The proton was discovered in Manchester by Sir Ernest Rutherford in the early 20th century. The potential for treating patients with protons was realised as long ago as 1946 when physicist Robert R Wilson described the potential use of the proton with its sharp Bragg peak to target tumours.
The first attempts to realise the potential of the proton to treat tumours were carried out in physics laboratories that had access to accelerators that could accelerate the protons to a high enough energy.
A good example of this is the Harvard Cyclotron Laboratory which initially was used exclusively for physics experiments when commissioned in 1949 but began treating patients in 1961. The Harvard cyclotron treated some 12,000 patients before finally closing in 2002 when the Frances H Burr Proton Therapy Center took over treatments at Massachusetts General Hospital.
As technology progressed and the benefits of proton beam therapy became clearer the first hospital based high energy proton facility exclusively for patients was introduced at Loma Linda in California in 1990 and since then interest from manufacturers and clinical oncologists has seen an exponential growth in proton beam therapy.
The UK has played a role in the development of proton beam therapy. A specialist eye service at Clatterbridge was actually the first hospital based proton beam therapy facility treating eyes with a low energy proton beam. The Clatterbridge ‘National Centre for Eye Therapy’ has treated over 2000 patients, more eye treatments than any other proton beam therapy institution.
Over 115,000 patients have been treated in 50 proton centres and the number of centres is rising rapidly. Although the USA has seen the most rapid rise in proton beam therapy, there are several proton centres in Europe. The last decade has seen proton facilities open in France, Germany, Italy, Poland, Russia and Sweden. The most recent centres to open look to use the latest delivery and imaging technology to treat a range of different indications. All major oncology centres worldwide are either planning a proton facility or delivering proton beam therapy.
The Christie is the first NHS high-energy proton beam therapy centre in the UK as part of a £250m programme for a national proton beam therapy service. A second proton beam therapy centre is also currently being built at University College London Hospitals NHS Foundation Trust. The new facility is due to open in 2020 with the proton beam therapy service ramping up in 2021.