Brain surgery, a form of neurosurgery known as a craniotomy, entails having a neurosurgeon cut into the brain in order to physically remove the metastasis and a small margin of surrounding tissue. Surgery is reserved for patients who present with a limited number (one or two metastases) of large or symptomatic brain metastases that have the potential for brain damage.
Some doctors will surgically remove up to two or three metastases, depending on their location. Surgery is typically followed by radiation therapy, either SRS or WBRT, as an extra protective measure to prevent recurrence in the same location.
When performed by experienced neurosurgeons, surgery has a very low complication rate. One important complication to ask your surgeon about is the risk of dispersing tumor cells to the meninges as a result of the surgery – this risk is typically very low, but may be especially relevant for tumors in an area called the cerebellum. A hospital stay of several days to a week is required, even without complications. In recent years, imaging technology has been developed that makes it possible to view the precise location of the metastasis and surrounding tissue, which helps avoid damage to areas of the brain that are important for speech, coordination, memory and other functions.
Surgery may be required if the diagnosis of brain metastasis is not certain, so that a biopsy can be performed on the tissue. About 1-10% of the time, the suspected brain metastasis can be something else like a primary brain tumor, a non-cancerous mass, or an infection. However, in some areas of the brain, such as the brainstem, it is too dangerous to perform surgery.