Study to Develop Head Stabilizer for Use During Brain Radiation Therapy

The purpose of this study is to begin to develop a device to stabilize the head during stereotactic radiosurgery (SRS). SRS is a therapy for brain disorders and cancers that uses a precise dose of radiation to treat a disease, and is different from whole brain radiation. This study aims to stabilize patient head motions during radiation therapy through the use of a special experimental head holder. The investigators would like to first see how the experimental device works in whole brain radiation.