The targeted brain surgery like that chosen for Sen. Edward M. Kennedy is a delicate balance of removing as much of the tumor as possible, without harming healthy brain tissue that lets patients walk and talk.
Kennedy's surgeon Dr. Allan Friedman at Duke University Medical Center in North Carolina said the procedure to treat the senator's cancerous brain tumor “was successful and accomplished our goals.”
The 76-year-old senator now faces chemotherapy and radiation to treat the malignant glioma, a lethal type of brain tumor.
Kennedy underwent the six-hour surgery Monday after being diagnosed last month with one of the worst kinds of brain cancer.
Msnbc.com spoke with NBC chief science correspondent Robert Bazell for more information about the procedure and the senator's follow-up care.
Q. The operation reportedly will start with the patient heavily sedated as surgeons cut through the scalp and remove a small area of the skull bone to expose the brain. What else is involved in the surgery?
A. Kennedy was conscious during the 3½-hour procedure. This is a tool that’s frequently used during delicate brain surgeries.
It’s a low level of consciousness that they control with anesthesia very carefully. They obviously do everything they can to control the pain.
Doctors will electrically stimulate various parts of the brain with a small current to minimize the risk of cutting through anything that might affect speech, movement, eyesight, hearing or any of the critical functions that could be disrupted with surgery in this part of the brain.
Q. What is the chief risk from the surgery?
A. The biggest risk for taking something out of the brain is that it’s going to damage some essential function. A lot of depends exactly where the tumor is located and we don’t know that. Those details haven’t been released.
As with all surgeries there is the risk of infection and death. Those are very rare.
Clearly, someone who is 76 is at more risk of complications than someone who is 25. Also, with this type of cancer, the older a person, the more advanced it usually is.
Q. How long will he be hospitalized?
A. They expect him to be hospitalized for about a week. Over the next few days in the hospital they’ll be able to see if there was any damage to critical function like speech or movement.
Q. What will the follow-up treatment involve?
A. Kennedy now faces now faces chemotherapy in the form of a pill and radiation. There’s also a bit of chemotherapy that they’ll apply directly in the brain. The treatments are traditionally given as six-week courses. This kind of chemotherapy has side effects, but it’s not as severe as with other kinds of cancers, which can cause weight loss and severe nausea. With the radiation you have to shave the head to aim the beam carefully right at the area of the tumor.
At Duke and other centers there are also experimental treatments with different kinds of chemotherapy, if he doesn’t respond to the primary kind. There are also vaccines that are being tried with this kind of brain cancer. The idea of a vaccine is to minimize the chances of a recurrence. If it comes back, then it is often even more life threatening.