Side effects of TBI must be considered in accompany with other elements of conditioning (chemotherapy) and the type of stem cell donor. For an allogeneic stem cell transplant and a mini-allo transplant, toxicity is more significant and more complex, especially due to graft versus host complications.
The most significant acute side effects:
Nausea and vomiting
Affect most patients, also after the first fraction. Antiemetic prophylaxis before the first fraction, preferably the evening before, is recommended.
Affects most patients and can be serious. Opiates may be necessary for pain treatment. Diarrhea may be a consequence of radiation-induced intestinal mucosa changes.
Hair and nail growth
Radiation therapy together with chemotherapy will cause reversible alopecia. Nail growth will stop and new nails may grow in replacement.
Fall of white blood cells will increase the risk of infections necessitating isolation of the patient during the aplasia period. Together with chemotherapy and immunosuppressive treatment, TBI may cause serious infections. Fall in platelets may lead to bleeding and require transfusions. Fall in red blood cells will cause anemia-related symptoms and require transfusions.
The most significant long-term side effects:
For certain regimens of TBI at Oslo University Hospital, dosing to the lungs is relatively low, but together with chemotherapy, injections and GVH, lung toxicity may occur.
Both women/girls and men/boys, the risk for sterility is considered very high with TBI with a total dose of 13 Gy, but this is not obligate for all patients. The risk depends most likely on multiple circumstances such as age, sex, total dose, and collective amount of chemotherapy.
Despite low doses, endocrine function should be monitored after TBI especially in children and adolescents.
Doses to the bone are low, but together with endocrine disturbances, growth disturbances may occur in children and adolescents.
The risk for a new malignant disease increases partly due to chemotherapy and radiation therapy, and partly due to necessary immunosuppressive treatment for allogeneic transplantations.