Some patients also will be treated with chemotherapy and radiation as part of the transplant step that is needed to regenerate the bone marrow. The form of radiation you receive is called total body irradiation, or TBI. It is given to the entire body either before or after chemotherapy and prior to your transplant. The radiation treatment destroys the tumor cells and suppresses the function of the stem cells in preparation for the transplant. Radiation treatments are not painful and may be given in one single dose, or in seven or eight divided doses.