Cancer Survivors Network

Profile of Radiosurgery Options & When for Met to Brain
Stereotactic radiosurgery may or may not be appropriate for a condition. It may be used as the primary treatment or recommended in addition to other treatments that are needed. Only a treating neurosurgeon who operates radiosurgery equipment can make the evaluation as to whether someone can be treated. A neurosurgeon must always be present during treatment and should work with a radiation oncologist when the brain is being targeted.

RADIOSURGERY
Stereotactic radiosurgery uses a large number of narrow, precisely aimed, highly focused beams of ionizing radiation to destroy brain tumors. The beams are aimed from many directions circling the head, and all converge at a specific point the tumor. That method necessitates knowledge of the exact location of the tumor and of any critical brain structures between the tumor and the scalp. This treatment is planned so that each part of the brain through which the beams pass receives only a small amount of the total dose. At the same time, it allows for a large dose to be delivered to the tumor itself. Conventional, external radiation to the entire brain often follows the radiosurgery.

There are three methods of delivering stereotactic radiosurgery: Gamma Unit (Gammaknife), adapted linear accelerators (Cyberknife) and cyclotrons.

The size of the tumor is a determining factor in deciding whether stereotactic radiosurgery is appropriate. Is the tumor small having a diameter of about one inch or less (three centimeters)? If so, radiosurgery may be appropriate. Larger tumors require more beams of radiation. That results in a greater effect on normal brain tissue. Other factors need to be considered to determine if this form of treatment is appropriate.
Are there multiple tumors? If so, what is their size and location? It may be possible to treat as many as three or four tumors, depending on their locations. Has the diagnosis of metastatic brain tumor been confirmed by biopsy? If there was prior radiation, is there an increased risk of side-effects with this modality?

Stereotactic radiosurgery requires minimal hospitalization. There is no risk of infection, and it requires only a short period of time for recuperation. However, the results of treatment are not immediate and there is some risk of damage due to the radiation.
Stereotactic radiosurgery does not offer the opportunity for confirmation of the diagnosis.

Stereotactic radiosurgery may be useful as a boost to other forms of radiation therapy for metastatic brain tumors. The characteristics of those tumors appear to be ide