A Vatican-hosted summit organized under the banner of "healing and renewal" for victims of sexual abuse by Catholic clergy members opened Monday with a keynote address defending Pope Benedict XVI.

Cardinal William Levada, a U.S. churchman who heads the Vatican's Congregation for the Doctrine of Faith, told a gathering of bishops from more than 100 countries that Benedict deserved gratitude for supporting U.S. bishops' efforts to fight the problem of pedophile clergy.

The Congregation for the Doctrine of Faith, the office that oversees cases of sexual abuse by priests, is the same Congregation that was held by Benedict before he became pontiff.

Although Levada conceded the church's handling of the problem was not perfect, he said Benedict has been vilified when he should instead be thanked for being "instrumental" in introducing rules to crack down on abuse by priests.

"The more than 4,000 cases of sexual abuse of minors reported to the CDF (the congregation on doctrine) in the past decade have revealed … the inadequacy of an exclusively canonical (or canon law) response to this tragedy, and on the other, the necessity of a truly multifaceted response," Levada said in his speech.

"The real question, of course, is going to be what happens once they go home? Is the Vatican going to sign off on this?" —John Allent, National Catholic Reporter

Dismissed by some as a PR stunt to repair the church's damaged reputation over years of scandal, the four-day symposium at the Gregorian University in Rome was also expected to be attended by the Vatican's chief anti-pedophilia prosecutor, Monsignor Charles Scicluna, as well as Irish abuse survivor Marie Collins, who was raped by a hospital chaplain when she was 13.

Collins, an outspoken advocate for Irish victims seeking justice against their abusers, has called on the Pope to restore their faith by asking for forgiveness on behalf of church hierarchy who covered up the crimes. Such a public gesture would be "wonderful," she said.

Collins will also share her personal story with the delegates.

Benedict did not attend the closed-door meeting. In a message sent on his behalf, the symposium was urged to continue consulting experts to promote "a vigorous culture of effective safeguarding and victim support."

John Allen, a Vatican correspondent for the National Catholic Reporter, told CBC News from Rome on Monday the meeting brings together clergy or laity "at the cutting edge" of fighting child abuse.

'Global standard' sought to protect children

"These are people who have been working on the issue for years, who have themselves often been frustrated with the institutional response of the church, and who have been trying to press it forward," Allen said.

He said the delegates will examine tough anti-child abuse policies adopted by bishops conferences around the world, including in Canada, and look to draw up a "global standard" to prevent further victimization.

Vatican sex crimes prosecutor Monsignor Charles Scicluna is expected to attend the four-day summit, which ends Feb. 9. (Pier Paolo Cito/Associated Press)

"But the real question, of course, is going to be what happens once they go home? Is the Vatican going to sign off on this? Will bishops conferences and other Catholic institutions around the world embrace it?" he added.

As part of the conference proceedings, a "penitential vigil" will be held in Rome's St. Ignatius Church, during which seven representatives of church groups that were responsible for abuses or failed to protect children will ask for forgiveness.

Freelance journalist Sabina Castelfranco, speaking to CBC News from Rome, said that ceremony will be presided over by the Cardinal of Canada, Marc Ouellet.

The conference, entitled Towards Healing and Renewal, will open Monday with a keynote address from Cardinal William Levada, a U.S. churchman who heads the Vatican's powerful Congregation for the Doctrine of Faith.

The office, which was previously run by Benedict before he became Pope, has jurisdiction over priest sex abuse cases.

With files from The Associated Press