A Phase I Study of AdV-tk + Prodrug Therapy in Combination With Radiation Therapy for Pediatric Brain Tumors

This is an Open label, Phase I, dose escalation study. Patients will receive an injection of AdV-tk into the tumor or tumor bed during the surgical procedure followed by 14 days of anti-herpetic prodrug, valacyclovir, starting 1-3 days after vector injection. Standard radiotherapy will begin 3-7 days after AdV-tK injection. Standard chemotherapy may begin after completion of valacyclovir at the discretion of the treating physician and family. Two dose levels of AdV-tk will be evaluated with a fixed dose of valacyclovir.