PRaVDA (Proton Radiotherapy Verification and Dosimetry Applications) - Integrated computed tomography and dosimetry instrument for proton therapy (360G-Wellcome-098285_Z_12_Z)

Proton therapy (PT) enables the lowering of the integrated radiation dose to the patient (compared to x-rays) due to the finite range of protons and it permits more accurate targeting of this dose. The basis for this is the proton's Bragg peak, which increases the dose deposited at the tumour site. However, PT is less tolerant than x-ray treatment to uncertainties in both treatment planning and treatment delivery. There are 37 operational PT centres worldwide (with a further 50 in planning/construction stage) and the UK Government through the Department of Health has agreed to the construction of 2-3 centres in the UK. PT is valuable in pediatrics and where there are avoidance problems where tumours are intimately associated with vital structures. There is strong support in the USA for the use of PT in the treatment of prostate cancer the most common non-skin cancer, affecting 1 in 6 men. Some proponents of PT conservatively suggest that it is a superior treatment for some 30% of all cancers. The outstanding questions relate to the need for more long-term randomised trials and economic dimension of the higher cost of PT facilities over x-ray ones. Facility build costs will reduce with the advent of compact sources and integration of image-guided radiotherapy systems such as PRaVDA which promote more effective and more efficient treatments. PRaVDA will be the world's first silicon-based detector system that will allow in-situ monitoring of the incident dose, in terms fluence, energy and distribution both prior and during treatment and provide quality images during treatment as well as realise interactive proton computerised tomography (CT) the ultimate aspiration for radiotherapy. The three-year project brings together the UK's leading detector and instrumentation scientists together with medical physicists and oncologists in an adventurous project in close partnership with industry and other stakeholders. We have the use of the UK's only research proton facility for extensive testing, and guaranteed access to other cyclotrons at key PT treatment centres; together with unique skills in designing novel detectors that lie at the heart of PRaVDA.