A spheroid, like the name suggests, is a sphere of cancer that actually mimic the dynamics of real tumors down to the varying oxygen levels. And one of my colleagues went, ‘we could just grow spheroids,’” says David. “I remember when I first started in cancer research I lamented that the tumors weren’t perfect spheres because that would make the maths easier.

He works with biologists and clinicians to model oxygen levels in tumor spheroids.

Although his PhD is in a different area of physics (ultraviolet radiation), the mathematical modelling techniques he learned allow him to work out which areas of the tumor have high oxygen levels. Using chemotherapy and radiation therapy it’s possible to aim treatments at very specific sites-as long as you know where those sites are. “If we had a tumor and we knew that the corner of it had a lot of oxygen but the centre was seriously oxygen deficient, you could deliver three times the dose to get the same cell kill and obliterate the tumor since the centre is radioresistant,” explains David. Oxygen is a potent radiosensitizer meaning that areas with high oxygen are three times more sensitive to radiation than areas with low oxygen. How cancer cells react to radiation therapy is directly proportional to how much oxygen is in their region, making it important to understand where the areas of high and low oxygen are in the tumor. Because tumors grow in irregular, uncontrolled ways they have pockets of very low oxygen and very high oxygen. The human body has a system to ensure that all tissues that need oxygen have access to an adequate supply, however the same isn’t true when it comes to cancer tissues.

He wants to understand the importance of the oxygen microenvironment to improve cancer therapies, treatments, and outcomes. He is currently studying oxygen distribution in cancer as a Postdoctoral Research Fellow at Queen’s University Belfast and a Visiting Research Associate at Oxford University. I have been described as schizophrenic in my approach to work in that if I find something that interests me, I find the time to do something on it,” says David. “I have about 7 different research interests. He has written (and published) on everything from nuclear power to climate change to anti-vaxxers to musical acoustics.

David robert grimes good thinking