Surgeons in London have used lasers to diagnose abnormal tissue during an operation to remove a brain tumour for the first time in Europe.
The non-invasive technique measures light reflected off tissue to determine whether it is cancerous or healthy.
The patient, Reuben Hill, 22, is making a good recovery after the operation at Charing Cross Hospital.
It is hoped the technique could make this kind of delicate surgery faster and more accurate.
It has only been tired in Montreal, Canada, before now.
Mr Hill, who is from Devon and studying for a PhD in physics at Imperial College London, works with the same laser technology as used in his operation.
Before surgery, he told me: “My inner scientist is fascinated by what they are going to do.
“Understanding the physics involved definitely makes it less frightening.”