[Efficacy of allogeneic hematopoietic stem cell transplantation based on a total body irradiation conditioning treatment regimen for adult acute lymphocytic leukemia].

Objective: To analyze the efficacy of allo-HSCT with total body irradiation (TBI) and chemotherapy alone in the treatment of adult ALL and to explore the factors affecting prognosis. Methods: The clinical data of 95 adult patients with ALL who underwent allo-HSCT from January 2015 to August 2022 were included. According to the conditioning regimen, the patients were divided into two groups: the TBI plus cyclophosphamide (TBI/Cy) group ( n =53) and the busulfan plus cyclophosphamide (Bu/Cy) group ( n =42). Hematopoietic reconstitution after transplantation, GVHD, transplantation-related complications, relapse rate (RR), non-relapse mortality (NRM), OS, and LFS were compared, and the factors related to prognosis were analyzed. Results: The median time of neutrophil engraftment was 14 (10-25) days in the TBI/Cy group and 14 (10-24) days in the Bu/Cy group ( P =0.106). The median time of megakaryocyte engraftment was 17 (10-42) days in the TBI/Cy group and 19 (11-42) days in the Bu/Cy group ( P =0.488). The incidence of grade Ⅱ-Ⅳ acute GVHD (aGVHD) in the TBI/Cy and Bu/Cy groups was 41.5% and 35.7%, respectively ( P =0.565). The incidence of grade Ⅲ-Ⅳ aGVHD in these two groups was 24.5% and 4.8%, respectively ( P =0.009). The incidence of severe chronic GVHD in the two groups was 16.7% and 13.5%, respectively ( P =0.689). The incidence of cytomegalovirus infection, Epstein-Barr virus infection, severe infection, and hemorrhagic cystitis in the two groups was 41.5% and 35.7% ( P =0.565), 34.0% and 35.7% ( P =0.859), 43.4% and 33.3% ( P =0.318), and 20.8% and 50.0% ( P =0.003), respectively. The median follow-up time was 37.1 months and 53.3 months in the TBI/Cy and Bu/Cy groups, respectively. The 2-year cumulative RR was 17.0% in the TBI/Cy group and 42.9% in the Bu/Cy group ( P =0.017). The 2-year cumulative NRM was 24.5% and 7.1%, respectively ( P =0.120). The 2-year LFS was 58.5% and 50.0%, respectively ( P =0.466). The 2-year OS rate was 69.8% and 64.3%, respectively ( P =0.697). In the multivariate analysis, the conditioning regimen containing TBI was a protective factor for relapse after transplantation ( HR =0.304, 95% CI 0.135-0.688, P =0.004), whereas the effect on NRM was not significant ( HR =1.393, 95% CI 0.355-5.462, P =0.634). Infection was an independent risk factor for OS after allo-HSCT in adult patients with ALL. Conclusion: allo-HSCT based on TBI conditioning regimen had lower relapse rate and lower incidence of hemorrhagic cystitis for adult ALL, compared with chemotherapy regimen. While the incidence o grade Ⅲ/Ⅳ aGVHD was hgher in TBI conditioning regimen than that in chemotherapy regimen.