Late recovery of stereotactic radiosurgery induced perilesional edema of an arteriovenous malformation after bevacizumab treatment.

Purpose: Today, stereotactic surgery (SRS) is among the treatment options for many intracranial lesions including vascular pathologies. One of the most common late complications of SRS is perilesional edema which can be treated with steroids. In addition to steroids, some new medical therapies are being investigated and one of the promising one is Bevacizumab; a monoclonal antibody against vascular endothelial growth factor (VEGF). In the cases of steroid resistant perilesional edemas, however bevacizumab has a late term effect resolution of symptoms and radiological improvement can be seen as late as more than 1,5 years after its initiation. Materials and Methods: We present a 41-year old male patient who was admitted to our clinic with epileptic seizures, headaches and hemiparesis 14 months after SRS treatment for a left fronto-parietal Spetzler-Martin Grade III arteriovenous malformation (AVM). On his first-year follow-up perilesional edema was observed for which the patient received steroid treatment, but the patient did not show any benefit from it. In the cases of steroid resistant perilesional edemas, bevacizumab can be used for reducing symptoms and even radiological perilesional edema as well.Results: In our case, we have seen the effect of bevacizumab for symptomatic perilesional edema in a AVM patient after SRS treatment after radiological / neurological recovery. Our patient's headaches decreased rapidly after 2 days after treatment and was able to mobilize himself after 2 months but total resolution of symptoms and radiological findings observed after 1,5 years.Conclusions: The duration and optimum dose of bevacizumab therapy needed to further investigation. Our study showed that bevacizumab was a long-term and effective treatment option for the cases with peritumoral edema resistant to glucocorticoid treatment, where the patient had conditions such as severe headache and neurological deficits.