Fractionation of whole body irradiation before bone marrow transplantation for patients with leukaemia.

Thirty patients in various stages of acute leukaemia or chronic granulocytic leukaemia (CGL) were treated with cytotoxic drugs followed by whole body irradiation (TBI) administered in 200 cGy fractions twice daily to a total of 1000 or 1200 cGy. The immediate toxicity of fractionated TBI administered in this way was negligible and patients required only minor premedication and little treatment subsequently for complications attributable to TBI. Fourteen (47%) patients have died, ten of the 12 transplanted with active disease, and four of the 18 subjected to transplantation in remission of acute leukaemia or in chronic phase of CGL. Though the duration of follow-up is still short, no patient in the latter group (follow-up of survivors ranging from six to 146 weeks) has yet relapsed with any evidence of recurrent leukaemia. We conclude that this method of fractionating TBI reduced toxicity for the patient without necessarily reducing its antileukaemic effect.