1. Department of Neurosurgery, Duke University School of Medicine , Durham, North Carolina , USA
2. The Preston Robert Tisch Brain Tumor Center, Duke University School of Medicine , Durham, North Carolina , USA
3. Duke University Medical Center, Duke Cancer Institute , Durham, North Carolina , USA
4. Central Brain Tumor Registry of the United States , Hinsdale, Illinois , USA
5. Center for Biomedical Informatics & Information Technology (CBIIT) and Division of Cancer Epidemiology and Genetics (DCEG), National Cancer Institute (NCI) , Bethesda, Maryland , USA