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23. Is
surgery necessary to diagnose a brain tumor?
Although a brain scan
can show an abnormality that looks like a tumor, the only way to determine
whether the abnormality is a tumor is by examination of a sample of the
abnormality under the microscope. Although there are many ways to obtain a
sample of a suspected tumor, with rare exceptions, all of them involve some
type of surgery.
Surgeons who operate
on the brain and spinal cord have several years of specific training and are
called neurosurgeons. A neurosurgeon interviews the patient,
examines the medical records and scans, and then discusses with the patient
the approach to determining the diagnosis. A neurosurgeon usually recommends
one of two approaches: a biopsy or a resection.
A biopsy is removal of
a piece of the tumor that will be examined by a pathologist. An open
biopsy involves removing a small amount of the tumor by carefully
cutting through the scalp, skull, meninges, and the brain over the tumor. A stereotactic biopsy is the removal of a small piece of the tumor
using computer guidance. Often, the procedure involves placing a thin needle
through a tiny opening in the scalp and skull. The neurosurgeon will decide
which of these procedures is the most appropriate for the patient, depending
on many factors.
Some patients have
tumors that can be completely removed in a procedure called gross total
resection. If only part of the tumor can be removed because of its size
or location, the neurosurgeon may perform a partial resection.
Removal of all or part of the tumor provides enough cells for the
pathologist to examine under the microscope. When neurosurgeons describe a
tumor that can be safely removed, they refer to it as resectable.
An open biopsy or
resection that removes a part of the skull is called a craniotomy. In
most cases, the opening in the skull is replaced with the section of bone
that was removed to obtain the sample of the tumor. In a few cases, metal
mesh or another type of material is placed over the brain if the bone must
be removed permanently.
There are a few
instances that do not allow the examination of a piece of the tumor to
confirm the diagnosis. Tumors in the brain stem or spinal cord may be
difficult to biopsy because of the risk of damage to the blood vessels or
normal structures nearby. Metastatic brain tumors that have spread from
another cancer, such as a lung or kidney cancer, may be removed if the
neurosurgeon determines that the patient will benefit from its removal. Not
all metastatic tumors require biopsy to confirm the diagnosis if the patient
has already had a biopsy that determined the origin of the tumor. Finally, a
few tumors such as germinoma or primary central nervous system lymphoma, may
be diagnosed without surgery if there are tumor cells present in the spinal
fluid. Such patients may have a sampling of spinal fluid taken during a
spinal tap or lumbar puncture.
In all cases, remember
that a biopsy is needed to confirm diagnosis so that an appropriate
treatment can be determined.
Sometimes tumors are
found that appear to be so slow growing and have few — if any — symptoms. In
these cases, a biopsy can be delayed for months or years. In the unusual
circumstance that the patient is too ill to have any form of treatment, a
biopsy may not be recommended. The neurosurgeon is trained to make an
appropriate evaluation of the patient's circumstances and recommend surgery
only if absolutely necessary.
24. What are the
potential complications of a neurosurgical procedure?
The neurosurgeon will
discuss with you the potential complications of the procedure he
recommends. Although a biopsy may remove a smaller piece of the tumor than
a gross total resection, either procedure can be technically difficult
depending on the size and location of the tumor. Like all surgical
procedures, the possibility of bleeding, infection, and pain will be
discussed with you. In many cases, the risks of the procedure can be
minimized with careful planning and preparation.
For stereotactic
or needle biopsies, which remove only a tiny piece of the tumor, the
pathologist may determine that the biopsy is nondiagnostic. This
means that no definite conclusions can be made about the tumor after careful
review. In some cases, the small piece of tissue is crushed and the cells
are distorted. In other cases, the tumor cells are adjacent to normal cells,
and the biopsy needle removes only a sampling of normal cells. There is a
higher risk of a nondiagnostic biopsy if the sample removed is very small.
If a diagnosis cannot be determined, no treatment can be recommended;
therefore another biopsy must be done. This is extremely frustrating for
the pathologist, the neurosurgeon, and most of all, the patient.
More extensive
neurosurgical procedures, such as partial and complete resections, may be
needed to provide a sample of the tumor to the pathologist as well as
relieve pressure caused by the tumor. The difficulty of removing a tumor and
the possible risks of removing it depend on multiple factors, including the
size and location of the tumor, the blood vessels in and around the tumor,
and any previous surgery or radiation therapy performed on the same area.
Some elderly patients or patients in poor health may have heart or lung
problems that would prolong recovery from surgery. Although neurological
functions such as motor strength or coordination may become impaired
immediately following surgery, in many cases, these deficits resolve with
time and with rehabilitation. The risk of seizure following a neurosurgical
procedure is low in most patients; however, many neurosurgeons use
anti-seizure medication (anticonvulsants) routinely in the postoperative
setting.
25. I was
taken to my local emergency room and told that I have a brain tumor. The
neurosurgeon on call told me I would need surgery right away. Should I get a
second opinion before having an operation?
Second opinions can be
a good idea. Almost everyone who has to make a serious decision wants to
consider all the options carefully. No one wants to feel rushed into a
decision about surgery, but there are some tumors that cause
life-threatening symptoms or grow so quickly that surgery should be done as
soon as possible. As the patient, you need to know if you have a few days to
consider your options or to seek an opinion from another neurosurgeon.
Whenever possible you
should speak frankly to your neurosurgeon about your concerns. You should
tell him that you are considering a second opinion because of the
seriousness of the surgery. If your neurosurgeon has done a good job of
explaining why you need surgery right away, the type of tumor he thinks he
will find, and whether or not all or most of the tumor can be removed, you
should hear similar answers from another neurosurgeon. It is unlikely that
two experienced neurosurgeons will give vastly different answers to these
questions.
M.L's comment:
egarding a second
opinion would be: it depends. You may not need one or you may not have time
to get one. If you've had a seizure and your doctor thinks you may have a
glioblastoma, you may not have several days to look for a second opinion.
However, if speaking to another doctor makes you feel more comfortable, then
you should do so. These days, getting a second opinion is a fairly common
practice. In some cases, your insurance company may even require it,
especially if surgery is recommended. The most important thing to remember
is that you must be sure that it's safe for you to delay your treatment long
enough to obtain a second opinion. I was extremely fortunate to have an
excellent neurosurgeon. He referred me to other doctors who were also
excellent in providing my follow-up care.
26. Are
there some brain tumors that can be surgically cured? Is a tumor that cannot
be resected always incurable?
Some brain tumors are
surgically cured; one of the most common tumors, meningioma, may be
completely resected and cured. A number of other tumors, including acoustic
neuroma, central neurocytoma, subependymoma, dysembryoplastic
neuroepithelial tumor, to name a few, may not recur after complete
resection. Some tumors, even if not completely resected, grow back so slowly
that another operation may not be needed for many years. Tumors that are
completely resected and do not tend to grow back are considered benign.
However, benign tumors in certain locations in the brain may still cause
death if they cannot be safely removed.
Some tumors cannot be
resected surgically; nevertheless, if they respond to other forms of
treatment such as radiation therapy or chemotherapy, surgical resection may
not be necessary. Germinomas, lymphomas, and other tumors that commonly
occur in the deep structures of the brain are often difficult to resect.
Fortunately, many can be treated successfully with chemotherapy, radiation
therapy, or both.
27. I have seen two
neurosurgeons about surgery for my brain tumor, and both say my tumor can be
safely removed. One of them says he uses "MRI guidance" to remove the tumor.
What does this mean? Is there an advantage to using MRI to remove the
tumor?
There are several
types of image-guided or neuronavigation systems available to assist
the neurosurgeon in localizing and removing the tumor during surgery. Some
systems use MR images taken before surgery together with special "markers"
that are placed on the patient's head. The MR images appear on a computer
display in the operating room with the markers still in place corresponding
to the exact location on the screen. The neurosurgeon can then use a special
pointer to touch areas of the tumor that are seen on the patient's MRI. This
allows the neurosurgeon to precisely orient the instruments during surgery,
an advantage when the tumor is deep within the brain. Thus, a combination of
direct visualization and corresponding MRI imaging may allow the
neurosurgeon to remove more of the tumor safely.
Another type of "MRI
guidance" is intra-operative MRI, (Color Plate 9) which is now
available at a few centers. These operating rooms are designed to function
with an MRI scanner that can be used during the operation. Also, the
neurosurgeon is able to perform a “post-operative” scan while the patient is
still on the operating table to make sure the entire tumor has been removed.
Neurosurgeons who use
neuronavigation systems and intra-operative MRI may be able to remove tumors
that would otherwise be difficult to localize by direct vision alone. In
some cases, a more direct approach to the tumor can be planned, reducing the
length of the operation and the potential for neurological deficits.
28. One of the people in my support group says that she had "an awake
craniotomy" to remove her tumor. What is this procedure and why did her
neurosurgeon do this?
Some patients have a
tumor near a critical area of the brain, such as the center that controls
speech. Studies such as functional MRI (see Question 22) can demonstrate the
location of the speech center before the operation. During surgery, however,
many tumors appear to blend into the surrounding normal brain, so it is
still possible to damage the speech center when attempting to completely
remove the tumor.
In some hospitals and
research centers, the patient is allowed to awaken after the neurosurgeon
has opened the skull and dura, exposing the brain. The surface of the brain
is covered with markers that identify which areas of the brain are involved
in the production of speech. The patient may be given a series of words to
read during surgery, but if stimulation of an area of the brain shows that
the patient can no longer respond, the neurosurgeon knows that removing
tumor from this area will most likely damage the speech center.
An awake craniotomy
requires more time and preparation for the neurosurgeon and the operating
team. Patients who may benefit from awake craniotomy usually have tumors
that can be completely resected, or will respond to other therapy for any
parts of the tumor that must be left behind.
29. My neurosurgeon
said that if I have a certain type of tumor, he could place "Gliadel" wafers
in the brain after he removes the tumor. But he said that he won't know
until surgery what type of tumor I have, and that I have to decide before
surgery whether I want him to do this. If I have Gliadel wafers placed
during my surgery can I still have chemotherapy?
Gliadel is a
dissolvable wafer impregnated with a chemotherapy drug called carmustine
(also known as BCNU). The wafer is designed to release chemotherapy slowly
into the surrounding brain to treat microscopic tumor cells left behind
after surgery. Gliadel was developed for malignant glial tumors,
particularly glioblastoma, but has also been used for other primary brain
tumors. If your surgeon is anticipating, based on your scans, that you have
a malignant glioma, he may consider implanting Gliadel after he has resected
the entire visible tumor. Gliadel wafers are placed up against the walls of
the cavity where the tumor was removed, before closing the membranes, skull,
and scalp.
There are some
possible side effects of Gliadel implantation. Although very little of the
chemotherapy drug enters the blood stream, it is still possible that
chemotherapy leaking into the spinal fluid could affect how the wound heals
if the neurosurgeon could not achieve a tight closure of the dura. It is
also possible that Gliadel could increase the risk of seizures within a few
days of surgery. This can usually be avoided by taking anticonvulsant
medication. Finally, a few patients have more swelling of the surrounding
brain at the site of the tumor resection when Gliadel has been used.
Gliadel releases
chemotherapy into the brain for several days following surgery, but its
effects are not permanent. Some patients have continued treatment with
intravenous BCNU (the chemotherapy drug that is in the Gliadel wafer) after
surgery. While there is theoretically an advantage in continuing to treat
any residual tumor cells with BCNU, the intravenous drug — unlike the
chemotherapy wafer — affects blood counts and may cause other systemic
toxicity. Clinical trials have studied the use of Gliadel followed by other
drugs, including temozolomide (Temodar) and CPT-11 (Camptosar). There did
not appear to be an increase in the expected side effects with these
combinations.
Because Gliadel
contains chemotherapy, some clinical trials for brain tumor treatment do not
allow patients to participate if they have been previously treated with
Gliadel. The patients in a clinical trial are all similar. The trial results
could be difficult to interpret if some patients had received Gliadel and
others had not. If it is important to you to enter a clinical trial
immediately following surgery, you should discuss this with your
neurosurgeon before receiving Gliadel.
However, the
randomized trials of patients with glioblastoma who received Gliadel have
indicated that long-term survival is improved, and long-term survival may be
equal or better than the survival of patients who have had intravenous BCNU.
Gliadel is often covered by insurance but there is also a reimbursement
program for patients who do not have insurance. You can find out additional
information about Gliadel at www.gliadel.com.
30. On my
most recent MRI, my neurosurgeon told me that my tumor is growing back. I
asked him if I should have surgery again, but he told me that he would have
to discuss with my other doctors what treatment I could have following
surgery. Why does treatment after surgery have an impact on whether I should
have a second craniotomy?
As important as
surgery is, it may only achieve partial control of the tumor. This is
especially true for tumors that spread deep into the surrounding normal
brain that are impossible to remove completely. Tumors that cannot be
completely removed and grow relatively quickly require other treatments to
limit their ability to grow back.
For many patients,
conventional radiation therapy (see Question 33) cannot be repeated.
Therefore, if the tumor grows back after completing radiation therapy,
another type of treatment should be used after a second surgery to control
any microscopic tumor left behind. If residual tumor is allowed to grow
unchecked, the benefit of a second surgery is likely to be temporary.
31. At the
time of my surgery, my neurosurgeon said that all of my glioblastoma had
been removed, but then he said I would need more treatment to keep it from
coming back. Why do I still need therapy if the malignant cells were
removed?
Many common tumors,
including astrocytomas, oligodendrogliomas, and lymphomas, may appear to be
discrete, well-defined masses on MRI. Occasionally, the neurosurgeon will
observe a difference in the appearance of the tumor mass and the surrounding
brain, but as a rule, these tumors tend to "blend in" and infiltrate the
surrounding normal brain. Therefore, the appearance on MRI that the tumor is
completely resectable may be misleading. The neurosurgeon may remove all
clearly abnormal tissue, but he does not attempt to remove all of the
microscopic tumor cells that have spread through the surrounding normal
brain. Neurosurgeons who refer to a "gross total resection" are simply
referring to their ability to remove all tissue that appeared to be part of
the tumor.
Microscopic cells that
have spread away from the main tumor mass will continue to grow and must be
treated. If the pathologist determines that the tumor is a type that will
recur, follow-up treatment after surgery, such as radiation therapy or
chemotherapy, is recommended.
32. My neurosurgeon
suggested that I have physical therapy and occupational therapy to help me
recover from my weakness after surgery. What is the difference between
occupational therapy and physical therapy? Do I need both?
Achieving optimal
neurological recovery after surgery often means extensive rehabilitation.
Rehabilitation programs are available in the inpatient and outpatient
settings. Patients may receive rehabilitation while undergoing other therapy
such as chemotherapy or radiation therapy.
Rehabilitation
programs offer access to a variety of treatment professionals and
specialized equipment to help patients receive a structured program for
recovery. An initial evaluation by a neurologist specializing in
rehabilitation or a physiatrist, a physician who specializes in
physical medicine, is necessary to identify what should be included in the
rehabilitation program. The rehabilitation program is customized to the
patient's neurological deficits. Typically, brain tumor patients have a
thorough evaluation to identify physical deficits as well as cognitive
deficits. Therefore, most patients benefit from a multidisciplinary program.
Physical therapy
treats weakness, loss of coordination, and limited endurance. During
physical therapy, patients learn to walk unassisted, to use a cane or
walker, or to transfer safely from the bed to a chair or wheelchair.
Patients may be fitted with a brace or other supportive device to compensate
for weak or stiff limbs. Activities may begin while the patient is still
confined to bed recovering from surgery because even passive movement of the
limbs helps prevent complications such as blood clots and bedsores.
Occupational therapy
assists the patient in performing activities of daily living, such as
bathing, brushing teeth, cutting food, and dressing. Occupational therapists
may use recreational activities such as puzzles to help patients improve
their hand-eye coordination and cognitive function.
Other treatment
professionals that may be needed in a rehabilitation program include
speech therapists, recreational therapists, rehabilitation counselors, and neuropsychologists. Speech therapists evaluate speech
production and comprehension. In addition, speech therapists work with
patients who have difficulty swallowing. Recreational therapists engage
patients in leisure activities, such as cooking, arts and crafts, and music
therapy. These activities provide “play” to balance the “work” of physical
rehabilitation. Rehabilitation counselors assess the goals of the patient in
relation to the return to work and family life. Neuropsychologists
specialize in the effect of brain injury on behavior and cognition. They
help identify ways to re-learn certain skills as well as advise patients on
how to compensate for neurological functions that are impaired.
How a
Craniotomy Is Performed
A craniotomy ("cranio-"
meaning skull and "-tomy" meaning incision) is the process of surgically
"cutting" an opening into the skull. A craniotomy may be done for a number
of reasons, including repair of a blood vessel, removal of a blood clot, or
removal (resection) of a tumor. Performing a craniotomy on a brain tumor
patient is not necessarily synonymous with performing a resection. An open
biopsy, for example, allows the neurosurgeon to directly visualize the
surface of the brain before removing a piece of the tumor. A partial
resection involves removing a larger portion of the tumor, and a gross total
resection removes the entire visible tumor. All of these procedures
begin by first removing enough of the skull to visualize the underlying
brain and tumor.
The following account
describes what you would see during a craniotomy for gross total resection
of a glioblastoma:
Before entering the
operating room, the anesthesiologist sees the patient and inserts an
intravenous catheter. A sedative is administered and the patient is taken
to the operating room. The anesthesiologist and operating room nurses
prepare the patient for surgery, placing the patient on the operating table
and attaching monitors for temperature, heart rate, blood pressure, and
oxygen. The anesthesiologist inserts a hollow tube through the patient's
mouth into the trachea that will deliver oxygen throughout the procedure
while the patient is asleep.
The neurosurgeon and
his assistants position the patient's head in a head holder similar to a
vise. The scalp overlying the site of the tumor is shaved and the entire
area is scrubbed with surgical soap. The rest of the head and body are
covered with sterile surgical drapes.
The neurosurgeon cuts
through the scalp with a scalpel, carefully cauterizing small bleeding
vessels. The scalp and muscle flap created by the incision are peeled back
to expose the skull. The edges of the flap are clamped and covered with a
moist sterile cloth. A surgical drill is then placed against the surface of
the skull and four bur holes are cut, forming a square. A surgical saw is
placed in one of the holes and the four holes are connected, thus allowing a
portion of the skull to be temporarily removed. This piece of skull is
placed in a sterile salt solution until the end of the operation.
The tough, outermost
membrane of the brain, the dura, is cut with scissors to fold back to the
edges of the bone, exposing the surface of the brain. The tumor may be
visible from the surface of the brain. A deeper tumor may be localized by
ultrasound, intraoperative MRI, or another surgical navigation system. The
neurosurgeon carefully cuts through the brain overlying the tumor until
abnormal tissue is found. This tissue may appear different in color and
texture from the surrounding normal brain. The neurosurgeon removes a small
piece of the abnormal tissue for examination by the pathologist.
The pathologist
prepares the tissue by freezing it in a small block and then slicing it into
sections so the tissue can be put onto microscope slides. These tiny pieces
of tissue are then stained to reveal the structure of cells. Often, the
pathologist can determine immediately whether there is tumor present in the
sample, whether the tumor is benign or malignant, and whether it is a
primary or metastatic tumor.
If the pathologist is
able to make a diagnosis from the frozen section, the neurosurgeon is
informed of the result. The neurosurgeon may remove additional pieces of the
tumor for further analysis and permanent sections. If the neurosurgeon
decides that it is too dangerous to remove additional tumor, the procedure
is terminated. However, if the additional tumor can be safely removed or if
the removal of large portions of the tumor will reduce pressure on the
brain, the neurosurgeon may continue to remove as much of the tumor as
possible.
The neurosurgeon and
his assistant carefully inspect the brain for evidence of bleeding vessels,
cauterizing them and bathing the exposed areas of the brain with sterile
fluid. When the neurosurgeon is satisfied that all tumor tissue has been
removed, and that all bleeding has been controlled, the tumor cavity is
filled with a sterile salt solution and the dura is replaced over the brain.
The dura is stitched together with suture and checked for any tiny leaks
along the suture line. Small holes are drilled through the edges of the
piece of skull that was previously removed. This piece is then placed over
the dura. Holes are also drilled in the edge of the skull so that suture can
pass through both sets of holes to keep the skull piece firmly in place,
although some neurosurgeons prefer to use small metal plates and screws to
keep the skull piece in position. The muscle and scalp layers are then
sutured together and the free edges of the wound are finally sutured or
staped closed. A sterile dressing is then applied to the scalp.
The drapes are removed
and the anesthesiologist prepares the patient for awakening. The breathing
tube is removed and the patient is taken to the recovery room.
M.L's comment:
After I finally
mustered up the strength to read this section, it was all I could do to get
through it! When I think about the fact that this was done to me I almost
throw up, especially when I read that "a piece of my skull is placed in a
sterile salt solution." I also had no idea that the cavity in my brain where
the tumor used to be was filled up with "sterile salt solution." The part
that grossed me out the most was the description of how everything is
"stitched and stapled" back together. Somehow seeing neurosurgical
procedures on television documentaries isn't quite the same as imagining
that it's happened to your own head!
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