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Brain Tumor
A brain tumor is any structure that takes up space. The term tumor may be used to describe a cyst, or, more commonly, an abnormal growth of cells. Abnormal growths of cells may represent a benign (non-cancerous) growth or a malignant (cancerous) growth.
There are two basic groups of malignant growths: brain tumors that start in the brain tissue itself (primary brain tumors) and tumors that spread from someplace else in the body (metastatic brain tumors). Metastatic brain tumors are described by their tissue of origin (lung, breast, kidney, etc.). Malignant primary brain tumors are described by their cell type and histologi appearance, both of which will determine the rate of growth of the tumor.
General types of brain tumors include: glioma, meningioma, adenoma and carcinoma. More than 40,000 Americans are diagnosed with a brain tumor each year. About half of these tumors are primary, half are metastatic.
Symptoms
Brain tumors are often difficult to diagnose because their symptoms may mimic other diseases. Symptoms may include:
 Headaches
Nausea and vomiting
Seizures
Blurred or double vision
Loss of hearing
Changes in behavior
Muscle control problems
Testing
The symptoms of a brain tumor may appear gradually, causing change as they evolve. There can be a long period of time from the beginning of symptoms to the actual diagnosis. Some tumors are more rapid in their growth and can cause symptoms quickly.
Testing for brain tumors is two fold. First, your doctor will ask you questions to get a complete history of symptoms, then will follow up with a basic neurological examination that will include tests on your 12 cranial nerves (eyes, ears, tongue, etc.) and the motor, sensory and balance functions as well as abstract thinking and memory tests. If the result of this examination leads your doctor to suspect the possible area of central nervous system involvement, additional diagnostic testing will be scheduled to define the lesion which is presumed to be a brain tumor. Such testing may include one or more of the following:
CT (Computed Tomography) scan
This is a combination of an x-ray device and a computer. X-rays are taken of the brain, and this information is fed into a computer which transforms the data into a picture. In some cases, the patient is injected with a special dye to make abnormal tissue more evident.
MRI (Magnetic Resonance Imaging)
This procedure uses a tunnel-shaped piece of equipment that contains a magnetic field and radio energy; no x-rays are involved. Magnetic signals are fed into a computer which assembles a picture. Because the MRI ignores bone which can obstruct CT images, this device provides a clearer picture of tumors located near the bone, and can provide a wider variety of image angles. It can detect edema (swelling), but has difficulty distinguishing edema from a tumor. MRI imaging takes longer than a CT scan, and is very noisy. Patients with cardiac monitors, pacemakers or surgical clips cannot take an MRI because of conflict with the magnetic fields.
EEG (electroencephalogram)
This test is used to record the electrical activity of the brain, particularly of the cerebral hemispheres, using electrodes attached to the scalp. Angiogram or arteriogram: This test, using an injection of contrast materials and a series of x-rays, shows the position of blood vessels near the tumor and the extent of the tumor*s blood supply. It is used primarily for pre-operative information rather than for diagnosis. This form of invasive arteriography is rapidly being replaced by MRI angiography at most medical centers.
Evoked potentials
This form of testing uses small electrodes to measure the electrical activity of nerves. This test is often used to provide a guide during the surgical removal of tumors growing around important nerves, such as optic nerves and acoustic nerves. Intraoperative ultrasound, which is simpler than other imaging techniques, is making it easier to see the edges of a tumor and therefore help make tumor removal surgery safer and more effective.
Biopsy
This is a surgical procedure used to remove a small amount of tumor tissue, which will then be analyzed by a neuropathologist. For those areas not easily reached through an open biopsy, a surgeon can precisely position a biopsy probe (through a small hole in the skull) in a three-dimensional space to allow access almost anywhere in the brain (stereotaxis biopsy).
Your nurse will talk with you about what these tests involve and how to prepare for them.
Treatment
Surgical
Surgery is usually the treatment of choice for accessible brain tumors. (Accessible tumors are those which can be surgically removed without causing severe neurological damage. Tumors located in grey matter or deep within the brain may be inaccessible. Inaccessible or inoperable tumors may be treated with radiation and/or chemotherapy.)
Surgical resection of a malignant brain tumor removes the tumor or reduces the number of tumor cells in the brain. The tumor is carefully dissected from normal brain tissue using a number of high-tech instruments or devices to help make the surgery safer and more effective. These may include the use of an operating microscope, ultrasound, ultrasonic aspirators and stereotactic procedures. The most commonly performed surgery for removal of a brain tumor is a craniotomy, in which the surgeon creates a window opening in the skull to access the tumor.
Stereotactic image-guided surgery allows the surgeon to pinpoint a specific target with greater accuracy than ever before, using three-dimensional coordinates and special instrumentation. It can be used to biopsy or remove deep brain lesions from areas that were previously inaccessible, with minimal trauma to the surrounding tissue.
Cortical mapping is a technique used during surgery to stimulate important areas of the brain around the tumor. This allows the neurosurgeon to safely preserve important brain function while removing the tumor.
Microsurgery is any surgery performed with the assistance of a microscope. It has improved several standard neurosurgical procedures, such as the removal of certain brain tumors, and has allowed for the removal of some tumors that previously were inaccessible or dangerous to remove.
Lasers, which use focused light energy, can be used in place of a scalpel to remove a tumor or destroy remaining tumor tissue.
Ultrasonic aspirators vibrate and break up tumors using sound waves. The aspirator then acts like a vacuum to remove the tumor fragments.
Implantable chemotherapy wafers are sometimes used in the treatment of more malignant brain tumors. These wafers are left in the brain after the tumor is removed to continue fighting the tumor cells.
Non-surgical
Radiology-guided microcatheters can be used to gain access to the blood circulation site for a tumor of the head or neck and then embolize it (cut off the blood flow to that area). Occluding the blood supply in this way can reduce the surgical risks or can be used as a palliative treatment to limit the tumor*s growth. The select access this process allows can also be used to precisely deliver high-dose chemotherapy.
Steroids control the swelling due to accumulation of fluids associated with brain tumors. They may be administered temporarily following surgery or during radiation to reduce edema, or they may be used long-term for relief of symptoms.
Chemotherapy uses special chemicals to poison tumor cells, which are more vulnerable to chemicals than healthy cells. It may be used before, during, or after surgery and radiation therapy. Dozens of new chemotherapeutic drugs are being studied and tested to determine their effectiveness in improving survival and recovery. If you meet the criteria for a clinical trial, your physician can offer you the option of participating in the research.
Stereotactic radiosurgery may be appropriate for patients who may also benefit from radiation, either conventional or focused (e.g., proton beam radiation which uses a finely tuned laser called a *gamma knife*). This treatment arrests tumor growth or may cause it to shrink, but will not remove the tumor entirely. For this reason, follow-up examinations (including periodic MRI*s) and observation are important to make sure the tumor remains under control. Radiosurgery is less expensive than microsurgery, and can be conducted on an outpatient basis. Many patients can return home a few hours after treatment and resume their normal activities with a minimum of side effects.
Radiation
This treatment is often used as follow-up after surgery to eliminate remaining tumor cells, or may be used to treat tumors that cannot be operated upon. Because many tumors are radio-sensitive, their cells die when exposed to radiation. Conventional radiation uses external beams of either x-rays or gamma- rays aimed at the tumor, a process conducted over several weeks.
Research
There is a great deal of ongoing research in the U.S. involving better and more effective treatments for brain tumors. As their effectiveness is proven, they will be incorporated through the Sentara Neuroscience Network. Promising areas of research include:
Gene therapy, a relatively new area of active cancer research, may lead to new treatments for (or prevention of) brain tumors. Proto-oncogenes are genes that direct normal growth and development. Alteration in these genes may activate them into oncogenes, which causes cancer.
Gene therapy research concentrates on identifying oncogenes and determining what series of events activates them.
Immunotherapy research, examining ways to stimulate and boost the body*s immune system.
Using monoclonal antibodies (multiple copies of a single antibody) to pinpoint and destroy specific tumor cells. Currently, scientists are looking at this application for treating widespread cancer rather than solid tumors. They can also be used in combination with tracers to make tumor cells more visible and improve the ability to diagnose brain tumors.
Ways to make chemotherapy more effective for brain and spinal cord tumors by overcoming what scientists call "the blood-brain barrier." This network of blood vessels and cells filters the blood to the central nervous system to protect and insulate these (CNS) tissues from potentially dangerous changes in the environment and compounds in the bloodstream. But this protective barrier can also prevent anti-cancer drugs from reaching their target, so scientists are developing drugs to help open the barrier.
Prevention
Scientists do not know what causes most primary brain tumors. Viruses, defective genes, and certain chemicals are all being explored and researched as possible culprits, but until the causes have been identified, there is no known way to prevent developing a brain tumor.
Support Groups/Resources
Many patients and families find great comfort and support in talking with other patients, families and caregivers who have had * or are having * similar experiences. Support group meetings are free of charge, and are facilitated by a trained peer or qualified professional.
For more information, or to find the support group nearest you, contact the following organizations:
The Brain Injury Association of Virginia
The National Brain Tumor Foundation
American Brain Tumor Association
The Brain Tumor Society
The American Cancer Society
The National Institute of Neurological Disorders and Stroke
The National Cancer Institute
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