NCMP-15. BEVACIZUMAB FOR THE TREATMENT OF CEREBRAL RADIATION NECROSIS: A RETROSPECTIVE COHORT STUDY

Abstract

Abstract BACKGROUND Cerebral radiation necrosis (RN) is a critical complication of radiotherapy for brain tumors. Treatment with corticosteroids provides suboptimal symptom relief, and may have considerable side effects. Small-scale studies support the use of bevacizumab, but systematic data from clinical practice on its efficacy and toxicity remain scarce. METHODS In this retrospective cohort study, we included consecutive patients with symptomatic RN that underwent treatment with bevacizumab in our academic neuro-oncology clinic. RN was diagnosed based on imaging, histology or both. The primary outcomes were reported neurological improvement during follow-up, the duration of response, the reported improvement on MRI, and radiological outcome according to RANO criteria. Other outcomes included reduction of dexamethasone dose and the occurrence of adverse events. RESULTS Of the 37 included patients (39 RN-episodes), the majority had a glioblastoma (n = 22) or other diffuse glioma (8), followed by brain metastases (4) or other (3). Clinical response was reported in 17 RN-episodes (43.6%) and lasted for a median of 13 weeks (IQR 6–32 weeks). Radiological improvement during follow-up was reported in 29 RN-episodes (80.6%). RANO-defined radiological responses included 1 complete response (3.4%), 7 partial responses (24.1%), 1 minor response (3.4%) and 17 stable disease (58.6%). In total, 36 adverse events occurred, most commonly venous thrombo-embolism, hypertension and dyspnea, with 8 grade III-IV complications and 2 deaths (grade V) which were possibly related to bevacizumab. Of 32 patients on dexamethasone, 9 (28.1%) had completely stopped its use at treatment cessation. CONCLUSION This observational study confirms that patients with cerebral RN can benefit both clinically and radiologically from bevacizumab treatment in a real-life clinical setting, although our results are more modest than previous literature suggests. The high prevalence of – sometimes severe – adverse events should be weighed against the possible clinical benefit when counselling patients about this treatment option.