Brain Cancer is a particularly serious disease, usually returning within a year of surgery despite the use of radical treatment with radiotherapy and chemotherapy. This project aims to extend the lives of brain cancer patients by using more sophisticated imaging techniques to improve treatment, and is being conducted in collaboration with the Royal Brisbane and Women's Hospital and the University of Queensland.
In addition to Magnetic Resonance (MR) Images taken of patients, dynamic Positron Emission Tomography (PET) images are also taken. PET images make it possible to visualise the pattern with which cells take up certain chemical markers and because of this their use is a good way to detect tumourous tissue. MRI scans compliment the PET data as they show where cancer is very advanced, i.e. sufficiently so to cause the walls of blood vessels to leak. MR scans give high resolution anatomical information and allows the imaging of subtle differences in the chemical make up of different tissues in the body.
To use these images together they are first aligned and fused, as shown in the image below.
In this video sequence of a dynamic PET scan a tracer called FDOPA is being taken up by various structures in the brain over a 75 minute period. Initially the tracer floods through the blood vessels before flowing into the brain tissue and the tumour. The tumour takes up FDOPA more rapidly, because the cancer cells use the FDOPA as a raw material to cerate more cells and divide, which they do far more frequently than healthy cells. The visible parts of the tracer are eventually excreted by the body. Towards the end of the scan the striata of the brain are seen, as these take up and excrete FDOPA more slowly than other tissues. This is normal.
The combined information should help surgeons to better plan which areas to remove. Unlike in other cancers the risk of the cancer recurring is high, because surgeons need to err on the side of removing too little tissue, for fear of damaging working brain tissue. Radio- and chemo-therapy planning suffers from similar difficulties. One way in which the project is working to improve this is to extract and visualise the most aggressive parts of the tumour.
This work should allow us to motivate for greater amounts of therapy to being given to areas that are usually missed. This will lessen the risk to the rest of the brain and more effectively suppress the brain cancer.
Last Updated on Wednesday, 05 October 2011 12:40