HSV G207 Alone or With a Single Radiation Dose in Children With Progressive or Recurrent Supratentorial Brain Tumors

Inclusion Criteria: * Age ≥ 36 months and \< 19 years * Pathologically proven malignant supratentorial brain tumor (including glioblastoma multiforme, giant cell glioblastoma, anaplastic astrocytoma, primitive neuroectodermal tumor, ependymoma, atypical teratoid/rhabdoid tumor, germ cell tumor, or other high-grade malignant tumor) which is progressive or recurrent despite standard care including surgery, radiotherapy, and/or chemotherapy. A pathologically proven secondary malignant tumor without curative treatment options is eligible. * Lesion must be \> 1.0 cm in diameter and surgically accessible as determined by MRI * Patients must have fully recovered from acute treatment related toxicities of all prior chemotherapy, immunotherapy or radiotherapy prior to entering this study. * Myelosuppressive chemotherapy: patients must have received their last dose at least 3 weeks prior (or at least 6 weeks if nitrosurea) * Investigational/Biologic agents: patients must have recovered from any acute toxicities potentially related to the agent and received last dose ≥ 7 days prior to entering this study (this period must be extended beyond the time during which adverse events are known to occur for agents with known adverse events ≥ 7 days). For viral therapy, patients must have received viral therapy ≥ 3 months prior to study entry and have recovered from all acute toxicities potentially related to the agent * Monoclonal antibodies: patient must have received last dose ≥ 21 days prio…