How does Gamma Knife treat metastatic brain tumors?
The gamma knife is a radiation delivery tool that is dedicated exclusively for the treatment of skull-based tumors and malformations. As such, it is very accurate – with sub-millimeter precision (<.3mm)- less than half the width of a human hair. So healthy tissue is spared while a cancer-destroying dose is delivered to the tumor. What makes a gamma knife so accurate and effective? The head is fixed in a frame that keeps the brain stable and unmoving. This head frame resembles that of a 'halo' apparatus used in neck injury patients. It goes on without much discomfort while the patient feels some pressure sensation once it is affixed. The other factor that aids in accuracy is the fixed isocenter of radiation - 201 sources of Cobalt -60 radiation that focus at a single point (fixed isocenter). The Gamma Knife of Spokane can reach multiple metastases, tumors found deep in the brain and tumors that are near critical structures in the brain with one single dose (thus the term 'radiosurgery'
