A blood stem cell or bone marrow transplant allows your child to have much higher doses of chemotherapy than usual. This can improve the chance of curing their cancer, but has more side effects. Very high doses of chemotherapy, sometimes with radiotherapy to the whole body (TBI), are given over a few days.

Bone marrow is a spongy material that is found inside some bones (particularly the pelvic bones).

Like a factory, bone marrow produces the cells that develop into the three different types of blood cells:

• red blood cells, which carry oxygen to all cells in the body
• white blood cells, which are essential for fighting infection
• platelets, which help the blood to clot and prevent bleeding.

Stem cells are blood cells at the earliest stage of development in the bone marrow. Within the bone marrow, stem cells develop into the different blood cells described above. When the cells are fully mature they are released into the bloodstream.

Very high doses of chemotherapy destroy the bone marrow. So, after high-dose chemotherapy, your child is given stem cells or bone marrow into their vein through a drip, central line, PICC line or implantable port. The stem cells make their way into your child’s bone marrow and start producing blood cells again.

There are two main types of transplant:

Using your child’s own stem cells or bone marrow – this is known as an autologous transplant or high-dose treatment and blood stem cell support.

Stem cells or bone marrow from a donor – this is known as an allogeneic transplant or an allograft. An allogeneic transplant is a complicated procedure. This intensive treatment is carried out in specialist hospitals. Recovery may take several months or more.

Please see our section on bone marrow and stem cell transplants for further information and how to deal with the side effects.