Proton beam therapy sessions have saved the life of five-year-old British boy Ashya King, his parents claimed after he was given the all clear from brain cancer.
Parents Naghmeh and Brett King sparked an international manhunt last August after they removed Ashya from Southampton General Hospital last August.
They took the boy to their holiday home in Marbella, Spain, where the parents were arrested and spent several nights in jail.
In pictures: Ashya King's case
In pictures: Ashya King's case
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Brett King, back left, and Naghemeh King, right, accompany their son Ashya King (5) center, as he arrives for pre-cancer treatment examinations at the Motol hospital in Prague, Czech Republic
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Ashya King (5) arrives for pre-cancer treatment examinations at the Motol hospital in Prague, Czech Republic
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Brett King, father of five year old Ashya King, talks to members of the press after holding a press conference at his lawyer's office in Seville, Spain
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Brett and Naghemeh King, parents of Ashya King, attend a press conference in Sevilla, Spain. The British parents are heading to see him at a hospital in southern Spain following release their from custody after United Kingdom authorities dropped accusations of child cruelty against them
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British couple Brett (L) and Naghemeh (2L) King leave Soto del Real Prision in Soto del Real, near Madrid, Spain
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Brett King leaving Soto del Real prison near Madrid, Spain after British authorities dropped the case against him and his wife for taking their son Ashya from Southampton General Hospital without the consent of doctors
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Naghemeh King leaves Soto del Real Prision in Soto del Real, near Madrid, Spain
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Ashya King in hospital with his mother
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Journalist work outside the Materno Infantil Hospital where Ashya King is hospitalized in Malaga, Spain
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Ethan Dallas and Sanjay Ganatra, friends of the family, deliver a petition of over 100,000 names calling for his parents' release from a Spanish jail
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Spanish judge Ismael Moreno arrives to the National Courts to take statement to the parents of Britain's five-year-old boy Ashya King, in Madrid, Spain
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Ashya King parents's lawyer, Juan Isidro Fernandez Diaz, arrives at the National court in Madrid
AP Photo/Andres Kudacki
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Spanish policemen stand guard as a police van carrying the parents of Ashya King arrives at the courthouse in Madrid
JAVIER SORIANO/AFP/Getty Images
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Ashya King’s parents after their court appearance
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Ashya King's father explained why he took his son to Spain in a video uploaded to YouTube
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This photo of Ashya King being examined by doctors in hospital was posted on Facebook by his brother, Naveed
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Ashya King and his brother Naveed
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Ashya King on a hospital bed
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A CCTV still issued by Hampshire Police of Ashya King with his father Brett King at around 4pm yesterday
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The exterior of Southampton General Hospital where Ashya King, who has a brain tumour was taken by his parents from the hospital without the blessing of doctors
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Hampshire Constabulary said there are 'serious concerns' for the life of Ashya King as he needs constant medical care. Officers said his parents - Brett, 51, and Naghemeh, 45, - boarded a cross-Channel ferry from Portsmouth to Cherbourg at 4pm yesterday with Ashya's six siblings
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Ashya King, who has a brain tumour and was taken by his parents from hospital without the blessing of doctors
Ashya was finally allowed to undergo the proton beam treatment, instead of radiotherapy offered on the NHS, in the Czech capital Prague after a long High Court battle.
What is proton beam therapy?
This is a form of radiotherapy treatment for cancer involving high-energy protons, which are hydrogen atoms stripped of their electrons. Proton particles penetrate the skin and release much of their energy at the site of the tumour, destroying the capacity of cancer cells to replicate.
What is the difference with conventional radiotherapy?
Conventional “external beam” radiotherapy uses X-rays or gamma rays, which are essentially beams of photons rather than protons. The fast-moving and energetic photons work in the same way as protons by causing breaks in the DNA molecule of cancer cells, which inhibits their ability to replicate. However, the big difference between the two forms of radiotherapy is that protons release about 80 per cent of their energy directly within a tumour, whereas conventional radiotherapy releases energy continually to the healthy tissues on both sides of the tumour.
What is the advantage of proton beam therapy?
It all comes down to a part of physics called the "Bragg Peak". A phenomenon of protons is that they can be “programmed” to stop at a specific distance within the body, which is where they will release most of the energy - the Bragg Peak. Conventional radiotherapy beams made of photons continue to release energy before and after passing through the tumour, thereby damaging the healthy tissues of the body and causing more, worse side-effects.