• Stereotactic radiosurgery ("gamma knife") directs many precisely focused external radiation beams at a tumor .
Using these techniques, a high dose of radiation may be given to a tumor while the surrounding brain is
spared the adverse effects. These approaches require that the tumor be small to medium-sized and in an area of
the brain that could tolerate a radiation injury without causing the loss of an important function. This approach
has shown promise in the treatment of both primary and metastatic tumors and will likely play an increasing
role in the future.
Chemotherapy Chemotherapy can be effective when used before or after surgery and radiation. It
can be used at the time of diagnosis and for a recurrence . Some tumors in the brain can be exquisitely sensitive to chemotherapy, including germinomas, lymphomas and oligodendrogliomas.
A roadblock to treating brain tumors with chemotherapy is that the drugs do not easily pass through the blood vessels in the brain into the brain substance where the tumor is located. Some experimental approaches have investigated ways to open this blood-brain barrier with drugs, while others have attempted to directly inject drugs into the major arteries feeding a tumor. Research is focused on developing drugs that have increased specificity for brain tumors and that can easily cross the blood-brain barrier.
Biological Therapy Gene therapy is a new approach to treating brain tumors and relies on the
transfer of a new gene into tumor cells . The tumor then receives a new set of instructions.
