The recent high profile case of British child, Ashya King, has sparked a war of words in the media and on social media between the parents on one side and the police and NHS on the other. Hampshire Police tweets said that the parents had broken the law by removing their son from hospital care and taking him abroad to raise funds for proton beam therapy. The hospital claimed never to have had any objection to the parents taking their child and paying for treatment in the Czech Republic. If the parents had not been so social media aware and pro-active, the story may have had a different ending. People in the UK seek private proton therapy treatment in the USA and Europe. France, the USA, Germany and Switzerland have had proton cancer treatment centres for some years. Two centres are under development in the UK. The NHS funds proton beam treatment for NHS patients in the USA, when the clinical team believe it is the appropriate treatment option. Proton beam therapy is a highly targeted type of radiotherapy that can treat hard-to-reach cancers, such as spinal or brain tumours. It has a lower risk of damaging the surrounding tissue and causing side effects than other treatments. Like regular radiotherapy, proton beam therapy kills cancer cells. But unlike X-ray beams, proton beams stop once they hit their target instead of carrying on through the body, which cuts the chances of damaging the surrounding tissues. Patients are often treated as outpatients, so they do not even have to be admitted to hospital. The number of sessions depends on the type of the cancer. There are two types of proton beam therapy- the low energy type used for eye surgery, where there are NHS and private clinics in the UK, and the high-energy type used to treat cancer, where the UK will not have any centres until 2018 - one in London and one in Manchester. Some doctors argue against them as each one costs over £100 million to build, and they are only suitable for less than 1% of cancer patients. Other doctors argue that the cost does not need to be that high and a much higher percentage of patients can be treated. The therapy is not available in the UK so British patients may travel to the US or Europe for treatment. The NHS pays for around 100 patients and families a year to be sent to the USA or Switzerland, at a cost of £100,000 each. From April 2018, the treatment will be offered to up to 1,500 cancer patients at hospitals in London and Manchester, and a future centre is planned for Birmingham. Most British patients seeking proton cancer therapy from the estimated 40 centres for themselves or their children, do so at their own cost. Most centres are in the USA and a few in Europe. The Prague Proton Therapy Centre is one of the newest in Europe and uses an ultra-modern application of proton therapy - pencil beam scanning. It accepts British patients for outpatient treatment. It is just a 2 hour flight from London, and has a UK office in Basildon, Essex. It claims to offer treatment at least as good as in the USA, for around a third of the US price and lower travel costs. The case is seen as a spark to light the debate about what cancer treatment the NHS offers in the UK and what the NHS should offer to patients for overseas treatment. Recent cross border cancer studies show that the UK lags behind many EU countries on various measures of cancer care, including survival rate.