A boy with a brain tumour has become the first in the UK to have testicular tissue frozen with the hope he can have children later in life.
Nine-year-old Nathan Crawford has undergone treatment to shrink his inoperable tumour but it could render him infertile.
In a ground-breaking procedure, surgeons at the John Radcliffe Hospital in Oxford have removed a wedge of testicular tissue and frozen it, and will aim to one day re-implant it into Nathan.
If the procedure is successful, Nathan will have a good chance of becoming a father.
Nathan, from Bude in Cornwall, has a type of tumour called a glioma, which develops from the glial cells that support the nerve cells of the brain.
Nathan has undergone a course of radiotherapy and is currently having a second round of chemotherapy with the aim of shrinking the tumour.
Stepfather Jonathan Alison, 34, said the family first noticed something was wrong with science-mad Nathan in late January.
Mr Alison said he and Nathan's mother Donna Hunt, 31, have explained the tumour to Nathan and how the procedure to store testicular tissue might help him in later life.
Dr Sheila Lane, a consultant paediatric oncologist who is clinical lead for tissue cryopreservation at the John Radcliffe, said the new technique had been shown to work in animal models.
It is similar to ovarian tissue freezing, which has already produced live births for women undergoing the procedure.
She said Nathan's tumour was inoperable and chemotherapy and radiotherapy are the only options for shrinking it.
But she added: "These tumours can possibly be cured with intensive chemotherapy. Patients can have a long and happy life without any problems."