Even when small, these tumors can cause considerable swelling. In most cases, radiation is given to the entire brain with the hope of eliminating any small tumor deposits not yet seen on a scan. This can lead to memory loss and a decline in intelligence, so in most patients the highest radiation dose is limited to the tumor site. Avoiding these side effects is important for those with tumors with a fairly good prognosis , such as breast cancer.
The treatment of intracranial metastasis with stereotactic radiosurgery has shown great promise. This focused radiation can successfully control tumor growth. It offers the advantage of being able to treat multiple tumors at one time and can be repeated if new lesions develop.
Metastatic tumor cells can line the fluid cavities and surface of the brain. This is called carcinomatous meningitis. It can be disabling, and is treated by instilling chemotherapy into the spinal fluid. This can be done by lumbar puncture , or a specialized catheter can be placed into the ventricle of the brain and then connected to a small plastic reservoir placed under the skin. Drugs can then be injected into the reservoir to circulate throughout the spinal fluid.
