Conditions: Constitutional Mismatch Repair Deficiency Syndrome; Lynch Syndrome; Malignant Glioma; Recurrent Brain Neoplasm; Recurrent Childhood Ependymoma; Recurrent Diffuse Intrinsic Pontine Glioma; Recurrent Medulloblastoma; Refractory Brain Neoplasm; Refractory Diffuse Intrinsic Pontine Glioma; Refractory Ependymoma; Refractory Medulloblastoma
Interventions: Procedure: Biospecimen Collection; Procedure: Conventional Magnetic Resonance Imaging; Procedure: Diffusion Tensor Imaging; Procedure: Diffusion Weighted Imaging; Procedure: Dynamic Contrast-enhanced MR Perfusion; Procedure: Dynamic Susceptibility Contrast-Perfusion-Weighted Imaging; Procedure: Magnetic Resonance Spectroscopic Imaging; Biological: Pembrolizumab
Sponsors: National Cancer Institute (NCI)
Recruiting