A statement from the Massachusetts Democrat's office also said the operation was being performed by one of the nation's top neurosurgeons, Dr. Allan Friedman. He is "one of the thought leaders" and a giant in the field of neuro-oncology, Dr. Otis Brawley, chief medical officer of the American Cancer Society, tells the Associated Press.
Monday morning it was announced that the senator, 76, had checked into the North Carolina hospital Sunday night in anticipation of Monday's six-hour operation. The procedure reportedly began around 9 a.m.
It was expected that surgeons would attempt to remove as much of the tumor as possible while weighing the risk of harming healthy brain tissue that affects movement and speech.
"Many of us believe that the more you get out, the next treatments, whether they be radiation or chemotherapy, have a better chance of working because there's less tumor there to fight," explained Dr. Matthew Ewend, neurosurgery chief at the University of North Carolina, Chapel Hill.
Kennedy was expected to remain at Duke for one week's recuperation before seeking treatment at Massachusetts General Hospital, where he is scheduled to begin chemotherapy and radiation.
More Photos: See Ted Kennedy Covers