Focal radiation necrosis of the brain in patients with melanoma brain metastases treated with pembrolizumab

Introduction Up to 60% of patients with metastatic melanoma develop melanoma brain metastasis (MBM) during the course of their disease. Surgery, radiosurgery (SRS), stereotactic radiotherapy (SRT), and whole‐brain radiation therapy (WBRT) or combinations of these are commonly used local treatment modalities. Inhibitory monoclonal antibodies against the CTLA‐4 and PD‐1 immune checkpoint receptors significantly improved the survival of metastatic melanoma patients, including patients with MBM. This prolonged survival, and potentially also the immunostimulatory mechanisms, may expose patients to a higher risk for long‐term complications such as focal postradiation necrosis of the brain (RNB).