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What types
of brain tumors are there, and who is likely to develop
them?
Generally speaking, brain tumors can be categorized
as benign (slow growing and noncancerous) and malignant
(rapid growing and cancerous). Secondary tumors–those
that originate in other parts of the body and then spread
to the brain–are more common than primary tumors, which
begin in the brain. Many types of brain tumors are named
for the cells from which they grow or their location
in the brain.
Malignant brain tumors do not commonly occur. They
make up only about 1.3% of all cancers in the United
States. These tumors can be found in people of all ages,
but particularly in adults between 55 and 65 years of
age and in children between three and 12. Men and Caucasians
are at a higher risk for brain tumor than other demographic
groups.
The question of why brain tumors develop remains
unanswered. Some possibilities include environmental
and occupational factors, a handful of inherited conditions,
abnormal or missing genes, viruses, a defective immune
system, and atypical fetal development.
Does severe
headache indicate the presence of a brain tumor?
Severe headache can usually be attributed to causes
other than a brain tumor. However, headache is a common
symptom of brain tumors, particularly when the
patient also experiences a loss of balance; nausea and
vomiting that is not associated with migraine; double
vision; or numbness. The constant headache that is worse
in the morning than in the afternoon may also indicate
the presence of a brain tumor.
There are several other symptoms of brain tumors:
seizures, loss of hearing or vision; difficulty with
speech; memory loss and a general sense of confusion;
inability to concentrate or reason; and even a stroke.
Women of child-bearing age may find that their monthly
periods have stopped, although they are not pregnant.
Because these symptoms are shared with many conditions
other than brain tumor, it’s imperative that medical
care be sought for an accurate diagnosis.
Brain tumors
are sometimes described as being "Grade 1".
What does this mean?
Once a brain tumor biopsy
is examined by a pathologist, the tumor is categorized,
or graded, based on its cell structure and rate of growth.
There are different grading systems, but one that is
commonly used has four grades. Grade
I tumors are slow growing, with cells that are near-normal
in appearance and are not malignant. Tumors with cells
that are slightly abnormal are classified as Grade
II. Grade III
tumors grow quickly, contain abnormal cells, and spread
to surrounding tissue. The most malignant type of brain
tumors, Grade IV,
contain aggressive, abnormal cells that reproduce quickly.
What is the
prognosis for people with brain tumors?
That depends on the type and grade of tumor and the
patient: Children and young adults generally tend to
fare better than older patients, and women better than
men. While the diagnosis of a brain tumor is serious,
there is hope on several fronts. Of all primary tumors–those
that originate in the brain–about half are benign and
can be treated successfully.
The Central Brain Tumor Registry, which collects
data on primary brain tumors, reports a two-year survival
rate for malignant brain tumors of 35.1 percent; a five-year
rate of 26.6 percent; and a 10-year rate of 22.2 percent.
However, those percentages are an average of several
malignant brain tumors; the survival rates vary greatly
depending on tumor type. For example, the five-year
survival rate for patients with pilocytic astrocytoma
is 86.9 percent; for patients with mixed glioma, 55.3
percent.
Still, there has been an encouraging increase in
survival rates over the years. Specifically, one study
published in 1998 found that the five-year survival
rate rose from 40 percent to 60 percent for patients
with medulloblastomas and from 45 percent to 65 percent
for patients with oligodendrogliomas.
Earlier diagnosis and technological developments
now being applied to brain tumor treatment have contributed
to this increased survival rate. With the use of computerized
tomography (CT) and magnetic
resonance imaging (MRI), physicians have more accurate
images of brain tumors than ever before. The technology
behind stereotactic
surgery, which provides a 3-D image of the brain,
enables neurosurgeons to precisely map to the tumor
site and remove as much of the tumor as possible. Similarly,
stereotactic radiosurgery
can access tumors that are not reachable with traditional
craniotomy. Additionally, for certain brain tumors,
chemotherapy can be directly delivered in the form of
"seeds" or wafers that are surgically placed
at the tumor site.
How are brain
tumors diagnosed?
Brain tumors are diagnosed through a combination of
physical exam and diagnostic tests. A neurological exam
assesses both a patient’s physical condition–balance,
sensory abilities, and muscle movement, for example–and
his or her mental status. Next, images of the brain
are captured by scanning techniques such as magnetic
resonance imaging (MRI) or computed
tomography (CT). In some cases, a physician may
order a cerebral angiography, which is an X-ray of the
brain’s blood vessels. A biopsy–where
a small section of the tumor is removed and examined
by a pathologist–can determine cancer cell type and/or
malignancy.
What
new surgical techniques are being used in the treatment
of brain tumors?
Technology and computers, when used by a highly trained
and skilled neurosurgical team, have revolutionized
the approach to brain tumor surgery.
During a traditional craniotomy, where the patient’s
skull is opened to expose the tumor area, the neurosurgeon
is guided by pre-operative scans and what he or she
is able to see at the time of the operation. Sometimes,
in an attempt to remove as much of the tumor as possible,
healthy tissue surrounding the mass is removed.
However, new techniques and tools are tools are
enabling brain tumor surgery to be less invasive and
more precise. At present, the Program is pioneering
what is expected to be one of the most significant advances
in image-guided neurosurgery: the use of intraoperative
MRI scans to confirm the location of lesions, plan
and reconfirm the optimal surgical approach, and verify
complete lesion removal prior to closure. University
Hospital is the second hospital in the world to utilize
a compact OR-based MRI system to obtain the most precise
image possible to minimize the risk of harming healthy
and/or eloquent areas of the brain. MRI images obtained
during surgery provides the surgical team with a navigation
route that adjusts for brain shift during the procedure.
Furthermore, it provides the surgeon with the opportunity
to safely expand the operative area if necessary for
maximum lesion removal.
Other techniques employed in the treatment of brain
tumors include stereotactic surgery, which uses computer-based
technology and MRI scanning to produce a three-dimensional
image of the patient's brain. A metal frame is attached
to the patient's skull to create a fixed reference point
or system of coordinates. These components enable precise
mapping of and navigation to the tumor site. Then, optimal
tumor resection is possible using a variety of surgical
devices attached to the frame. "Frameless"
stereotactic surgery provides the same precision but
uses a reference system created by "wands,"
plastic guides, or infrared markers instead of
the metal frame.
Another relatively new surgical technique, Functional
Image-Guided Surgery (FIGS), combines Functional
MRI (fMRI) scanning with frameless
stereotactic surgery to optimize the safety and
efficacy of treatment for patients with tumors located
in the cerebral hemispheres. While the MRI
is scanning, the patient performs a series of activities
and movements, such as reading a list or tapping fingers.
The areas of the brain that correlate to those movements
"light up" on the scan and create an image. This information
is sent to a computer located in the operating room.
Neurosurgeons use a special pointer positioned on the
patient’s head to guide incisions and skull openings
based on corresponding points of the MRI
image.
Once a tumor
is removed, how soon will it be known if the mass is
malignant or benign?
During surgery, a section of the tumor is quick-frozen
and then examined by the neurosurgeon. This "frozen-section"
method gives the doctor some idea of whether the tumor
is cancerous or not, but it is not the definitive word.
A detailed pathological report may take up to two days
or longer if the sample is sent to another laboratory
for further examination.
If a brain
tumor is benign, or noncancerous, why is it still a
cause for concern?
There’s a sense of relief when a tumor is benign, and
about half of all primary brain tumors are of this type.
Meningiomas,
benign tumors found in the brain’s membrane lining and
the spinal cord, account for between 15 % and 20 % of
all primary brain tumors. However, cancerous or not,
a tumor can create pressure on vital areas in the brain.
Most benign brain tumors are treatable with surgery
or radiation.
Why are some
brain tumor patients treated with surgery alone, while
others also undergo radiation or chemotherapy?
There is no one-size-fits-all treatment for brain tumors.
It’s true that some low-grade
tumors can be completely removed and cured by surgery.
However, high-grade
tumors (those that are the most malignant) tend to grow
and spread very rapidly. Radiotherapy is used to slow
the growth or reduce the size of tumors. While radiation
can be delivered conventionally–that is, by using external
beams aimed at the tumor–there are other techniques.
Brachytherapy
refers to radioactive "seeds" that are placed
at the tumor site. Stereotactic
radiosurgery can deliver high-dose beams to a very
precise location on the tumor.
Chemotherapeutic drugs destroy cancer cells and
are used to treat certain types of brain tumors. Chemotherapy
often is preferred over radiation in treatment of young
children with brain tumors, as radiation may have adverse
affects on the developing brain.
What are
some factors to consider when selecting a neurosurgeon
and a hospital for treatment of a brain tumor?
The referring doctor may give the patient the names
of a few neurosurgeons, and the insurance company also
may have some input based on which doctors are in its
coverage network. One critical question the patient
should ask is whether the doctor is board certified
in neurosurgery. To be board certified, the doctor must
have successfully completed an accredited residency
program as well as written and oral examinations. To
narrow the choice further, the patient may wish to contact
a local brain tumor support group and speak with people
who have gone through brain tumor treatment.
Selecting the facility where treatment will be
given is also important. Hospitals in an academic setting,
by design, have access to the latest technology, something
that is very important to the way brain tumors are treated
today. Some facilities, like University Hospital, have
specialized brain tumor programs that emphasize a multidisciplinary
approach to treatment.
What’s the
average length of hospitalization and recovery time
after brain tumor surgery?
A. Length of stay and recuperation depend on
the type of surgery being performed and the patient’s
condition prior to the operation. Generally speaking,
however, a routine procedure involving the upper section
of the brain may require a three- to four-day hospital
stay; when the lower brain is operated on, the stay
may be a day or two longer. Patients are encouraged
to resume their regular activities as soon as possible;
many are back at work within two to three weeks after
they are discharged from the hospital.
What are
some suggestions for telling family members about the
diagnosis of a brain tumor?
It is important that family members be told so they
can be informed and supportive during treatment and
recovery. Even young children should receive a simple,
honest explanation; otherwise, they may form a conclusion
that is worse than the actual situation.
Telling the family is not something the patient
has to do alone or without help. Some patients may wish
to have a family conference with a member of the healthcare
team in attendance; others may rely on clergy or a crisis
support group to help them decide how to tell their
family.
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About
the Brain & Brain Tumors
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