Radiation therapy kills brain tumor cells with high-energy x-rays, gamma rays, or protons. Radiation therapy usually follows surgery. The radiation kills tumor cells that may remain in the area. Sometimes, people who can't have surgery have radiation therapy instead.
Both external and internal types of radiation therapy are used to treat brain tumors:
-
External Radiation Therapy A large machine outside the body aims beams of radiation at the head. Because cancer cells may invade normal tissue around a tumor, the radiation may be aimed at the tumor and nearby brain tissue, or at the entire brain. Some people need radiation aimed at the spinal cord also. The treatment schedule depends on your age, and the type and size of the tumor. Fractionated external beam therapy is the most common method of radiation therapy used for people with brain tumors. Giving the total dose of radiation over several weeks helps to protect healthy tissue in the area of the tumor. Treatments are usually 5 days a week for several weeks. A typical visit lasts less than an hour, and each treatment takes only a few minutes.
-
Image-Guided Radiation Therapy (IGRT) Patients who cannot tolerate surgery for the treatment of spinal tumors now have an attractive alternative with the introduction of stereotactic body radiation therapy (SBRT) at Roswell Park Cancer Institute. With the acquisition of its new Trilogy® system, RPCI is the first treatment center in Western New York and one of only a handful in North America to offer SBRT. The treatment delivers very high doses of radiation, focused with pinpoint precision through the use of image-guided radiation therapy (IGRT).
-
Gamma Knife Roswell Park Cancer Institute is one of the first facilities in the world to be equipped with a Model 4C Gamma Knife. Used to treat both benign and malignant brain tumors, Gamma Knife surgery is a noninvasive, outpatient treatment that does not require general anesthesia. It targets tumors by hitting them all at once with 201 intersecting gamma ray beams. The precision of radiation delivery protects normal tissues near the tumor site and, for some kinds of tumors, makes the treatment more effective than standard radiation therapy.
-
Intensity-modulated radiation therapy or 3-dimensional conformal radiation therapy These types of treatment use computers to more closely target the brain tumor to lessen the damage to healthy tissue.
-
Stereotactic radiation therapy Narrow beams of x-rays or gamma rays are directed at the tumor from different angles. For this procedure, you wear a rigid head frame. The therapy may be given during a single visit (stereotactic radiosurgery) or over several visits.
-
Internal radiation therapy (implant radiation therapy or brachytherapy): Internal radiation isn't commonly used for treating brain tumors and is under study. The radiation comes from radioactive material usually contained in very small implants called seeds. The seeds are placed inside the brain and give off radiation for months. They don't need to be removed once the radiation is gone.
Some people have no or few side effects after treatment. Rarely, people may have nausea for several hours after external radiation therapy. The health care team can suggest ways to help you cope with this problem. Radiation therapy also may cause you to become very tired with each radiation treatment. Resting is important, but doctors usually advise people to try to stay as active as they can. Also, external radiation therapy commonly causes hair loss from the part of the head that was treated. Hair usually grows back within a few months. Radiation therapy also may make the skin on the scalp and ears red, dry, and tender. The health care team can suggest ways to relieve these problems.
Sometimes radiation therapy causes brain tissue to swell. You may get a headache or feel pressure. The health care team watches for signs of this problem. They can provide medicine to reduce the discomfort. Radiation sometimes kills healthy brain tissue. Although rare, this side effect can cause headaches, seizures, or even death. Radiation may harm the pituitary gland and other areas of the brain. For children, this damage could cause learning problems or slow down growth and development. In addition, radiation increases the risk of secondary tumors later in life.