GBMs are the most common and most malignant of the
primary CNS neoplasms, representing 15% to 20% of these
tumors. Approximately half of all Astrocytomas are GBMs.
GBM is the most common supratentorial neoplasm in adults.
GBMs usually occur in patients over 50 and are unusual in
patients under 30. Like Anaplastic Astrocytomas, GBMs
can occasionally be found at any age; Anaplastic Astrocytomas and
GBMs are among the four most common primary Brain tumors in
infants and children under 2 years of age.
Various symptoms occur with GBM, including seizure, focal
neurological deficits, and stroke like syndromes.
The first symptom of a Brain tumor of any type can be a
headache, since these tumors act as masses within the boney
skull and thus cause increased pressure in the Brain. The headache
associated with a Brain tumor, is frequently worse in the
morning and is accompanied by vomiting. Other symptoms of a
Brain tumor can include seizures, weakness or numbness of a side
or part of the body, or such subtle symptoms such as changes in mood,
thinking or general state of well being. Sometimes increased pressure
in the Brain can cause blurred, double, or lost vision.
If a patient has any of the above symptoms, without any obvious
explanation, further work-up is warranted. These tumors can be
seen best by Magnetic Resonance Imaging (MRI) since the degree
of detail is much greater than that provided by CT scans. As with
other tumors and most particularly with any of the Gliomas, once
a mass is confirmed by any of the imaging techniques, the diagnosis
needs to be established by a biopsy of the mass. THE BIOPSY IS
USUALLY DONE IN CONJUNCTION WITH AGGRESSIVE RESECTION OF THE
TUMOR. The biopsy identifies the particularities of the tumor and
differentiates it from other types of masses, such as infection.
Along with primary CNS Lymphoma, GBMs have the worst prognosis
of all primary brain tumors. GBMs disseminate early, rapidly, and
widely. Central Nervous System spread is common, but distant
metastasis is rare.
In selecting the treatment of High Grade Malignant
Astrocytomas, it should be kept in mind that the following
three (3) statistically independent factors affect the length of
survival: 1) age at the time of diagnosis, 2) histological features
(Grade of the tumor and additional characteristics such as Mitotic
Index), and 3) performance status (the level of the patient's
Older patients with high grade malignant Brain tumors, who are
in poor neurological condition at the time of surgery, do less
The primary initial therapy is to gain control of the
increased Intracranial Pressure (ICP). Often times, these
patients have significant Brain swelling, in addition to the
presence of and as a consequence of the tumor. Pre-treatment with a
course of high dose intravenous steroids, may well improve the
condition of the patient prior to surgery. In some cases, this
may mean a strategic delay of surgical intervention for
three (3) to seven (7) days. The wait can be rewarded by a far
better initial outcome.
Aggressive surgical excision of the tumor is advocated in most
patients. The goal is to reduce the maximum amount of the tumor. In
some cases this may mean an extensive Frontal or Temporal Lobectomy.
When tumor is within the middle or posterior portions of the Temporal
lobe, the Parietal or Anterior or Middle Occipital Lobe, an aggressive
internal decompression of the tumor is warranted.
It is imperative to understand that there are surgical
limitations in the removal of these "infiltrative" tumors because they
"spread" along the interconnecting fiber pathways (tracts) of the
Brain. As such, these tumors can rarely be entirely removed
There are some advanced technologies that currently assist in the
extent of resection. The ability of the surgeon to "visualize" tumor
is somewhat limited. Magnification of vision, Intraoperative
ultrasound imaging, Intraoperative MRI scanning and Intraoperative
Fluorescence techniques (See Below) are a few of the
adjunctive technologies that may be available to assist maximum
resection, while limiting the risk of injuring adjacent functioning
FLUORESCENCE is one of the most advanced concepts for the
surgical management of an infiltrative Brain tumor and the ONLY
METHOD that permits the Neurosurgeon to visually identify the tumor
that infiltrates Brain tissue. This technique (developed primarily in
Europe) involves the ingestion of a medication (5-aminolevulinic acid
or "ALA" dissolved in water) that is taken up in certain molecules
of the tumor which when subjected to a special violet-blue light
beamed through the Neurosurgical Operating Microscope actually(
"lights up") glows. Once "seen" under the Neurosurgical Operating
Microscope, the surgeon can remove the fluorescent portion by using
any of several methods.
The Neurosurgeons of Neurosurgical Consultants firmly believe that
aggressive resection of the tumor, is the first definitive step in the
treatment of these tumors. The surgeon may choose to reserve
a small part of the tumor for tissue culture in the laboratory
followed by sensitivity testing against various chemotherapeutic
agents. It can be helpful to know beforehand, if a
certain drug has any or limited effectiveness against this particular
tumor, in this particular patient. These additional technologies
have helped to improve outcomes. We now routinely culture the tumor
and subject it to sensitivity testing against various chemotherapy
agents prior to initiating Chemotherapy.
Radiation therapy continues to have an important place in the
treatment of most of these patients and is the standard adjunct
therapy against which other treatments are compared.
Refinements have been made that make this treatment less toxic than
in previous years. For most patients, this will be the second major
treatment option, in a comprehensive therapeutic program.
Chemotherapy is the third arm of this comprehensive effort
to prolong and maintain a high quality of life. Traditional
management has been to use "standard" forms of chemotherapy. Currently
there are some unconventional chemotherapeutic alternatives that
offer considerable hope for improved quality and length of
survival. One of our
has utilized these newer medications such as Temodar
(temozolamide), Avastin (bevacizumab, an anti-angiogenesis agent) and
CPT-11, either alone (or more commonly) in combination or with
other drugs, to produce encouraging results. Additional information
regarding these treatments is available at the
In some tumor cases we choose to place a special chamber called an
"Ommaya Reservoir" under the scalp, with an attached catheter
residing in the "bed" of the tumor, after resection has been
completed. This permits the Neuro-oncologist to instill
chemotherapeutic medications directly into the tumor bed. This
is a far more effective methodology than placing "chemotherapy wafers
in the tumor bed.
There are several treatment concepts that have considerable interest.
Perhaps the most attractive is the potential availability of Gene
Therapy to treat Astrocytomas. Another very attractive
"surgical" application involves the selective susceptibility of
malignant tumor cells to beamed lasers. When this is
combined with "Fluorescence-guided" technologies, the surgical
management will be dramatically altered.
The following information at WebMD.com may also be useful:
Brain tumors, adult: Treatment - Health Professional Information (NCI PDQ) - General Information
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This page last edited on 2/19