Metastatic Brain Tumors

Effective Metastatic Brain Tumor Treatment with Gamma Knife Surgery

Gamma Knife Surgery, which is actually not surgery but a non-invasive treatment using radiation, is one of the most effective treatments for metastatic brain tumors. Gamma Knife treatment provides between 84 and 97 percent local tumor control.

How Gamma Knife for Metastatic Brain Tumors Works

Using computer imaging, highly focused conformal radiation beams that are shaped precisely into the outline of the tumor based on an MRI scan of the brain are administered. This helps ensure that the metastasized (cancerous) tissue receives most of the radiation, with limited radiation to the brain. Gamma Knife surgery is best suited for tumors that are 3 to 4 centimeters or smaller. Patients with multiple metastases can be treated by Gamma Knife in one or sometimes several sessions.

Who Gets Metastatic Brain Tumors

This type of tumor is called a secondary brain tumor because it is actually cancer from another part of the body that has spread to the brain. Metastatic brain tumors can develop from cancer in any area of the body, such as the lung, breast, colon, kidney, or skin (melanoma).

Approximately 10 percent of all cancer cases will spread, or metastasize, to the brain. In Colorado, it’s estimated that approximately 20,000 new cases of metastatic brain tumors will be diagnosed this year.

The incidence of metastatic brain tumors is highest in those over age 65, but begins to increase at age 45. The rate of metastasis depends on the type of primary cancer. For example, malignant melanoma (skin cancer) metastasizes in nearly 50 percent of people — and more commonly in men than women — while digestive system cancers spread to the brain in fewer than 10 percent of patients.

Metastatic brain tumors are rarely diagnosed before the primary cancer cause is identified. Brain cancer is typically found during a brain scan (CT or MRI) that is ordered when a cancer patient exhibits neurological symptoms such as:

• dizziness
• headaches
• seizures
• memory issues
• problems with balance or speech
• personality changes
• blurred/double vision

Causes of Metastatic Brain Tumor

Metastatic brain tumors form from cancer cells that began elsewhere in the body. The cancer cells break off from the primary tumor and enter the bloodstream or lymph system to travel throughout the body.

Metastatic Brain Tumor Treatment Options

To determine the best treatment approach, doctors assess the growth and development of metastatic brain tumors based on:

• Your history of cancer and how your primary cancer is being managed
• Your overall health
• Number, size, and location of the metastatic brain tumor(s)
• Type of tissue or cells affected
• The likelihood that part or all of the tumor can safely be removed by traditional surgery
• The spread of the cancer within the brain or spinal cord

The three main types of treatment are surgery, chemotherapy, and radiation. Steroids and anti-seizure medications may also be used to help control symptoms.

• Gamma Knife Surgery has proven to be a highly effective method to treat metastatic brain tumors with reliable and predictable local tumor control and improved survival rates. Published medical studies involving more than 4,800 patients with brain metastases have found that Gamma Knife treatment offers consistent and reproducible results with an average local tumor control between 84% and 97%. Today radiosurgery is the primary management tool for intracranial metastatic disease.
• Surgery is often considered as a first option to remove the tumor if it can be reached without excessive damage to the surrounding tissues, nerves, and structures. Image-guided surgery helps increase precision, but hemorrhaging and surgical site infection are associated risks.
• Chemotherapy is not often used alone to treat metastatic brain tumors because of drug resistance and the blood-brain barrier. However, it may be combined with other treatment options.
• Whole Brain Radiation is sometimes recommended for patients with large lesions deep in the brain and for those with multiple metastatic tumors. It is also often used in combination with open surgery or Gamma Knife and other types of stereotactic surgery. However, because of its negative effects on cognitive function, a recent large study led by a researcher at The University of Texas MD Anderson Cancer Center found that the risks were greater than the benefits when used as an adjuvant therapy.

Benefits of Gamma Knife to Treat Metastatic Brain Tumors

• Extreme Precision: Allows a powerful dose of radiation to be delivered with no or minimal damage to healthy surrounding tissue and structures.
• No Incision: Results in fewer complications such as bleeding, infection, or cerebrospinal fluid leakage.
• Painless: Requires no general anesthesia, eliminating the related potential side effects.
• One-Time Treatment: Performed in a single session, often on an outpatient basis and only occasionally requiring an overnight stay.
• Repeatable: Potentially can be repeated once without risks if the tumor did not respond as expected or if the patient presents with more than one tumor.
• No Down Time: Patients can return to their normal activities almost immediately, with no rehabilitation necessary.
• Low Cost: Covered by most insurance plans and costs much less than traditional treatments.