * History of hypersensitivity or reaction to NMDA receptor antagonists * History of prior cranial radiation therapy