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About Brain Tumors
The brain is the center of thought, memory, emotion, speech, sensation and
motor function. The spinal cord and special nerves in the head called cranial
nerves carry and receive messages between the brain and the rest of the body.
There are two types of brain tumors:
- Primary — a tumor that starts in the brain. Primary
brain tumors can be benign (noncancerous) or malignant.
- Metastatic — a tumor caused by cancer elsewhere in the body that spreads
to the brain. Metastatic brain tumors are always cancerous.
Primary tumors in the brain or spinal cord rarely spread to distant organs.
Brain tumors cause damage because as they grow they can interfere with surrounding
cells that serve vital roles in our everyday life.
General Risk Factors for Brain Tumors
Most brain and spinal cord tumors have no known risk factors and occur for
no apparent reason. There are no known proven ways to prevent these tumors.
Facts about Brain Tumors
- The Central Brain Tumor Registry of the United States
estimates that more than 40,000 Americans will be diagnosed with a primary
brain tumor this year.
- This year, an estimated 170,000 Americans will be diagnosed with a brain
or spinal cord tumor that has spread from another part of the body.
Signs of Brain Tumors
No blood test or other screening exam can detect brain tumors, but there are
often some outward signs. While tumors in different parts of the central nervous
system disrupt different functions, some symptoms include:
- Headaches.
- Nausea/vomiting.
- Seizures.
- Weakness or numbness on one side of the body.
- Changes in vision, hearing or sensation.
- Difficulty with speech.
- Lack of coordination.
- A change in mood or personality.
- Memory loss.
Diagnosing Brain Tumors
If you suffer from any of the initial signs of a brain tumor, your doctor will
likely conduct some or all of the following tests:
- A physical exam to determine your overall health.
- A neurologic exam to evaluate brain and spinal cord
function.
- Imaging studies, such as CT, MRI or PET scans, to
look for signs of a brain tumor.
- If studies or scans indicate you might have a brain
tumor, some tissue may be taken from the tumor to make an exact diagnosis.
This test is called a biopsy.
- A spinal tap may also be performed to look for tumor cells. During this
test, a needle is placed in the lower back to obtain a sample of cerebrospinal
fluid. This fluid is then examined to see if tumor cells are present.
Treating Brain Tumors
If doctors determine that you have a tumor, the treatment options and prognosis
are based on the following factors:
- Tumor type.
- Location and size of tumor.
- Tumor grade (how abnormal the cells are).
- Your age, medical history and general health.
Understanding Radiation Therapy
Radiation therapy, sometimes called radiotherapy, is the careful use of radiation
to safely and effectively treat many different kinds of tumors.
- Doctors called radiation oncologists use radiation
therapy to try to kill tumors, to control tumor growth or to relieve symptoms.
- Radiation therapy works within tumor cells by
damaging their ability to multiply. When these cells die, the body naturally
eliminates them.
- Healthy cells near the tumor may be affected by radiation, but they are
able to repair themselves in a way tumor cells cannot.
Radiation Therapy Options for Brain Tumors
People with brain tumors should discuss treatment options with several cancer
specialists, including a radiation oncologist. A radiation oncologist is a doctor
who will help you understand the types of radiation therapy available to treat
your tumor. Conventional radiation therapy treatment options for brain tumors
include:
- External beam radiation therapy.
- Brachytherapy or internal radiation therapy.
External Beam Radiation Therapy
External beam radiation therapy involves a series of daily outpatient treatments
over several weeks to accurately deliver radiation to the brain. Radiation is
often given after surgery, and sometimes it is used instead of surgery.
- 3-dimensional conformal radiotherapy (3D-CRT)
combines multiple radiation treatment fields to deliver precise doses of
radiation to the brain. Tailoring each of the radiation beams to the patient's
tumor allows coverage of the brain tumor while keeping radiation away from
nearby organs, such as the eyes.
- Intensity modulated radiation therapy (IMRT) is the
most recent advance in the delivery of radiation. IMRT differs from 3D-CRT by
modifying the intensity of the radiation within each of the radiation beams.
- Stereotactic radiotherapy, sometimes called
radiosurgery, is a type of external beam radiation therapy that pinpoints high
doses directly on the tumor, in some cases in only one treatment.
- Proton therapy is given much the same way as external beam therapy, but
it uses proton particles rather than X-rays to kill brain tumor cells. This
treatment is only available in a few regions of the country.
Internal Radiation Therapy
Internal radiation therapy, or brachytherapy, works by placing radioactive
sources in or just next to a tumor.
- During brachytherapy, a tube or balloon called a
catheter will be inserted into the brain. The radiation will then be carried
to the tumor using this catheter.
- The radioactive source will then be left in place
from several hours to several days to kill the tumor cells.
- In some cases, the radiation is permanently placed directly into the tumor
or the area where the tumor was before surgery.
Newer Techniques
Doctors are constantly exploring new and better ways to treat primary brain
tumors.
- Drugs that make tumor cells more sens itive to
radiation are called radiosensitizers. Combining radiation with
radiosensitizers may allow doctors to kill more tumor cells.
- Chemotherapy is used with radiation to treat some brain tumors. Your doctor
may recommend that you consult with a medical oncologist (chemotherapy doctor)
before starting radiation.
Potential Side Effects
The effects of brain radiation can vary depending on your tumor and the technique
used to treat it.
- Before treatment, your radiation oncologist will
discuss any side effects — however rare — you may experience.
- Possible side effects can include fatigue, change in appetite, headaches,
visual changes, hair loss, skin irritation, nausea, vomiting and/or unsteadiness.
Some side effects can be treated with steroids or other medications. Talk to
your doctor about any problems you experience.
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