Brain metastases are tumors that have spread to the brain from another site such as lung, breast, melanoma and colon. Historically, the conventional treatment for brain metastases has been to deliver whole-brain radiotherapy, which requires the whole brain to be treated with radiation every day for approximately 2 1/2 weeks.
The side effects to whole-brain radiotherapy include hair loss, decreased memory, decreased mental activity and fatigue. Brain metastases treated with whole-brain radiotherapy have a high likelihood of returning, because the radiation dose is not high enough to permanently control these tumors.
Gamma knife radiosurgery is given in just one treatment, and greatly reduces the chance that the metastatic deposits will return. A very high dose of radiation is delivered very accurately and precisely to just the brain metastases.