Between October 1988 and December 1992, 167 patients with leukemia receiving marrow transplants from HLA-identical donors and conditioned with cyclophosphamide (120 mg/kg) were randomized to additional treatment with either busulfan (16 mg/kg, n = 88) or total body irradiation (TBI; n = 79). The busulfan-treated patients had an increased cumulative incidence of veno-occlusive disease of the liver, ie, 12% compared with 1% in the TBI group (P = .009). Furthermore, hemorrhagic cystitis occurred in 24% of the busulfan patients versus 8% in the TBI patients (P = .003). In patients with advanced disease beyond first remission or first chronic phase, transplantation-related mortality was 62% among the busulfan-treated patients compared with 12% among the TBI recipients (P = .002). These differences between the two groups were statistically significant in multivariate analysis. Seizures were seen in 6% of the busulfan-treated patients and were absent in the TBI group (P = .03). Grade II-IV of acute graft-versus- host disease (GVHD) was similar in the two groups, but grade III-IV and chronic disease was more common in the busulfan-treated group (P = .04). Death associated with GVHD occurred in 17% of the busulfan- treated group and 2% of the TBI group (P = .003). Patients treated with busulfan had a 3-year actuarial survival of 62%, which was worse than the 76% among those treated with TBI (P < .03). In multivariate analysis, poor survival was associated with advanced disease (P < .0001), no posttransplant septicemia (P = .0006), grade II-IV GVHD (P = .006), and busulfan treatment (P < .02). The incidence of relapse did not differ between the two groups. Relapse-free survival was also similar in the two treatment groups on analysis of data from all patients, children, patients with early disease, and those with acute myeloid leukemia, acute lymphoblastic leukemia, and chronic myeloid leukemia. However, in adults (P = .05) and patients with advanced disease (P = .005), leukemia-free survival was significantly better in those treated with TBI. We conclude that patients treated with busulfan have more early toxicity and an increased transplant-related mortality in patients with advanced disease. TBI is therefore the treatment of choice, especially in adults and patients with advanced disease. However, busulfan is an acceptable alternative for patients with early disease and for those in whom TBI is not feasible.

Leukemic patients receiving marrow from HLA-identical sibling donors were randomized to treatment with either busulfan 16 mg/kg (n = 88) or total body irradiation ([TBI] n = 79) in addition to cyclophosphamide 120 mg/kg. The patients were observed for a period of 5 to 9 years. Busulfan-treated patients had an increased risk of veno-occlusive disease (VOD) of the liver (12% v 1%,P = .01) and hemorrhagic cystitis (32% v 10%,P = .003). Acute graft-versus-host disease (GVHD) was similar in the two groups, but the 7-year cumulative incidence of chronic GVHD was 59% in the busulfan-treated group versus 47% in the TBI group (P = .05). Death from GVHD was more common in the busulfan group (22% v 3%, P < .001). Obstructive bronchiolitis occurred in 26% of the busulfan patients but in only 5% of the TBI patients (P < .01). Complete alopecia developed in 8 busulfan patients and partial alopecia in 17, versus five with partial alopecia in the TBI group (P < .001). Cataracts occurred in 5 busulfan-treated patients and 16 TBI patients (P = .02). The incidence of relapse after 7 years was 29% in both groups. Seven-year transplant-related mortality (TRM) in patients with early disease was 21% in the busulfan group and 12% in the TBI group. In patients with more advanced disease, the corresponding figures were 64% and 22%, respectively (P = .004). Leukemia-free survival (LFS) in patients with early disease was 68% in busulfan-treated patients and 66% in TBI patients. However, 7-year LFS in patients with more advanced disease was 17% in the busulfan group versus 49% in the TBI group (P < .01). In patients with chronic myeloid leukemia (CML) in first chronic phase, 7-year LFS was 72% and 83% in the two groups, respectively.