To evaluate the prognostic impact of melphalan dose and total body irradiation (TBI) in acute lymphoblastic leukemia (ALL) patients undergoing reduced-intensity allogeneic transplantation, we retrospectively compared the outcomes between higher-dose melphalan (120-140 mg/m2) with (HDM/TBI+, n = 118) or without 2-4 Gy TBI (HDM/TBI-, n = 152) and lower-dose melphalan (80-110 mg/m2) with TBI (LDM/TBI+, n = 237). At 3 years, the overall survival was 49.6% in the HDM/TBI+, 51.7% in the HDM/TBI-, and 47.3% in the LDM/TBI + groups (p = .67). The relapse rate and non-relapse mortality were comparable among the three groups. Multivariate analysis revealed that conditioning regimen was not associated with overall survival, relapse, and non-relapse mortality; however, central nervous system complication was less frequent with LDM/TBI + than with HDM/TBI+. Our findings suggest reduced-intensity conditioning with LDM/TBI + might be a reasonable option, especially in vulnerable ALL patients, with similar transplant outcomes to HDM with or without TBI.
Keywords: Transplant toxicity; clinical results; lymphoid leukemia.