I had a friend 10 years ago who had Non-Hodgkins Lymphoma and after a couple of rounds of targeted chemo, she had T-cells removed and grown, then her body was hit with a large dose of radiation, which finally killed the cancer and then the T-cells were replaced in the hopes of kick starting her immune system after the radiation destroyed it. It only partially worked and her immune system was extremely weak. She succumbed when she was hospitalized with the flu and a contracted a staph infection at the hospital. Her immune system wasn't strong enough to combat the infections.

I hope the medical advances have been significant in this area since she went through it and people are surviving.