It is widely acknowledged that current methods for treating cancer are far from ideal, often resulting in side-effects with both short and long-term impacts on patients’ health. A new collaborative research project called PRaVDA is working towards expanding the options available for cancer patients in order to revolutionise the future of cancer diagnosis and therapy.
Targeting cancer cells
330,000 people are diagnosed with cancer in the UK every year and around two-thirds of these will receive radiotherapy as part of their treatment. Whilst radiotherapy uses high energy x-rays to destroy cancerous cells, a new technology is looking to protons, positively charged particles, as an alternative solution to cancer treatment. But why?
Although radiotherapy successfully damages cancer cells it also affects healthy tissue that should not be exposed to radiation. Where cancer occurs near crucial organs e.g. spine, head and neck, as well as in young patients, the destruction of healthy cells can lead to side-effects such as paralysis and increased risk of secondary cancers later in life. The advantage of proton technology is therefore its ability to target cancerous cells only.
While x-rays slowly release energy as they travel through the body, damaging the DNA of many healthy cells before and after the tumour, proton therapy has the ability to focus on cancerous cells by peaking the energy released when they hit a tumour, a phenomenon known as the ‘Bragg peak’ (see below). Consequently little radiation is absorbed by the surrounding tissue, meaning healthy tissue remains healthy. However, “you’ve got to know exactly where those protons are going to lose their energy and you’ve got to know how the protons interact with the tumour” says Professor Nigel Allinson from the University of Lincoln. Queue the PRaVDA project.
The PRaVDA project, which is a consortium of researchers from both UK and South African universities and laboratories, is aiming to use protons to create a 3D image of cancerous cells within the body before and during treatment. By using protons to both image the patient’s body as well as to treat the cancer “this means more accurate treatment planning” says Dr Michela Esposito of the University of Lincoln. Using technology developed at CERN the team will assess the pathways taken by proton beams in order to accurately identify where protons should be targeted within patients. This will be “one of the most complex medical imaging instruments ever thought of” says Professor Nigel Allinson, Project Director and Principal Investigator. Ultimately this research should provide the final piece of the puzzle in the implementation of proton therapy for cancer treatment which has so far been constrained. Nigel Allinson added, “different scientific disciplines… can come together to provide the missing element for the full future exploitation of proton therapy for the better treatment of cancer”.
When will proton beam therapy be available?
Although proton therapy currently costs around 10x more than radiotherapy, the planned development of two new NHS Proton beam therapy centres by 2018 points to a clear future. In fact Allinson claims that “the bulk of radiotherapy will be done with protons in ten years’ time”. “If we’re successful and what we build is taken up by industry, [and] by the various national health services, we will have an instrument which I hope and believe will improve the quality of life for many cancer patients”.
This research was presented as a part of an exhibition showcased at the Royal Society’s Summer Science Exhibition held from 1-6 July. To find out more about the other exhibits shown, including how ants are helping to us to find new antibiotics and how we may soon be able to replace our own teeth, listen to this podcast from Quentin Cooper, presenter of Radio 4’s Material World as he explores the exhibition.