The use of fractionated radiotherapy as preparation for allogeneic bone marrow transplantation

Fractionated TBI has the advantage of reducing normal tissue damage when compared to single-dose TBI. If pulmonary damage is reduced through the use of fractionated TBI, a decrease in the incidence and severity of IP could result. This reduction in incidence and severity of IP has been observed in our series of patients. In addition, the decrease in lung toxicity has not been at the expense of decreased effectiveness of the regimen, either on engraftment, clearance of leukemia, or recurrence of leukemia. We are aware that our series of patients is small and the length of follow-up limited. However, our results suggest an advantage of fractionated TBI as compared to single-dose TBI as part of the preparatory regimen for BMT. Both TBI regimens are more toxic than Cy alone, but the reduced incidence of recurrent leukemia and the increase in long-term survival makes fractionated TBI an important addition to Cy in the preparation of patients for BMT. Continued study of fractionated TBI sees warranted.