Work by Cockcroft Institute at eye tumour centre will revolutionise treatment
“We get the difficult eye tumours here”, says Dr Andrzej Kacperek, Head of Cyclotron at the The Clatterbridge Cancer Centre NHS Foundation Trust, one of only dozen centres in the world to offer ocular Proton Beam Therapy. A partnership with the Cockcroft Institute promises to optimise control of the beam, significantly shortening treatment time and creating a leading position for theUKin this emerging field of technology.
Prof. Carsten Welsch, Associate Director, of the Cockcroft Institute explains, “Unlike, most types of radiation used in medicine such as X-rays or electrons, proton beams can be directed to target just the cancer tumour minimising damage to healthy tissue and leaving zero dose beyond the tumour; this is particularly important in the eye. However the techniques used for controlling the beam rely on the skill of the operator and sometimes rather basic instrumentation. We are working to automate this process and lower the cost per patient of this treatment.”
Protons are positively charged particles, created when a hydrogen atom loses its electron. They are formed in an ion source and then accelerated, for example, in a cyclotron - a compact circular accelerator.
Dr Kacperek explains that when the Douglas Cyclotron commenced proton therapy 24 years ago it was one of the few in the world to offer this type of ocular therapy. Thus the team here had to make much of its own instrumention which was challenging but successful. In fact some of this equipment has been used at other newer centres.
“Protons are heavy charged particles that penetrate tissue for a short precise distance and deposit most of their energy at the end of the beam so the target cancer is destroyed but the healthy tissue is spared. This remarkable phenomenon is called the ‘BraggPeak’.
“The degree of precision is unique to proton beams. We can control how deep the beam goes so it can be used to treat a tumour on the iris or one at the back of the eye. Also as protons scatter very little the beam has sharp edges, which makes it possible to follow the outline of the tumour and protect the optic nerve. We can deliver a consistent dose by modulating the Bragg peak across the tumour depth.”
Dr Kacperek has a ‘Bragg Peak Wheel’ (made from Perspex), to help measure the modulation and proton range required. A brass collimator is made at the workshop for each patient that tailors the cross-section of the beam to the exact shape of the tumour. He is delighted by the support he is getting from researcher Tomasz Cybulski of the Cockcroft Institute to automate these procedures, made possible via the European Commission funded DITANET Project.
Tomasz Cybulski says the beam intensity determines the extent of the damage to the malicious cancer cells so measuring the current is vital to determining the dose given to the patient.
“We are looking at non-invasive ways to measure the beam to provide quality assurance. For this we are looking at the beam halo, which is created by natural scattering of protons when the beam passes through the air to reach the patient’s eye. The mechanical design for this detector has been finalised and we are now working on the electronics."
“The beauty of working with the team at Clatterbridge is the expertise they have in running the Cyclotron. This knowledge has been invaluable.”
Dr Kacperek says, “The treatment takes only 30 seconds but the session takes 35 minutes as you need to manually calibrate the equipment as well as positioning the patient. If we can reduce this time we could see more patients in peak periods or reduce the runtime for the Cyclotron in slack times which would be a massive cost-saving.”
At present ten per cent of patients come from overseas, so there is also potential to generate increased revenue to off-set fixed costs. Indeed a new private clinic is being opened on the same site from which profits will be used to enhance NHS services.
Improved instrumentation for proton therapy is one of the many outcomes of the DITANET Project, coordinated by theUniversityofLiverpoolfrom the Cockcroft Institute, which aims to develop beam instrumentation.
Although public knowledge of accelerator physics has increased in recent years with the work at CERN on the Hadron Collider, it is not yet a ‘classic’ area of physics and the techniques for controlling the power of the beam are still in their infancy. The DITANET Project aims to address this gap and fast track development of vital tools by creating a community of researchers across industry and academia.
Before coming to the Cockcroft Institute, Prof. Welsch's research career led him toJapan, theUSA,GermanyandSwitzerland. During this time he saw clearly the need for greater collaboration, in particular with industry.
“Detailed diagnostics of charged particle beams is still an emerging area with many opportunities for ground-breaking research and a growing range of industrial and medical applications. There is a strong need for many more researchers trained in this interdisciplinary area. To define an ideal and comprehensive training program, we have got business, universities and research centres involved at an early stage of the DITANET project to define their individual requirements and provide placements for our researchers.”
Instrumentation that will improve proton beam therapy has huge commercial potential, Analysts CSIntell estimates that in 2011 the global proton therapy device market reached US$350 million and predicts it to be growing at 9 per cent.
The NHS is investing £250 million in two new high-energy proton beam therapy units at Christie NHS Foundation Trust inManchester,UniversityCollegeLondonHospitaland University Hospitals Birmingham NHS Foundation Trust.
The work developed at Cockcroft by the DITANET project has the potential to reduce running costs and increase patient throughput at these new facilities.
About DITANET
The Marie Curie Initial Training Network DITANET - "DIagnostic Techniques for particle Accelerators - a European NETwork" has been coordinated by theUniversityofLiverpoolsince November 1st 2008. With a budget of up to 4.16 M€ it is the largest-ever EU funded education action for early stage and experienced researchers in beam instrumentation for accelerators. The network was initiated and is coordinated by Prof. Carsten P. Welsch who joined the University in November 2008.
The DITANET project partners continue to organise international training events for the wider beam diagnostics community and actively promote research collaboration in beam instrumentation.
About the Cockcroft Institute
The Cockcroft Institute is an international centre for accelerator science and technology in theUK. It is a joint venture between the Universities of Lancaster, Liverpool andManchesterand the Science and Technology Facilities Council (STFC at the Daresbury and Rutherford Appleton Laboratories). The Institute is located in a purpose-built building on the Sci-TechCampus adjacent to the Daresbury Laboratory and the Daresbury Innovation Centre, and has established satellite centres in each of the participating universities.
The Clatterbridge Cancer Centre
The Clatterbridge Cancer Centre is one of the largest networked cancer centres in theUK. From nine operating sites, across Merseyside andCheshiretreating over 27,000 patients a year, offering pioneering chemotherapy, radiotherapy and proton therapy treatments.
The Physics Department at The Clatterbridge Cancer Centre supports the clinical work of the Centre, and helps to develop and introduce new techniques and facilities. The department consists of around 50 members of staff, including registered and trainee Clinical Scientists, Clinical Technologists and Researchers. It provides expertise in radiotherapy, as well as supporting imaging modalities such as X-rays, CT, MRI and nuclear medicine. The onsite Douglas Cyclotron provides theUK’s only proton-therapy facility for ocular tumours. Their research group includes postdoctoral scientists and PhD students.
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