Intra-arterial Bevacizumab in Adult Patients With Steroid-Refractory Cerebral Radiation Necrosis: An Observational Study of Clinical Indications and Outcomes.

Background Cerebral radiation necrosis (RN) is a chronic inflammatory process that may develop following radiotherapy for a primary or metastatic brain tumor or arteriovenous malformation (AVM). A single infusion dose of intra-arterial (IA) bevacizumab (BV) is a viable option. The aim of this study was to assess the safety and efficacy of IA BV infusion in patients with steroid-refractory cerebral RN.  Materials and methods A total of 33 patients with imaging-confirmed brain RN underwent at least one IA BV infusion over a 9-year duration. BV was administered as a single 2.5 mg/kg (n=24) or 5.0 mg/kg (n=9) infusion dose.  Results Diagnoses included brain metastasis (17 (51.5%)), AVM (10 (30.3%)), and primary brain tumors (six (18%)). All patients experienced either complete relief or significant symptom improvement after the IA IV infusion. The initial brain MRIs performed following the IA BV infusion revealed a decreased size of the RN in all patients. Two patients had minimal side effects. Of the 16 (48.5%) patients who experienced an RN recurrence, 10 underwent a repeat IA BV infusion. The mean duration between the first IA BV infusion and last follow-up was 23.2 months (range: 0.1-85.2 months). Age (p = 0.00587), tumor pathology (p = 0.03509), and BV dosage (p = 0.02420) were significant predictors of RN recurrence. Conclusions IA infusion of BV was well-tolerated by all patients, with substantial clinical and radiological improvement. Further research is needed to explore additional factors that may impact the effectiveness of BV treatment in RN patients.