Physicians use the results of diagnostic tests to determine the site of the cancer and to stage it—or tell how far it has spread. This helps determine the outlook for recovery and the best course of treatment. Because brain/CNS tumors are often located near critical and/or sensory organs, patients should work together with their physician to choose among several treatment options that may be used alone or together, and understand the risks and benefits of each.
Surgery is the most common treatment for brain/CNS tumors, and often provides a cure. The goal is to remove as much of the tumor as possible without affecting brain function, often followed by radiation therapy to kill any remaining cancer cells. For tumors that have spread diffusely into nearby brain tissue, the goal of surgery is to reduce the amount of tumor that will need follow-up treatment with radiation or chemotherapy. Surgery can also help with symptoms related to the pressure of the tumor.
Chemotherapy (also called “chemo”) employs oral or injected drugs to kill cancer cells. These drugs enter the bloodstream and travel throughout the body, making the treatment useful for cancers that have spread to distant organs. However, many chemotherapy drugs are not able to enter the brain and reach tumor cells. For some brain/CNS tumors, the drugs may be given directly into the cerebrospinal fluid in the brain or into the spinal canal below the spinal cord. For brain/CNS tumors, chemotherapy is typically used along with other types of treatment such as surgery and/or radiation therapy.
Because chemo kills some normal cells in addition to malignant ones, it can cause side effects that vary depending on the type of drug used. These include, but are not limited to, fatigue, nausea, vomiting, loss of appetite, hair loss, mouth sores, changes in menstrual cycle and infertility. It can also cause low white blood cell and platelet counts resulting in higher risk of infection and easy bruising/bleeding. Although rare, some chemotherapy drugs used for brain/CNS tumors cause kidney damage and hearing loss.
Researchers are learning more about the gene changes in cells that cause cancer, enabling them to develop new drugs that specifically target these changes. These drugs work differently than standard chemotherapy drugs, usually with less severe side effects.
Stereotactic radiosurgery is a highly precise form of radiation therapy used primarily to treat small tumors and other abnormalities of the brain. It is a non-surgical procedure that delivers a single, high dose of precisely-targeted radiation using highly focused gamma-ray or x-ray beams that converge on the specific area(s) of the brain where the tumor or other abnormality resides, minimizing the amount of radiation to healthy brain tissue.
Radiation that kills or shrinks tumors may be used alone or in combination with other treatments, particularly to kill any cancer cells that remain after surgery. For brain cancer, radiation is typically a secondary therapy, but may be used as a primary treatment for brain tumors in difficult or critical locations in the brain. It can be delivered internally or externally. Side effects are usually limited to irritation around the radiation site, although many patients also report fatigue.
Brachytherapy With brachytherapy, radioactive seeds (pellets) are placed into directly into or near the tumor. The seeds give off small amounts of radiation over several weeks, and may be complemented by low doses of external radiation to treat nearby areas. This radiation method carries small risks associated with seed migration within the body.
External-Beam Radiation Therapy External-beam radiation is much like getting a regular x-ray, but with a much higher dose of radiation. Precisely-focused beams of radiation are focused on the affected area from outside the body. Therapy is administered five days a week for a defined number of weeks, depending on the size, location and type of tumor. This schedule allows enough radiation to get into the body while giving healthy cells time each day to recover. The treatment itself takes only minutes and is usually painless, but the proximity of tumors to critical structures in or near the brain can limit the effectiveness of traditional radiation therapy. External-beam radiation has been proven to be very successful in palliative treatment for cancer of the brain.
Intensity Modulated Radiation Therapy (IMRT) and Image-Guided Radiation Therapy (IGRT) IMRT/IGRT are rapidly replacing traditional external-beam radiation therapy for treating certain cancers. With daily CT guidance, they allows for more precise delivery of higher radiation doses to cancerous brain tumors while avoiding healthy brain and critical structures. IMRT/IGRT can also potentially shorten the duration of therapy and enable physicians to treat some brain/CNS tumors for which traditional radiation therapy was not an option.