The authors present a 21-year-old woman who has been receiving rapamycin for 5 
months for bilateral subependymal giant cell astrocytomas. The patient was 
started at a dose of 0.2 mg/kg/day. Levels were maintained between 11 and 13 
ng/mL. Magnetic resonance imaging of the brain 2(1/2) months after initiating 
rapamycin demonstrated a decrease in size of both astrocytomas (11 to 7.5 mm on 
the right and 8 to 5 mm on the left). Further studies are needed with prolonged 
observation to confirm these findings, determine the length of necessary 
treatment, and evaluate recurrence risk after discontinuation of rapamycin.