A brain tumor, known as an intracranial tumor, is an abnormal mass of tissue in which cells grow and multiply uncontrollably, seemingly unchecked by the mechanisms that control normal cells. More than 150 different brain tumors have been documented, but the two main groups of brain tumors are termed primary and metastatic.
Primary brain tumors include tumors that originate from the tissues of the brain or the brain's immediate surroundings. Primary tumors are categorized as glial (composed of glial cells) or non-glial (developed on or in the structures of the brain, including nerves, blood vessels and glands) and benign or malignant.
Metastatic brain tumors include tumors that arise elsewhere in the body (such as the breast or lungs) and migrate to the brain, usually through the bloodstream. Metastatic tumors are considered cancer and are malignant.
Types of Brain Tumors
There are many different types of brain tumors. This is a list of several of the most common.
These are very common benign brain tumors in adults. They arise along nerves, comprised of cells that normally provide the "electrical insulation" for the nerve cells. Schwannomas often displace the remainder of the normal nerve instead of invading it.
These are the most common glioma, accounting for about half of all primary brain and spinal cord tumors. Astrocytomas develop from star-shaped glial cells called astrocytes, part of the supportive tissue of the brain. They may occur in many parts of the brain, but most commonly in the cerebrum. People of all ages can develop astrocytomas, but they are more prevalent in adults — particularly middle-aged men.
This is the most invasive type of glial tumor. These tumors tend to grow rapidly, spread to other tissue and have a poor prognosis. They may be composed of several different kinds of cells, such as astrocytes and oligodendrocytes. GBM is more common in people ages 50 to 70 and are more prevalent in men than women.
Surgery is the usual treatment for most brain tumors. To remove a brain tumor, a neurosurgeon makes an opening in the skull. This operation is called a craniotomy. Whenever possible, the surgeon attempts to remove the entire tumor. If the tumor cannot be completely removed without damaging vital brain tissue, your doctor may remove as much of the tumor as possible. Partial removal
helps to relieve symptoms by reducing pressure on the brain and reduces the amount of tumor to be treated by radiation therapy or chemotherapy. Some tumors cannot be removed. In such cases, your doctor may do only a biopsy. A small piece of the tumor is
removed so that a pathologist can examine it under a microscope to determine the type of cells it contains. This helps your doctor
decide which treatment to use.
Sometimes, a biopsy is done with a needle. Doctors use a special head frame (like a halo) and CT scans or MRI to pinpoint the exact location of the tumor. The surgeon makes a small hole in the skull and then guides a needle to the tumor. Using this technique to do a biopsy or for treatment is called stereotaxis.
Other advanced techniques during surgery include brain mapping to find functional pathways near tumors, endoscopy to perform biopsies and open spinal fluid pathways through a small scope and advanced frameless stereotaxic computer assisted tumor
resections. Intraoperative MRI also is available to help maximize tumor removal.
Radiation therapy, also called radiotherapy, is the use of high-powered rays to damage cancer cells and stop them from growing. It is often used to destroy tumor tissue that cannot be removed with surgery or to kill cancer cells that may remain after surgery. Radiation therapy also is used when surgery is not possible. Radiation therapy may be given in two ways. External radiation comes from a large machine. Generally, external radiation treatments are given five days a week for several weeks. The treatment schedule depends on the type and size of the tumor and your age. Giving the total dose of radiation over an extended period helps to protect healthy tissue in the area of the tumor.
External radiation may be directed just to the tumor, the surrounding tissue or the entire brain. Sometimes the radiation is also directed to the spinal cord. When the whole brain is treated, the patient often receives an extra dose of radiation to the area of the tumor. This boost can come from external radiation or from an implant.
Radiation also can come from radioactive material placed directly in the tumor, or implant radiation therapy. Depending on the material used, the implant may be left in the brain for a short time or permanently. Implants lose a little radioactivity each day. The patient stays in the hospital for several days while the radiation is most active.
The Gamma Knife, or stereotactic radiosurgery, is another way to treat brain tumors. The Gamma Knife isn't actually a knife, but a radiation therapy technique that delivers a single, finely focused, high dose of radiation precisely to its target. Treatment is given in just one session. High-energy rays are aimed at the tumor from many angles. In this way, a high dose of radiation reaches the tumor without damaging other brain tissue.
Chemotherapy is the use of drugs to kill cancer cells. The doctor may use just one drug or a combination, usually giving the drugs orally
or by injection into a blood vessel or muscle. Intrathecal chemotherapy involves injecting the drugs into the cerebrospinal fluid.
Chemotherapy is usually given in cycles. A treatment period is followed by a recovery period, then another treatment period and so on. Patients often don't need to stay in the hospital for treatment and most drugs can be given in the doctor's office or clinic. However, depending on the drugs used, the way they are given and the patient's general health, a short hospital stay may be necessary.
Advances in chemotherapy include direct placement into the tumor cavity using a new technique called convection enhanced delivery.
Long-term Effects- Cognitive, Emotional and Psychological
Removal (resection through surgery) or external treatment of a brain tumor can have lasting, enduring effects and many brain tumor survivors may have long-lasting cognitive deficits and/or challenges. Depending upon the type of tumor diagnosis and the treatment of the brain tumor, residual effects may occur. These effects may include increased difficulty processing information, speech impairment, long and/or short-term memory deficits, impaired social skills, decreased level of functioning, and in some cases, personality changes and mental health challenges relating to anxiety and depression.
Ongoing neurological care, medication management, and maintenance with a Neurologist is the standard treatment following surgery. Patients may need medications based upon the results of treatment and/or residual physical, cognitive, and/or emotional challenges
that may result from their treatment. Patients may need follow-up testing, including blood lab work, EEG's, CT scans, PET scans, and other tests ordered by their physicians. Patients usually have follow-up visits with their neurologist approximately every three to four months and repeat MRIs or CT scans to check for any possible tumor re-growth (as ordered by their neurologist).