from stage 4 high-
The high intensity chemotherapy that Charlie received during his treatment will almost certainly have rendered him infertile.
So he underwent an experimental treatment called Testicular Tissue Cryopreservation (TTCP) in order to try and preserve his fertility, so if he wants to father a child in the future, he will have the best possible chance of doing so.
You can read more about this treatment in this information booklet. The Future Fertility Trust is leading this groundbreaking work in the UK. It is also available down under at the Royal Children’s Hospital in Melbourne, which is where some of Charlie’s testicular tissue is now stored ready to be used one day!