No paparazzi here - non-invasive pictures of cancer.
By Dr Martin Christlieb of the Gray Cancer Institute, Department of Radiation Oncology and Biology, University of Oxford.A diagnosis of cancer must be followed by an assessment of how severe the disease is and which treatments it might respond to. Cancer is as individual as the people who suffer it, but just as people can be grouped together
by age or nationality cancers can be grouped by important characteristics. One such factor that can mean the difference between life and death is the presence or absence of oxygen in the tumour. During radiotherapy, beams of high energy radiation cause damage to tumour cells. The cells can repair some of the raw damage, but not after oxygen has reacted with the damaged sites. Some tumours are high in oxygen and treatment with radiotherapy is often successful: other tumours have very low oxygen levels and the outcome is often poor and an alternative treatment would be better. In order to decide the best treatment the doctor would need to know the oxygen status of their patient's disease. Traditionally, the levels of oxygen could only be determined following surgery or at least biopsy. Research at the CRUK-MRC Radiation Oncology Unit at the Churchill Hospital is hoping to develop a less intrusive way of finding the oxygen levels in a tumour. Our method replies on a new scanning technique called Positron Emission Tomography (PET). PET was recently introduced in the NHS to help locate tumours using their increased consumption of sugar. PET uses tiny quantities of radio-active materials to form an image of processes taking place within the body. Because it is non-invasive, it requires no injury to the patient and because it is extra-ordinarily sensitive the radiation dose to the patient is tiny. PET is normally combined with X-ray techniques. X-ray giving very detailed images of anatomy and PET filling in the functional information so valuable to determining what's going on. In this case we are interested in finding out which tissues are short of oxygen and where they are located; this information can be used to help plan which course of therapy is most appropriate to the patient. Many people have seen the Cancer Research UK shops in towns and cities. The blue shop sign with its triangle of dots representing one cancer cell amongst many normal cells. The money raised in these shops is the primary source of funding to our project and many others like it that aim to give medics more information about cancer and allow academics to develop new ways of treating it.
The Science Matters page is compiled by Science Oxford, cultural centre for science in St Clements.
www.scienceoxford.com