BOSTON -- Sen. Edward M. Kennedy has completed the first phase of treatment for a malignant brain tumor at Massachusetts General Hospital.

A source who spoke on the condition of anonymity said that Kennedy’s treatment with radiation and chemotherapy was completed Friday.

Kennedy was diagnosed with a malignant glioma after suffering a seizure at his Cape Cod home on May 17.

Kennedy, 76, underwent a 3 1/2-hour surgery at Duke University Medical Center on June 2 to reduce his brain tumor in order to give more traditional treatment a chance to succeed.

His treatment regimen at Massachusetts General lasted approximately six weeks.

The outlook for patients with malignant gliomas is generally poor. Median survival for patients with moderately severe ones is three to five years, and less than a year for those with the most severe type.