Radiation attempts to reduce the size of the tumor or to halt its progreesion. Even if the neurosurgeon removes all the visible tumor, there are usually cells of the tumor that remain. Radiation targets these potential sources for tumor recurrance. Technology has improved the delivery of radiation so that normal brain can be spared of its effects. Precise delivery systems have been developed to optimally deliver radiation to the tumors - such as linear accelerators and gamma knife units.
Chemotherapy utilizes toxic drugs to kill cancer cells.
The drugs can be given orally, intravenously or directly to the cancerous tisue. Chemotherapy affects both cancer cells and normal cells, so side effects are common. Various medications and delivery systems have been developed to prevent or treat these side effects. Despite the numerous treatments for brain tumors, achieving a cure or long-term survival is rare for most types of brain tumors. Investigational therapies are currently being developed and tested in the clinical setting.