Radiation necrosis (RN) is a serious complication that can occur in up to 10% of 
brain radiotherapy cases, with the incidence dependent on both dose and brain 
location. Available medical treatment for RN includes steroids, vitamin E, 
pentoxifylline, and hyperbaric oxygen. In a significant number of patients, 
however, RN is medically refractory and the patients experience progressive 
neurological decline, disabling headaches, and decreased quality of life. 
Vascular endothelial growth factor (VEGF) is a known mediator of cerebral edema 
in RN. Recent reports have shown successful treatment of RN with intravenous 
bevacizumab, a monoclonal antibody for VEGF. Bevacizumab, however, is associated 
with significant systemic complications including sinus thrombosis, pulmonary 
embolus, gastrointestinal tract perforation, wound dehiscence, and severe 
hypertension. Using lower drug doses may decrease systemic exposure and reduce 
complication rates. By using an intraarterial route for drug administration 
following blood-brain barrier disruption (BBBD), the authors aim to lower the 
bevacizumab dose while increasing target delivery. In the present report, the 
authors present the cases of 2 pediatric patients with cerebral arteriovenous 
malformations, who presented with medically intractable RN following 
stereotactic radiosurgery. They received a single intraarterial infusion of 2.5 
mg/kg bevacizumab after hyperosmotic BBBD. At mean follow-up duration of 8.5 
months, the patients had significant and durable clinical and radiographic 
response. Both patients experienced resolution of their previously intractable 
headaches and reversal of cushingoid features as they were successfully weaned 
off steroids. One of the patients regained significant motor strength. There was 
an associated greater than 70% reduction in cerebral edema. Intraarterial 
administration of a single low dose of bevacizumab after BBBD was safe and 
resulted in durable clinical and radiographic improvements at concentrations 
well below those required for the typical systemic intravenous route. Advantages 
over the intravenous route may include higher concentration of drug delivery to 
the affected brain, decreased systemic toxicity, and a significantly lower cost.