1. Department of Neurosurgery, David Geffen School of Medicine of the University of California, Los Angeles (UCLA), Los Angeles, CA, USA.
2. Department of Radiological Sciences, Section of Neuroradiology, David Geffen School of Medicine of the University of California, Los Angeles (UCLA), Los Angeles, CA, USA.
3. Department of Head and Neck Surgery, David Geffen School of Medicine of the University of California, Los Angeles (UCLA), Los Angeles, CA, USA.
4. Department of Radiation Oncology, David Geffen School of Medicine of the University of California, Los Angeles (UCLA), Los Angeles, CA, USA.
5. Jonsson Comprehensive Cancer Center, David Geffen School of Medicine of the University of California, Los Angeles (UCLA), Los Angeles, CA, USA.