In the summer of 2014, Ashya King and his parents boarded a ferry from the UK to France, sparking an international manhunt.
The five-year-old had been undergoing surgery to remove a brain tumour at Southampton General Hospital until Brett and Naghemeh took him out of NHS care.
They fled the UK so Ashya could receive cutting-edge private proton radiotherapy to try and kill his cancer for good. The search ended with the Kings in police custody in V茅lez-M谩laga, Spain.
They argued proton therapy 鈥� as opposed to radiotherapy 鈥� offered fewer toxic side effects and would help give their son not just a life, but also a future.
Ashya, from Hampshire, was declared cancer-free in March 2015 and returned to school in January last year. At the time, his dad urged GPs to listen to the surging number of families begging for proton therapy on the NHS: 鈥淎s parents you have a feeling as to how much your child could take and how much he couldn鈥檛 take.
“We knew our son was too weak to accept the traditional therapy.鈥�
Prague鈥檚 Proton Therapy Center, which handled Ashya鈥檚 case, say that before he arrived for treatment in 2014, they鈥檇 only admitted four UK patients since opening in 2012. They have now cared for 70 clients from the UK 鈥� all desperately seeking treatment not available at home.
Doctors expect a similar rise in the months and years to come 鈥� but since 2008 the NHS has only referred around 400 patients for treatment overseas.
That will change in 2018 as two new centres are built as part of a 拢250m project, one at the Christie in Manchester and one in London.
Until then, patients will still have to visit the likes of the Proton Therapy Center, which is considered the most advanced establishment of its kind in Europe.
In just shy of five years, it has treated more than 700 patients from 25 countries. Head of clinical physics Professor Vladim铆r Vondr谩cek, 42, is responsible for the machine targeting the 鈥渞ight place of the right patient, and with the right dosage鈥�.
鈥淧roton therapy, partly because of Ashya King, is going to become much more well-known in the UK and also countries such as Spain,鈥� he says.
鈥淸In the UK] you have a proton beam centre in Clatterbridge but its only focus is on [eye] tumours.
鈥淚n the first year we treated something like 100 patients, three years later it was around 700-800.
鈥淚n the Czech Republic we put it into legislation so this is a recognised treatment. More than five per cent of our patients are from the UK: on every course there are one, two or three [Britons].
鈥淚 think the Ashya King case sped up the process, but moving from photons to protons is now inevitable because facilities and equipment are becoming more accessible and cheaper: it鈥檚 not as big a load from a financial point of view but the treatment鈥檚 benefits are much higher.
鈥淢aybe if there had been no Ashya King case then it would have taken much longer for the UK to decide to build proton centres. But over 10 or 20 years, it would have started to happen anyway.鈥�
Proton therapy is similar to radiotherapy but carries fewer complications and a lower risk of side effects associated with the high toxicity of conventional radiation.
Typically used for hard-to-reach tumours that have not infiltrated the surrounding tissue, an accelerated beam of positively-charged particles – accurate to within millimetres – is used to attack cancerous cells over five or more sessions.
Vondr谩cek explained: 鈥淚n many cases involving conventional radiotherapy, being 鈥榗ured鈥� is only half the journey. In some parts of the body, you have to go through healthy tissues surrounding the tumour.
鈥淪o the main benefit of proton therapy is that you are protecting those healthy tissues and you can expect much lower toxicity of the treatment when using protons against photons.
鈥淚n general the process is the same: we have to prepare the patient, do the imaging and contouring, carry out the treatment planning then treat as precisely as possible. That is the same for all radiotherapy treatment.
鈥淲hat is particularly different in protons is that you have to be far more precise, and much more aware of everything that can happen. The treatment is very sensitive to anything you don鈥檛 do in the right way.鈥�
Vondr谩cek says proton beam therapy can be particularly beneficial to children: 鈥淕enerally we can say the people [proton therapy is particularly good for] are those who are young鈥� it gives a high probability of a cure. There is very low toxicity and the expectation of a long lifespan after the treatment. It鈥檚 not so beneficial for patients who have had a very bad prognosis.
鈥淭here have been successes in situations with head and neck patients, for example young women with breast cancer.鈥�
In 2014, a report by Portsmouth Safeguarding Children Board found the actions by Ashya鈥檚 parents had 鈥減ut him at risk鈥�.
But a High Court judge approved the move to take him to Prague and the NHS agreed to fund the treatment, which lasted six weeks and cost around 拢65,000.
Brett King added: 鈥淲e would hate for this to happen to anyone else. But we are so proud of him: he鈥檚 now the boy that we had before the operation. There are still a few issues – he is wobbly on his legs and his speech is a bit strained – but he is a fighter and prepared to try anything.鈥�
In the UK there are approximately 4,000 children diagnosed with cancer each year 鈥� the equivalent of 10 every day. The Department of Health hopes its 拢250m investment will be a big step towards solving the problem.
A study published in the journal Lancet Oncology last year endorsed claims made by both the King family and Proton Therapy UK. Researchers at Massachusetts General Hospital, USA, found proton beam therapy caused fewer side effects in child cancer patients compared with conventional radiotherapy.
A spokesman said: 鈥淎lthough there remain some effects of treatment on hearing, endocrine, and neurocognitive outcomes – particularly in younger patients – other late effects common in photon-treated patients, such as cardiac, pulmonary, and gastrointestinal toxic effects, were absent.
鈥淧roton radiotherapy resulted in acceptable toxicity and had similar survival outcomes to those noted with conventional radiotherapy, suggesting that the use of the treatment may be an alternative to photon-based treatments.鈥�
The study analysed 59 patients aged between three and 21 from 2003 to 2009.
The majority – 55 – of the patients had the tumour partially or completely removed through surgery, while all patients received chemotherapy as well as proton beam therapy.
Three years after treatment, 83 per cent survived without the cancer getting worse, falling to 80 per cent after five years.