aDepartment of Neurology, Stanford University School of Medicine, Stanford, California

bCenter For Neuro-Oncology, Dana-Farber Cancer Institute, Division of Neuro-Oncology; Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA

Correspondence to Patrick Y. Wen, MD, Center For Neuro-Oncology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA 02215, USA. E-mail: [email protected]