Brief Report: Bevacizumab for Brain Radiation Necrosis in Patients with Nonsquamous Non–Small Cell Lung Cancer

Introduction Recent advances in therapies based on molecular targeted agents and immune checkpoint inhibitors have prolonged the survival of non–small cell lung cancer (NSCLC) patients and increased the number of such patients undergoing radiotherapy for brain metastases. Brain radiation necrosis, a late adverse event of radiotherapy, occurs in ∼10% of these latter individuals. Whereas bevacizumab has shown efficacy for brain radiation necrosis, optimal treatment strategies have remained elusive. We here assessed the efficacy of bevacizumab for brain radiation necrosis in NSCLC patients. Patients and Methods In this retrospective study, we evaluated NSCLC patients treated with bevacizumab for brain radiation necrosis diagnosed on the basis of MRI or [11C]methionine-PET. The volumes of radiation necrosis and peripheral edema were measured. Results Four NSCLC patients were treated with bevacizumab for brain radiation necrosis. All four patients manifested neurological symptoms with radiation necrosis accompanied by peripheral edema. Histological analysis showed adenocarcinoma in all patients, with two harboring EGFR mutations, one a HER2 mutation, and one a KRAS mutation. The median radiation dose was 24 Gy, median time from radiation to bevacizumab treatment was 27 months, and median time from the start of bevacizumab treatment to radiological improvement was 5 weeks. Neurological symptoms improved in two of the four patients, and the dose of dexamethasone was reduced in three patients. The volumes of necrosis and peripheral edema in each patient were noticeably reduced by bevacizumab treatment. Conclusion Bevacizumab is an effective treatment for brain radiation necrosis in patients with nonsquamous NSCLC.