High-dose cytosine arabinoside and fractionated total-body irradiation: an improved preparative regimen for bone marrow transplantation of children with acute lymphoblastic leukemia in remission.

Twenty children with acute lymphoblastic leukemia in second (18 patients) or third (two patients) complete remission after bone marrow relapse received allogeneic bone marrow transplants from histocompatible sibling donors. The preparative regimen for marrow transplantation consisted of 12 doses of 3,000 mg/m2 cytosine arabinoside twice daily for six days followed by 1,200 cGy total-body irradiation (six doses of 200 cGy twice daily for three days). The preparative regimen was well tolerated, and all patients showed marrow engraftment promptly. Twelve patients are alive in complete remission 12+ to 79+ months posttransplant; eight patients are over 48 months posttransplant. Six patients died 1 to 9 months posttransplant of nonleukemic causes: (two each of graft-v-host disease, interstitial pneumonitis, and infection). Two patients developed recurrent leukemia at 15 and 30 months posttransplant. Both have died at 19 and 36 months posttransplant. Life table analysis reveals an actuarial survival and event-free survival rate of 58% and a marrow relapse rate of 17%. These results suggest that high-dose cytosine arabinoside and fractionated total-body irradiation is a relatively nontoxic and highly effective preparative regimen for allogeneic bone marrow transplantation for acute lymphoblastic leukemia that deserves further evaluation.