[Comparison between single-dose and hyperfractionated total-body irradiation for the conditioning of allogenic grafts of the bone marrow. A retrospective study of 54 patients with malignant hematologic diseases].

The present study is a retrospective analysis of 54 patients with hematological malignancies who were treated by total body irradiation (TBI) and allogenic bone-marrow transplantation from 1982-1986. Patients were not randomly assigned to receive either single dose total body irradiation (STBI) (10 Gy x 1-4 cGy/min-lung dose 8 Gy) or hyperfractionated total body irradiation (HTBI) (1,20 Gy x 11-3 fractions/day-lung dose 9 Gy). Thirty one patients received STBI and 23 a HTBI regimen. Despite the presence of a large proportion of patients with a high risk of leukemic relapse in the HTBI group, the incidence of relapse did not differ significantly in the two groups: STBI (16%), HTBI (21%). Lung and liver toxicity were predominant in the STBI group. Interstitial pneumonitis occurred in 45% of the STBI patients versus 13% in the HTBI group. This difference remains significant when adjusted to the incidence of graft versus host disease (GVHD) in the two groups. Three cases of veino-occlusive disease were observed (10%), but only in the STBI group. Even when differences in age and the frequency of GVHD are considered in the two groups, these findings suggest that HTBI is at least as effective as STBI and that toxicity is reduced with this schedule.