This is the first time that the edge of growing tumours can be mapped and the proteins, caused by the body's inflammatory response, can pinpoint the likely areas of the tumour spreading.
By attaching a specially developed dye (VCAM-1) to the proteins produced in the blood vessels, MRI scans can pick up the tumour's edges.
Previously, such scans often miss intact blood vessels and therefore can present an incomplete picture of the extent of a brain tumour.
Due to the fact that the proteins are produced inside the blood vessels, they are accessible via the bloodstream.
Professor Nicola Sibson, study author and Cancer Research UK scientist at The University of Oxford, said: “If we can't map the edge of the tumour, surgery and radiotherapy often fail to remove aggressive tumour cells – and the brain tumour can grow back.
“This research shows that we can improve imaging of brain tumours, which could help both surgeons and radiotherapists with more effective treatment."
The hope is that these findings from the trials could lead to clinical trials in the near future.
The study is being presented at the National Cancer Research Institute (NCRI) Cancer Conference in Liverpool today and was funded by Cancer Research UK and the Medical Research Council.