Definition:
stem cell transplant (stem sel TRANZ-plant)
A method of replacing immature blood-forming cells in the bone marrow that have been destroyed by drugs, radiation, or disease. Stem cells are injected into the patient and make healthy blood cells. A stem cell transplant may be autologous (using a patient’s own stem cells that were saved before treatment), allogeneic (using stem cells donated by someone who is not an identical twin), or syngeneic (using stem cells donated by an identical twin).
Enlarge Drawing of stem cells being removed from a patient or donor. Blood is collected from a vein in the arm and flows through a machine that removes the stem cells; the remaining blood is returned to a vein in the other arm.

Stem cell transplant (Step 1). Blood is taken from a vein in the arm of the donor. The patient or another person may be the donor. The blood flows through a machine that removes the stem cells. Then the blood is returned to the donor through a vein in the other arm.

Enlarge Drawing of a health care provider giving a patient treatment to kill blood-forming cells. Chemotherapy is given to the patient through a catheter in the chest.

Stem cell transplant (Step 2). The patient receives chemotherapy to kill blood-forming cells. The patient may receive radiation therapy (not shown).

Enlarge Drawing of stem cells being given to the patient through a catheter in the chest.

Stem cell transplant (Step 3). The patient receives stem cells through a catheter placed into a blood vessel in the chest.