Optimising dermatological photodynamic therapy effectiveness using a novel radiative transfer model
This project is one of a number which are funded within the Carlota Palmer PhD programme. This four-year programme, run under the auspices of the Centre for Biomedical Modelling and Analysis, will commence in September 2016. The studentships will provide funding for a stipend (currently £16,165 per annum), research costs and UK/EU tuition fees for four years. Further details can be found here: http://www.exeter.ac.uk/bma/phd/
Location: Streatham Campus, University of Exeter, EX4 4QJ
Academic Supervisors: Professor Tim Harries, Physics and Astronomy, University of Exeter, Dr Alison Curnow, Medical School, University of Exeter, Dr Clare Thorn, Medical School, University of Exeter
Every day the human skin is exposed to ultraviolet radiation from the sun and as a result, non-‐ melanoma skin cancer (NMSC) is the most common form of cancer worldwide. Prevalence is increasing, with over 80,000 new cases reported in England in 2008 and NHS skin cancer costs predicted to approach £180M by 2020. Efficacious, cost-‐effective and cosmetically acceptable NMSC treatments are therefore essential.
Photodynamic therapy (PDT) uses light to activate a pre-‐administered drug to kill skin cancers without harming healthy cells, so healing occurs without scarring. PDT is particularly effective against superficial NMSC, however ~50% of lesions are too thick to be treated with the standard protocol. Optimising PDT treatment parameters to increase effectiveness is therefore vital for public health and would save considerable NHS resources.
PDT efficacy strongly depends on the amount of light penetrating the skin, a quantity that is difficult to determine in situ. However the path of photons through the skin, and hence the dosage, can be effectively modelled on a computer. We have adapted an astrophysics Monte Carlo code to model how light propagates through the skin. The code provides us with a novel ‘virtual’ PDT laboratory, where the intensity, distribution and colour of light delivered to the skin can be varied and the photon dose at any depth quickly determined. Key to this code is its ability to model the heterogeneous nature of the skin and underlying tissue.
This research programme will evaluate the biological modelling accuracy of the code using a preparation of pig skin. Non-‐invasive spectroscopic measures of light transmission, drug fluorescence and tissue oxygenation will be monitored simultaneously in real-‐time and the data will be used to optimise the numerical model.
This validated ‘virtual’ PDT model will then be applied to current protocols used in PDT. The aim will be to determine how the numerical simulations can be used to optimise PDT photon dosage to treat at greater depths within the skin than currently feasible. Variables such as the wavelength and geometry of the light source and novel clinically relevant PDT drugs will be considered.
This unique interdisciplinary and experienced supervisory team combines world-‐leading expertise in numerical modelling/radiation transport, photodynamic therapy and non-‐invasive monitoring of skin microcirculation. The successful student will therefore gain theoretical, experimental and translational clinical research expertise in a significant health problem of our ageing population.
Applicants should have obtained, or be about to obtain, a First or Upper Second Class UK Honours degree, or the equivalent qualifications gained outside the UK, in an appropriate area of science or technology. Applicants with a Lower Second Class degree will be considered if they also have Master’s degree or have significant relevant non-academic experience. If English is not your first language you will need to have achieved at least 6.5 in IELTS (and no less than 6.0 in any section) by the start of the project (alternative tests may be acceptable, see http://www.exeter.ac.uk/postgraduate/apply/english/).
£16,165 per annum plus UK/EU fees for eligible students (2015-16 rates)