Ashya King's Parents, Once Jailed for Seeking Alternative Cancer Treatment, Now Say He Is Cancer-Free

— -- The parents of a 5-year-old who were briefly jailed after taking him from a British hospital and seeking alternative cancer treatment in Europe now say he is cancer-free.

“We have saved his life,” Ashya King’s father, Brett King, told the Sun, a British newspaper.

“It justifies everything we went through. If we had left Ashya with the NHS we don’t think he would have survived," he added, referring to Britain's National Health Service.

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Ashya was diagnosed last year with medulloblastoma, a cancerous brain tumor located in the cerebellum, a part of the brain that controls motor functions. The child had a 70 to 80 percent chance of surviving five years, according to a statement from Southampton University Hospital, where Ashya was being treated before the family fled to Spain.

After surgery in England to remove the tumor, the boy’s father said he wasn't satisfied with hospital's treatment plan, which he called "trial and error." He researched treatments on the Internet and came up with what he thought was a better approach: proton beam therapy, a type of focused radiation therapy that uses protons, positively charged subatomic particles, rather than X-rays.

When the hospital refused to authorize or pay for the treatment, the parents took the boy and fled to Spain where King and his wife, Naghemeh King, were arrested, their son Naveed said in a YouTube video. They faced extradition back to the U.K., but British prosecutors quickly withdrew their arrest warrant and the family was able to seek treatment as they saw fit.

Neither Southampton University Hospital nor the family could immediately be reached by ABC News for comment.

The Kings ultimately sought treatment for their son at the Prague Proton Therapy Center in the Czech Republic. There he underwent about six weeks of treatment in September and October of last year, Iva Papounova, the director of the center told ABC News.

“Like the rest of the world, we heard the news today from the father that the latest scan shows the boy is cancer-free,” Papounova said. “We are thrilled to hear this.”

From a medical point of view it is too early to say the child is completely cured of cancer, Papounova said. Since its opening in 2012, the center has successfully treated hundreds of adults and about 60 children for all types of cancer, including cancer of the brain, prostate and lymphoma, she said.

“It works because it is more precise. It only targets the tumor, making it less harmful to the vital organs than conventional cancer therapies. Therefore you improve the quality of life of the patient,” Papounova explained.

Proton beam therapy has its supporters and detractors, noted Dr. John Suh, chairman of the department of radiation oncology at the Cleveland Clinic’s Taussig Cancer Institute.

“It may have some value for some cancers but right now it is very expensive,” Suh said. “We need clinical trials to do comparisons with conventional cancer therapies and to determine which cancers best benefit from it.”

The U.S. National Cancer Institute considers proton beam therapy "under investigation" for tumors like Ashya King's. MD Anderson in Texas and the Mayo Clinic in Minnesota are among American hospitals with proton beam therapy programs.

Papounova said she assumed the child is undergoing some sort of rehabilitation elsewhere and she did not expect him to receive additional treatment at the facility in the future. The fact that he is doing so well is a good sign, she said.

“He will be able to enjoy life as other people we have treated in the past have,” she said.