Bevacizumab as an effective treatment for radiation necrosis after radiotherapy for melanoma brain metastases

Radiation necrosis (RN) is a potential late complication of radiotherapy for intracranial malignancy, which is often associated with significant neurological morbidity. Prolonged treatment with high-dose corticosteroids or surgical resection has been the standard care for RN, but protracted steroid use can lead to significant side effects and surgical resection is not always feasible. The antivascular endothelial growth factor monoclonal antibody bevacizumab induces clinical and radiographic improvements in RN, with overall good tolerance. However, evidence supporting its use for RN in melanoma brain metastases is minimal, likely secondary to concern for intracranial bleeding. Immunotherapy is now one of the most commonly used and effective therapies for metastatic melanoma. A higher risk of RN has been reported with immunotherapy, making alternative treatment for RN in this population a priority, especially as prolonged use of steroids may counteract the treatment efficacy of immunotherapy. We report on seven melanoma patients who developed RN after stereotactic radiosurgery with or without whole-brain radiation therapy who were treated with 2-6 doses of bevacizumab. All patients experienced improvements in symptoms and quality of life, with a concurrent improvement in imaging in six patients. Furthermore, bevacizumab was well tolerated and none of the seven patients experienced intracranial or extracranial bleeding. Our series suggests that in selected melanoma brain metastases patients, bevacizumab may be a safe and effective treatment for RN, especially for those who are undergoing immunotherapy, and should be further evaluated in a prospective setting.