Radiation therapy is often part of the transplant preparative regimen — treatment used to prepare a patient for bone marrow transplant. Total body irradiation (TBI) gives a dose of radiation to the whole body. TBI can destroy cancer cells throughout the body. It also destroys the immune system so that it will not attack the donor's cells during the transplant.
TBI can reach cancer cells within scar tissue or other areas of the body that chemotherapy may not reach. However, the dose of radiation must be low enough that the body's healthy cells can recover. For this reason, TBI alone cannot be used to destroy large numbers of cancer cells. Instead, the transplant preparative regimen uses TBI along with high-dose chemotherapy. (Some preparative regimens use only chemotherapy and do not include TBI.)
The Advantage to Patients
TBI is administered in order to eliminate remaining cancer cells. It is also done to suppress the immune system. This is necessary to help lessen the risk of rejection of transplanted tissue in bone marrow transplant patients.
Type of Cancer treated with Total Body Irradiation
Currently, TBI is being used at Penn to treat: