Nathan Crawford is the first in the UK to have the procedure after fears chemotherapy could make him infertile.
A nine-year-old boy with a brain tumour has had testicular tissue frozen in the hope he can one day still have children.
Nathan Crawford is the first in the UK to have the procedure after fears his radiotherapy and chemotherapy treatment could make him infertile.
Surgeons at John Radcliffe Hospital in Oxford removed a wedge of tissue containing sperm stem cells and hope to re-implant it later in life.
Dr Shiela Lane said the treatment - which took less than 30 minutes - had been shown to work in animals.
"During the procedure, you take what looks like an orange segment out to divide into small parts, which then get frozen.
"You are storing the tissue which contains the stem cells.
"What happens when you put this tissue back is that it generates its own blood supply and starts producing normal hormones, which restores fertility."
The procedure is similar to freezing ovarian tissue, which has already helped women give birth.
Nathan's family, from Bude in Cornwall, said they noticed something was wrong in January when he started having headaches and blurred vision.
They have also explained to the nine-year-old how the procedure could help him when he grows up.
"Nathan loves children and so we told him this would increase the chances he can have his own children," said stepfather Jonathan Alison.
He said the family "couldn't be prouder" and that Nathan had taken the tumour treatment and keyhole procedure "all in his stride".
"He's coped really well and hasn't suffered too much from side-effects, just some jaw ache and a bit of sickness," said Mr Alison.
He added: "Once he'd been up to Oxford to have the testicular tissue removed, he was back home in Cornwall within 48 hours eating fish and chips with us."
Nathan's tumour is called a glioma and is so close to his brain that operating on it could cause serious damage.
He has already had radiotherapy and is now on a second round of chemotherapy.
Dr Lane said Nathan could still have a bright future: "These tumours can possibly be cured with intensive chemotherapy. Patients can have a long and happy life without any problems."
Kate Lee, Chief Executive of CLIC Sargent, the children and young people’s cancer support charity, said: "Although at this early stage it is difficult to predict how successful this new technique will be, it is certainly a fantastic opportunity for the young boy and family involved, and a positive step forward."