Abstract
Stereotactic radiosurgery (SRS) is a proven treatment modality for inoperable arteriovenous malformations (AVMs). However, the rate of radiation-induced necrosis (RIN) is as high as 10%. A 6-year-old female patient presented with severe headache, emesis, and syncope, and workup revealed a Spetzler-Martin grade 4 AVM with intraventricular hemorrhage and hydrocephalus. The patient underwent a right frontal ventriculostomy followed by a linear accelerator-based SRS of 16.9 Gy. At 19 years, she developed progressive neurological symptoms. Diagnostic magnetic resonance imaging (MRI) revealed a recurrent parietal AVM nidus. We delivered the linear accelerator-based SRS of 18.5 Gy to the AVM nidus. Within 9 months, she experienced episodic headaches and left-sided weakness and spasticity; symptoms were initially managed with dexamethasone. Follow-up MRI was notable for edema and nondetectable blood flow, consistent with RIN and AVM obliteration. The second course of steroids did not provide the symptom control. Persistent RIN was noted on MRI, and she had stigmata of steroid toxicity (centripetal obesity, depression, and sleep disorder). Two infusions of bevacizumab (5 mg/kg) were administered concurrently with a tapering dose of dexamethasone. The patient noted a near immediate improvement in her headaches, and 2 months following the second bevacizumab infusion, she reported a near-complete resolution of her symptoms and displayed improved ambulation. The development of RIN remains a noteworthy concern post-SRS of AVMs. While steroids aid with initial management of RIN, for persistent and recurrent symptoms, bevacizumab infusions serve as a viable treatment course, with the added benefit of reducing the likelihood of adverse effects resulting from prolonged steroid therapy.