Sen. Edward Kennedy's wife says he is fatigued but otherwise doing well midway through his radiation and chemotherapy treatments for brain cancer.

In an e-mail to family and friends sent Wednesday, Vicki Kennedy said her husband has been exercising each morning before heading to Boston for treatment at Massachusetts General Hospital.

By afternoon, he's back in Hyannis Port.The e-mail was obtained by The Associated Press today from a Kennedy friend.

Kennedy had a seizure at his Cape Cod home on May 17. He underwent surgery at Duke University Medical Center on June 2 and has been treated since in Boston.Vicki Kennedy says her husband describes his cancer as "as bear," but she thinks of his reputation as a political fighter and is "betting on the lion."