A man's brain tumour has shrunk by half in a matter of weeks thanks to a new radioactive therapy.
Paul Read, 62, from Luton, was the first patient to take part in a trial aimed at treating glioblastoma, a type of cancer that kills most patients within 18 months.
He described the treatment, at University College London Hospitals NHS Foundation Trust (UCLH), as "a lifeline".
The doctor who designed the trial said the results were "remarkable for somebody whose tumour is so aggressive".
The therapy involves injecting low levels of radioactivity directly into the tumour to kill off cancer cells.
Surgeons first removed as much tumour as possible before implanting a small medical device, called an Ommaya reservoir, under the scalp.
The drug ATT001, which is given weekly for four to six weeks, is potent over short distances, causing lethal damage to tumour cells while sparing healthy tissue.
Mr Read first noticed a severe headache last December and, two weeks later, his face dropped on one side.
He had surgery shortly after his diagnosis to remove as much of the tumour as possible, followed by radiotherapy and chemotherapy.
In July, doctors found the tumour was growing again and he was offered a place on the new CITADEL-123 trial at UCLH.
"I was fully expecting the tumour to return due to its aggressive nature. I know the outcome isn't great and I was happy to explore anything else," he said.
"I'm not frightened by any of this. We are all dealt a hand of cards and you don't know which ones you are going to get.
"It will be wonderful if this treatment helps me and if it doesn't, it doesn't... it may benefit someone else down the line."
'Really quite remarkable'
The trial was designed by UCLH consultant medical oncologist and chief investigator Dr Paul Mulholland.
He said: "Because it's targeted directly to the tumour cells, it's very powerful at killing them.
"We've just gone through [Paul's] scan results with him and his end of treatment scan shows a reduction in the tumour, which is really quite remarkable for somebody whose tumour is so aggressive."
Dr Mulholland said, as it was the first human study, they had been cautious in their approach, but later hoped to increase the dose of radiation and number of patients.