My niece did this treatment. It is experimental in the USA. They did it and she reacted badly and they have to induce a coma and then did radiation. She seemed to be doing well after they found cancer in other places in her body at which point she decided to stop treatment. She died a week later. *sigh*
I believe this treatment spread the cancer and killed her faster.
I don't know enough about it to really say where it went wrong but I think perhaps this might be best for someone in the very very early stages of cancer.
It is still very much experimental.