Total body irradiation plus cyclophosphamide versus busulphan with cyclophosphamide as conditioning regimen for patients with leukemia undergoing allogeneic stem cell transplantation: a meta-analysis.

The aim of the study was to compare the therapeutic efficacy of total body irradiation (TBI)/cyclophosphamide (CY) versus BU/CY as conditioning regimen for leukemia. We electronically searched the Cochrane Central Register of Controlled Trials, Medline, Embase, CIBMTR and critically appraised all relevant articles (1990.01-2009.04). Comparative studies were evaluated on clinical therapeutic effects of TBI/CY and busulphan BU/CY regimens with assessement of engraftment, relapse, complications, and disease-free survival (DFS). Eighteen trials totaling 3172 patients have been assessed. Pooled comparisons of studies indicated that for patients with acute leukemia (ALL and AML), the TBI/CY regimen lead to lower rates of leukemia relapse, lower transplant-related mortality (TRM), and higher DFS, while for chronic myeloid leukemia (CML), the TBI/CY regimen had a higher rate of leukemia relapse, lower TRM, and similar DFS. The TBI/CY regimen was associated with similar occurrence of engraftment, acute and chronic graft-versus-host disease (GVHD), but with higher rates of cataract [odds ratio (OR) 12.69, p = 0.01], interstitial pneumonitis, later growth or development problems [OR 5.04, p = 0.008]. BU/CY regimen was associated with higher rates of complications like liver veno-occlusive disease [OR 0.43, p < 0.00001], hemorrhagic cystitis, and TRM. Our meta-analysis confirmed that different regimens and type of leukemia may affect the complications and outcome. An analysis of the effects of other regimens need to be carried out by large sample and well-designed clinical trials.