Hepatic veno-occlusive disease (VOD) after allogeneic hematopoietic cell transplantation (HCT) in adults conditioned with busulfan (Bu) and cyclophosphamide (Cy) at a single center: A retrospective comparison of oral vs. intravenous Bu

6647 Background: Hepatic VOD is one of potentially fatal toxicities after allogeneic HCT and is caused by high-dose chemotherapeutic agents, one of which is Bu. High interpatient variability following oral administration of Bu (O-Bu), which is ascribed to unpredictable and erratic intestinal absorption, contributes to the occurrence of hepatic VOD. Intravenous administration of Bu (I-Bu) has shown dose assurance with predictable pharmacokinetics. We investigated the occurrence of hepatic VOD after allogeneic HCT in adults conditioned with Bu-Cy and retrospectively compared I-Bu with O-Bu. Methods: All 241 patients, who were conditioned with Bu-Cy and who underwent allogeneic HCT between December 1993 and August 2003 at the Asan Medical Center, were included in this study. The first 187 patients received O-Bu (1 mg/kg x 16 doses), and thereafter 54 patients received I-Bu (Busulfex®, 0.8 mg/dg x 16 doses). Various hemostatic parameters were determined at 5 time points (day –7, 0, 7, 14, and 21). A diagnosis...