WASHINGTON (CNN) -- Massachusetts Sen. Edward Kennedy on Wednesday made his first appearance in Congress since being diagnosed with brain cancer nearly two months ago, casting a single vote to help break a Republican filibuster of an important Medicare bill.

Colleagues greeted Kennedy with a lengthy standing ovation on the Senate floor just after 4:15 p.m.

The bill would reverse a 10.6 percent cut in Medicare payments to doctors. The cuts in Medicare payments -- part of a scheduled cost-saving formula -- went into effect July 1, although the Bush administration said it will hold off processing claims until mid-July to give Congress time to reach a compromise.

In a written statement, Kennedy said, "I return to the Senate today to keep a promise to our senior citizens -- and that's to protect Medicare. Win, lose or draw, I wanted to be here. I wasn't going to take the chance that my vote could make the difference." Watch the senators applaud Kennedy's arrival »

A vote on the bill before the July 4 recess fell one shy of the 60 needed to clear a Republican filibuster and advance in the Senate.

Senate Republicans joined the White House in objecting to the Democratic-backed bill because it trimmed government support for private insurance programs that provide coverage to Medicare patients.

The private Medicare programs are a top policy initiative for Republicans. White House spokesman Tony Fratto says the president's senior advisers would still advise the president to veto the bill in its current form.

The vote to end the GOP filibuster on the Medicare bill was 69-30, nine more than the 60 votes needed and two more than needed to override a presidential veto. The senators agreed to consider the bill passed if the filibuster were broken.

Kennedy had surgery to remove a tumor June 2 and is now undergoing chemotherapy and radiation treatment.

Senate Majority Leader Harry Reid talked to Kennedy's wife, Vicki, twice since Sunday about having Kennedy return for the vote, the source said. Reid "was not pushing, just asking," the source said. Interactive: A closer look at Ted Kennedy »

Kennedy is chairman of the Health, Education, Labor and Pensions Committee and is an influential Democrat on health-care issues.

Some members of the Democratic leadership thought it would be a "great idea" if Kennedy were able to return because it would "buck up" Democratic senators who worked hard to pass the stalled bill, the source said.

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