TUESDAY, June 3 (HealthDay News) -- Sen. Edward Kennedy
certainly was heroic as he underwent surgery Monday for a malignant
brain tumor while
partially awake. But he was no more a superhero than other
men and women who suffer from the same condition and are faced with
the same type of procedure to remove their cancer.
Experts say this type of brain surgery, when the patient is
conscious for at least part of the operation, is not uncommon.
"It's specialized for tumor surgeons, but it's highly warranted
in this type of tumor and would be considered the standard of
care," said Dr. John S. Yu, director of surgical neuro-oncology at
Cedars-Sinai Medical Center in Los Angeles.
"When the tumor is very close to very critical brain areas, such
as language or movement, a lot of surgeons will choose to do this
procedure aware," added Dr. Walter Jean, associate professor of
neurosurgery at Georgetown University Hospital, in Washington, D.C.
"You have to have a big enough center that the surgeon is
comfortable with this. Certain centers do it more than others."
And incredibly strange as it may seem, keeping patients awake --
or at least partially awake for part of the procedure -- is
critical, so crucial brain functions aren't destroyed.
Equally strange, the actual brain does not have the ability to
feel.
"The brain itself is not sensitive to touch," said Dr. Eugene S.
Flamm, professor and chairman of the department of neurosurgery at
Montefiore Medical Center and Albert Einstein College of Medicine
in New York City. "It controls all our sensation. You can
manipulate the brain and do what you have to do in the brain
without the patient being aware of it."
But the patient isn't awake throughout the whole surgical
procedure and certainly not while the scalp and skull are being
opened or closed -- these areas
can feel pain, as anyone who has hit their head on a sharp
edge can attest.
"The only painful part of the procedure is when you enter the
skin and bone, so the patient is asleep," Yu confirmed.
Patients are awakened from their sedated state, at least
somewhat, while the surgeons determine which parts of the tumor can
be safely removed without damaging vital nerve centers that control
functions such as speech, cognition and movement. During this
phase, the patient's head is completely immobilized in a rigid
frame, while the rest of the body just lays on a gurney, Yu
said.
During this awake period (lasting perhaps 30 to 40 minutes,
according to Yu), doctors essentially "map" the brain, stimulating
different areas with electronic probes to see how the patient
responds. Each person's brain is structured a bit differently, so
what works for one patient may not work for the next.
The parietal lobe of the brain, where Sen. Kennedy's tumor was
located, is involved with speech, so that appears to have been the
main concern of his team of specialists. But the front part of the
parietal area also abuts the sensory cortex, which is connected to
motor function, Yu explained.
"The only way you can really test speech enough to avoid the
critical speech areas is by waking up the patients and having them
perform certain speech tasks, such as naming objects and responding
to questions," Yu said.
"What you don't want to do is take something out and say, 'Now,
can you move your hand?' " added Flamm. "You want an early warning
system."
Areas that control critical functions are then physically tagged
with a sterile piece of paper and also located on an MRI,
Georgetown's Jean said.
It's not unusual for the entire operation to last four to eight
hours, said Dr. Paul Graham Fisher, the Beirne Family Director of
Neuro-Oncology at Packard Hospital at Stanford University. Even so,
surgeons are never able to remove all of the malignancy.
"These tumors are very infiltrative," Yu said. "The idea is to
get as much of it as possible, particularly those you can see on
the MRI. Then the parts you can't see with MRI are treated with
conventional therapies like radiation and chemotherapy."
"The data say clearly that if you can resect [cut away] a
substantial part of the tumor, it's much better than doing a biopsy
alone," Fisher said. "It gives better quality of life, more time to
the patient, and it also allows you to try other options. It opens
other doors."
After surgery, patients are usually asked to undergo
chemotherapy and radiation.
"The best treatment for brain cancer is if the primary cancer
can be removed without significant effect," said Dr. Jay Brooks,
chairman of hematology/oncology at Ochsner Health System in Baton
Rouge, La. "The standard treatment afterward is to be treated with
a combination of chemotherapy and radiation for about six weeks
followed by chemotherapy five days a month for about six months
afterwards."
Temodar (Temozolomide) is the chemotherapy drug of choice these
days. It's relatively new and has the advantage of being taken
orally, Brooks said.
More recently, Yu and other researchers have been making headway
with vaccines for this type of brain tumor. Yu and his co-authors
just presented results of a phase II study on Monday at the
American Society of Clinical Oncology (ASCO) annual meeting, in
Chicago. "We've identified that a strong immune response is
correlated with increased survival."
Other experts speculated that Sen. Kennedy may, in fact, already
be enrolled in a vaccine trial currently under way at Duke
University. "Having undergone surgery does make available other
options, including this trial at Duke," Fisher said.
Results from the Duke trial, also presented at ASCO, reported
median progression-free survival in patients receiving the vaccine
(along with chemotherapy) of 16.6 months, whereas typically such
patients might be expected to live only 6.4 months without a
recurrence of the disease.
Still, cancer experts said Kennedy faces a difficult
struggle.
Montefiore's Flamm said a patient with this type of brain tumor
typically dies in about a year. "Some patients will die in less
than a year, and others may live for two years," he said.
Dr. Ania Pollack, a neurosurgeon at the University of Kansas
Hospital in Kansas City, agreed. "Life expectancy for a man Senator
Kennedy's age with such a tumor is about 12 to 14 months," she
said.
More information
The U.S. National Library of Medicine has more on
glioma.