FUS Etoposide for DMG

Subjects will receive focused ultrasound sonication followed by once daily oral etoposide (50mg/m\^2/dose). Oral etoposide will be taken every day for 21 days, followed by one week of rest. For the first cycle, etoposide will be administered immediately following confirming of the blood brain barrier opening through contrast magnetic resonance imaging (MRI) which will occur within 4 hours of the focused ultrasound procedure. For subsequent cycles, etoposide will be administered immediately following the focused ultrasound procedure. Subjects may continue for a maximum of 4 cycles.

Focused ultrasound sonication will be performed a maximum of three times a week for two weeks with two weeks of rest.