Total Body Irradiation (TBI) is a radiotherapy technique used to ablate the bone marrow and immune system prior to bone marrow transplantation or peripheral blood stem cell transplantation. It may be used as part of high-dose treatment of some leukaemias and lymphomas. The aim of this type of ablative therapy is to prevent rejection of the transplanted cells.

During TBI the whole body is irradiated to approximately 9 Gy, a dose which, though modest by normal radiotherapy standards (when restricted to a small portion of the body, usually the tumor site,) would be lethal when absorbed by the entire body, were rescue with the transplant not to follow directly.

Transplantation medicine | Radiobiology