Proton beam therapy

Ashya King, a British boy with cancer, has already had a brain tumor removed. But he needs further treatment to kill off any remaining cancer cells.

His parents, Naghmeh and Brett King, were so desperate for their son to have proton therapy, they took him abroad against medical advice, prompting their arrest and subsequent release.

Now, Ashya could undergo proton beam therapy at a private clinic in Prague.

The clinic, which specializes in this "gentler" form of radiotherapy, has only just received official accreditation in the Czech Republic.

Elsewhere in Europe, including in the UK, proton beam therapy has struggled for state-level support.

And yet some call it revolutionary.

So what is proton therapy?

Sci-fi cyclotron for zapping tumors

The proton beam treatment room at Prague's high-tech Proton Therapy Center is impressive - it houses a huge circular device, rather like a massive MRI-scanner. Then they take you behind the wall to where all the real sci-fi stuff is.

A door opens into a cavernous room that feels like the interior of a planetarium, with a long silver tube suspended off the floor and disappearing into a tunnel.

It is along this tube that the protons are fired by a type of particle accelerator called a cyclotron.

They are then beamed into the cancerous cells of the patient lying motionless on a robotic gurney in the room next door.

Protons and photons

"The difference [between proton therapy and] conventional X-ray therapy is that the beam is composed of particles, positively-charged particles or protons," Dr. Branislav Sepesi, one of the center's radiation oncologists, told DW.

"Protons leave the whole energy and the whole dose in the tumor, whereas photons [used in conventional radiation] go through the whole body," Sepesi says.

As a result, proton therapy ensures that the radiation beam only penetrates the body as far down as the tumor, and goes no further, meaning it destroys far less healthy tissue.

It is, in effect, high-precision targeted radiotherapy, described as gentler and less prone to the side effects associated with conventional therapy, such as the chance of developing secondary cancers later in life.

The Prague Proton Therapy Center, which describes itself as the most modern in Europe, says it has the equipment and expertise to treat Ashya's cancer, called medulloblastoma.

Pernicious medulloblastoma is hard to treat

"We can say for 100 percent that we can treat Ashya, the small boy from the United Kingdom," says Iva Tatounova, the center's strategic director.

"Last week we received a letter with all the necessary documents about Ashya and his tumor, the medulloblastoma. Our specialists, physicists and doctors, in their consilium have reviewed the case," she explains.

Further consultations have since been held with doctors in Malaga - where Ashya was treated in hospital - and the UK.

Not available in Britain

Britain's National Health Service (NHS) does send patients abroad for proton therapy - 99 British children received the treatment last year, mostly in the United States.

But Ashya's doctors argued there was little evidence in his case that proton therapy would be more effective than conventional radiotherapy, because his whole brain and spinal cord has to be irradiated to wipe out any cancer cells.

That view is not held by the Prague center's oncologists, who say proton therapy is always preferable to treat medulloblastoma in children, even if - as they predict - Ashya may have to undergo up to 30 doses, or fractions, of proton therapy over five to six weeks.

And that's after undergoing chemotherapy at Prague's Motol Hospital first.

Running below capacity

So far the private clinic has treated several hundred people, well below its annual capacity of 2,000.

But Iva Tatounova believes that will increase as the treatment becomes more recognised by oncologists and the insurance companies which will have to pay for it.

And there's the rub - it is expensive. Ashya's treatment will cost about 80,000 euros ($103,000) - less than in the US, but still a tidy sum of money.

"When my physician diagnosed me with early stage prostate cancer and said we'll put you on active observation, I said to myself - well, that's fine, but it's not going to go away - what's the point waiting?" says Joe Tuftnell, a 70-year-old Czech-born British man, who came to Prague last year for treatment at the center.

Lucky to see proton ad in Prague

"I was lucky to be in Prague, and I came across this treatment. I jumped on it within a week," he told DW, adding that his prostate specific antigen or PSA level - a marker for cancer - had fallen dramatically after the treatment.

"I didn't ask my physician, yes or no. He was a little bit put out because I didn't consult him. But now I see him maybe once every six months, and he's very interested, and he says - we'll watch you with a hawk's eye now," says Joe, who paid about 19,000 euros for his therapy.

Cutting edge

Even the oncologists at the cutting-edge Proton Therapy Center are keen to stress that firing protons at tumors is not a magic bullet for cancer.

It's only suitable for some cancers and it is not 100 percent risk free - it is merely gentler and more targeted than classic radiation therapy.

It's not even terribly new - proton therapy has been around for decades.

But it is increasingly being used in medicine, and does, say the experts, represent the future of cancer treatment.