Around 4,300 people are diagnosed with a low-grade brain tumour each year in the UK – which tend to be slow-growing, have well-defined edges and are less likely to return or spread to other parts of the brain.
Standard treatment includes surgery to debulk or remove the tumour, or for some low-grade tumours that are unlikely to spread, a ‘watch and wait’ approach may be used where no treatment is given unless symptoms develop or regular scans identify changes to the tumour.
Current MRI methods take a single cross-section of the brain, essentially a 2D ‘slice’ of the tumour. But new findings by scientists at the Erasmus University in Rotterdam suggest that visualising the whole tumour may be critical to identifying key changes and where patients may need more active treatment.
In a study of 18 patients, part-funded by The Brain Tumour Charity, scientists found that using chemical exchange saturation transfer (CEST) MRI to scan the whole tumour identified areas of low-grade brain tumours that look like high-grade cancers – which would be missed on traditional scans.
The Charity’s Research Communications Manager describes the new technique like a hunt for an apple seed. She says “If you slice through an apple at any random point you’ll be able to tell that it’s an apple. But if you make a series of thin, parallel slices you’ll be able to find all the seeds. In this case the apple represents the low grade tumour, and seeds are areas of tumour that are higher in protein and may be becoming more active.”
The researchers, led by Professor Marion Smits and Dr Juan Hernandez-Tamames, found that CEST MRI was sensitive to changes in glioma tissue compared to healthy brain tissues. The image above was taken from the paper published in the scientific journal Magnetic Resonance Materials in Physics, Biology and Medicine. The image highlights areas the team think are more active, and could be starting to grow faster.
Their next step is to analyse biopsies taken from brain tumours that are more, or less, aggressive and compare them to the CEST MRI ‘predictions’ of activity.
Dr Esther Warnert, the lead author, told us “This technique shows promise to be used to accurately determine where the tumour is most aggressive. In the long term it could help a surgeon to decide where to take a biopsy for the accurate diagnosis”
While further validation is required, it is hoped the technique could soon provide valuable information in the diagnosis and treatment of low-grade brain tumours, as it does in high-grade cancers.
You can read more about the research we're funding in Dr Smit's lab here.