Stem cell transplants, also known as bone marrow transplants, enable a child to have higher doses of chemotherapy drugs.

Before a stem cell transplant, stem cells are collected from the bone marrow or bloodstream. Very high doses of chemotherapy follow, which destroy cancer cells and, inadvertently, stem cells in the bone marrow.

After chemotherapy, the stem cells collected earlier are given through a drip making their way into the bone marrow where they begin producing mature blood cells again.

There are two main types of transplant:

• Autologous: uses your child’s own stem cells, which are collected some time before the high-dose treatment and stored until needed.
• Allogeneic: uses stem cells from a donor. This is a more complicated procedure than an autologous and is only carried out in specialist hospitals. Recovery may take several months or longer.