A Senate ethics committee member predicted yesterday the panel will recommend that at least one senator in the "Keating Five" case be disciplined by the Senate and angrily criticized the panel for foot-dragging in concluding nearly two months of public hearings.

The prediction by Sen. Trent Lott (R-Miss.) was made as Sen. Alan Cranston (D-Calif.), one of five senators under investigation for ties to a savings and loan executive who contributed to their campaigns, waived his right to testify as he prepares for intensive new radiation treatment for prostate cancer.

The committee voted unanimously not to compel Cranston's testimony after his lawyer, quoting Cranston's physician at Stanford University Medical Center in California, said the senator was not strong enough to undergo even videotaped questioning.

The center later issued a statement in which Malcolm A. Bagshaw, head of its department of radiation oncology, said Cranston's tumor was "somewhat larger and more advanced than {those of} many of our patients." But Bagshaw added that Cranston stands an "excellent chance" of full recovery with the new treatment.

Lott, interviewed by reporters during the committee's lunch recess, did not identify the senator or senators most likely to be recommended for censure or other sanctions by the Senate. But the focus of the hearings has been on Cranston, Dennis DeConcini (D-Ariz.) and Donald W. Riegle Jr. (D-Mich.). Robert S. Bennett, the committee's special counsel, has recommended no further action against Sens. John Glenn (D-Ohio) and John McCain (R-Ariz.).

Riegle came under sharp questioning yesterday from panel members, including Jesse Helms (R-N.C.), who ridiculed the notion that thrift executive Charles H. Keating Jr. was not trying to buy influence with his fund-raising for lawmakers, which included $1.3 million for the five senators.

"My answer to that is, the hell he wasn't, and that's the perception of the American people," Helms said in questioning Riegle about a 1987 trip he made to Keating's corporate headquarters in Phoenix just before the senators met with regulators to discuss problems facing Keating's Lincoln Savings and Loan.

"I don't believe you would have gone out to Phoenix, I don't believe anybody would have been involved with Mr. Keating if he didn't have the ability to give away other people's money," added Helms, likening the cast of characters to the "Keystone Kops" and "Daddy Warbucks."

Committee Vice Chairman Warren B. Rudman (R-N.H.) also suggested a "remarkable inconsistency" in Riegle's visit with Keating in Phoenix despite Riegle's avowed policy of avoiding dealings with other senators' constituents. Riegle said he did so because of Keating's investments in Detroit and because Arizonan Earl Katz, who raised funds for him and DeConcini, proposed the visit.

Lott also questioned whether Riegle acknowledged an appearance of impropriety when, in light of meetings he attended involving Keating's problems, he returned $78,000 that Keating had raised for Riegle's 1988 campaign. Riegle, who has said he believes senators should be judged by their conduct and not appearances, said he returned the money after learning belatedly that it came from people with business connections to Keating.

Meanwhile, Riegle faced another challenge to his denial that he set up the first of two meetings with regulators on Lincoln's behalf when the committee released a deposition in which DeConcini, who will testify today, said Riegle and Keating both had "suggested" the meeting. Riegle testified Monday he had nothing to do with arranging the meeting.

In remarks to reporters during the committee's lunch break, Lott said he will be "amazed" if one or more of the senators are not recommended for disciplinary action by the Senate. "I would be amazed if in at least one case it did not go to the Senate floor," he said.

But Senate action is not likely before March because the committee has "just let {the hearings} drift along" through repetitive questions and testimony that have not been brought to a definite conclusion, he added, blaming himself as well as committee leaders for not hastening the process.

"I've never been through anything like this before," Lott said. He was a member of the House Judiciary Committee in 1974 when it considered the impeachment of President Richard M. Nixon, he said, and "this is worse."

Cranston, who has been undergoing treatment at Stanford since he gave an opening statement to the ethics committee in mid-November, has completed a seven-week course of radiation therapy and is scheduled to undergo surgery Jan. 21 for a radioactive implant. William Taylor III, his attorney, said Bagshaw has ruled out testimony by Cranston because the 76-year-old senator needs to recuperate from debilitating side effects of the first radiation treatment and gather strength for the surgery.