Clinical Outcomes of Allogeneic Stem Cell Transplantation using Simplified Total Body Irradiation plus Chemotherapy in Adult Acute Leukemia; King Chulalongkorn Memorial Hospital experience

Abstract

Background: Total body irradiation (TBI) is the important part of conditioning regimen before stem cell transplant in acute leukemia. Recently, we simplified TBI technique in our center. So, we conducted study to assess clinical outcome of TBI plus chemotherapy in adult acute leukemia.

Objective: The primary outcome was a 3-year overall survival (OS) and the secondary outcomes were engraftment rate, relapsed rate, acute graft-versus-host disease (GVHD), chronic GVHD, and late radiation toxicity.

Material and methods: We retrieved the retrospective data of post-TBI patients in adult acute leukemia between June 2014 and June 2016.

Results: Total enrollment was 12 adult acute leukemia patients (4 patients with new acute lymphoblastic leukemia (ALL), 4 patients with new acute myeloid leukemia (AML), and 4 patients with relapsed AML) with a median follow-up 3 years. Three-year OS was 74% (100% in new ALL, 100% in new AML, and 25% in relapsed AML). White blood cell (WBC) engraftment was 100%. Early relapsed rate within first year of transplantation was 25%, while late relapsed rate after first year of transplantation was 16.7%. Acute GVHD was 16.7% and finally turned to chronic GVHD. Chronic GVHD was affected 50% of all patients and 66.7% of surviving patients. There was neither toxicity grade ≥3of radiation pneumonitis nor a record of late radiation toxicity.

Conclusion: This TBI technique produced good transplantation outcomes in new adult acute leukemia group, accompanied by good tolerance. However, there were poorer outcomes in recurrent adult acute myeloid leukemia setting.