Currently, any form of radiotherapy results in unwanted but unavoidable deposition of radiation to healthy tissue around the targeted tumour. Studies have shown that treatment using ultra-high dose rate (UHDR) radiation could significantly spare healthy tissue while also being at least as effective as treatments at conventional dose rates in controlling the tumour – this is known as “the Flash effect”.
Hannah Cook, a higher scientist at NPL, said: “Proton therapy dosimetry and audit development is very interesting and rewarding research. The aim of our work is to provide confidence to clinical centres offering proton therapy treatment within the UK and worldwide, with the hope to further improve cancer patient outcome.”
NPL science area leader Russell Thomas told the PA news agency proton beam therapy has been around since the 1940s, but only around 300,000 patients around the world have been treated with it. In comparison, some 160,000 patients a year are treated with conventional photon therapy in the UK, he added.
Mr Thomas explained that in the past one of the blocks to photon beam therapy has been cost. A proton beam machine can cost in the region of £225 million, compared to just a couple of million pounds for a conventional machine.
There are currently only two proton beam therapy centres in the UK – at The Christie NHS Foundation Trust in Manchester, or University College London Hospitals NHS Foundation Trust. Mr Thomas told PA news agency that he hoped that one day there would be enough centres in the UK to treat the numbers of patients who might benefit.
He added: “I think with proton provision in the UK now we’re probably treating slightly less than 2% of the radiotherapy population that would benefit – 5% to 20% is the estimate. So I’d like us to at least get to 5% of treatments.
“I think what I’d also like to see is investment for you, and ways of looking at other particles and other ion therapy. Different types of radiation and beam and a radiation treatment will have different radiobiological effectiveness.
“It would be great if we could have some funding in the UK to explore these at the radiobiological level, at the pre-clinical level so that we can work out right, well this would be good if we could follow this type of particle and we can start building this type of machine for treating patients.”