Oxygen Modelling and Tumour Hypoxia

The availability of oxygen in a tumour has a large effect on patient prognosis; Oxygen is a potent radio-sensitizer and greatly magnifies cell-kill. Unlike healthy tissue, chaotic and poorly perfused vasculature is a hallmark of tumours and as a result regions of hypoxia (low oxygen) are common. These regions are less responsive to radiotherapy, but if oxygen distribution can be well estimated, then in theory one could selectively boost dose to regions of low oxygen without over-dosing the surrounding tissue. This concept is known as dose-painting, but it's complicated by the fact that it is very difficult to measure oxygen in situ. Much of my current research focuses on modelling underlying oxygen distribution in both vascular and avascular tumours to better understand oxygen distribution and the factors that influence it. I also do some modelling of tumour growth, and work closely with biologists here at University of Oxford to validate these models.

Example of a Spheroid
A DLD-1 tumour spheroid - Oxygen can diffuse only a certain distance through the ball of tumour cells before being entirely consumed by the respiring cells, resulting in an anoxic core. Some of our research indicates information about the rate of oxygen consumption can be estimated with when the radius of the anoxic core and over-all spheroid radius are known. This also yield information about the evolution of these growths in time

Ultraviolet radiation dose modelling

My PhD research focused on Ultraviolet phototherapy, a treatment for common skin conditions such as psoriasis. Whilst the treatment is very effective, over-exposure can be biologically detrimental and unlike highly-ionizing treatments, dose is often not well regulated. My research here focuses the development of accurate and powerful dosimetric models, which can predict the exact amount of irradiance on a patient's skin at any orientation. I also do some modelling of how cabin design impacts dose received at the patient epidermis.

UVR
Modelling Ultraviolet Radiation is complicated as dose is deposited at the skin surface, so orientation matters. There is also complex interplay of UVR reflection and source placement which heavily influences the quantity and homogeneity of the dose. This figure shows the dose shape from a bank of ten ultraviolet emitters with surrounding reflectors.

Other Interests

I have a interest in applying a physics approach to a variety of topics, and have published research on things as diverse as the physics of guitar strings to why homeopathy cannot work from a physical sciences perspective.
Guitar
Measuring bend angle on a guitar fretboard and the subsequent effect on pitch. I still feel guilty about hammering nails into a fretboard, but it was for science..

Selected Publications

About Me

Dave

I really should select a better image but that would require time and energy, which means there's a Heisenberg joke in there somewhere (the real-life Physicist, not the fictional Drug Lord!). Please note this site is still in beta and will likely change in upcoming days! Any opinions expressed are my own and not those of the University unless they have a particularly cool opinion, in which case I'll shamelessly pilfer it and pass it off as my own.