Total body irradiation (TBI) is a form of radiotherapy used primarily as part of the preparative regimen for haematopoietic stem cell (or bone marrow) transplantation.
Doses of total body irradiation used in bone marrow transplantation typically range from 10 to >12 Gy.
For reference, an unfractionated (i.e. single exposure) dose of 4.5 Gy is fatal in 50% of exposed individuals without aggressive medical care.
[citation needed] In addition to its use in bone marrow transplantation, total body irradiation has been explored as a treatment modality for high-risk Ewing sarcoma.
Total body irradiation results in infertility in most cases, with recovery of gonadal function occurring in 10−14% of females.