DURHAM, N.C. ? After investigating his options with his trademark intensity, Sen. Edward M. Kennedy underwent 3 1/2 hours of risky and exquisitely delicate surgery Monday to cut out as much of his cancerous brain tumor as possible.

“I feel like a million bucks. I think I’ll do that again tomorrow,” the 76-year-old Massachusetts Democrat was quoted as telling his wife immediately afterward.

Dr. Allan Friedman, who performed the surgery at Duke University Medical Center, pronounced the operation a success and said it “accomplished our goals.” Up next: chemotherapy and radiation, aimed at shrinking whatever is left of the tumor.

“The main goal is to remove as much of the tumor as possible to give any other therapy that we do a better chance of working,” said Dr. John Sampson, associate deputy director of Duke’s brain tumor center.

The sole surviving son of America’s most glamorous and tragic political family was diagnosed last month with a malignant glioma, an often lethal type of brain tumor discovered in about 9,000 Americans a year.

Details about Kennedy’s exact type of tumor have not been disclosed, but some cancer specialists said it’s likely a glioblastoma multiforme – an especially deadly and tough-to-remove type – because other kinds are more common in younger people.

Cutting a tumor down to size – or “debulking” it – is extremely delicate because of the risk of harming healthy brain tissue that governs movement and speech. But Friedman, who is the top neurosurgeon at Duke and an internationally known tumor surgeon, said Kennedy should not experience any permanent neurological effects.

Doctors said Kennedy was awake for much of the surgery, which begins with opening the scalp and removing a piece of the skull to expose the brain. Sometimes, to avoid damaging areas that control speech, surgeons use a probe to stimulate parts of the brain, then hold a conversation with the patient.

In the following days, Kennedy will probably be given drugs to prevent brain swelling and seizures, which are possible complications of the surgery. The senator will also be closely watched for bleeding and blood clots, because strokes are also a risk. He is expected to return to Boston in about a week.

“After a brief recuperation, he will begin targeted radiation at Massachusetts General Hospital and chemotherapy treatment,” Friedman said. “I hope that everyone will join us in praying for Sen. Kennedy to have an uneventful and robust recovery.”