Monitoring of Busulphan Concentrations in Children Undergone Hematopoietic Stem Cell Transplantation: Unicentric Experience over 10 years.

Background And Objectives: The aim of this report is to describe the experience in the management of busulphan-based conditioning regimen administered before hematopoietic stem cell transplantation (HSCT) in children.

Methods: We report the values of the first dose AUC (area under the concentration-time curve, normal target between 3600 and 4800 ng·h/mL) in children treated with oral and intravenous busulphan, and we analyze the impact of some clinical variables in this cohort of patients.

Results: 82 children treated with busulphan before HSCT were eligible for the study: 57 received oral busulphan with a mean AUC of 3586 ng·h/mL, while 25 received intravenous busulphan with a mean AUC of 4158 ng·h/mL. Dose adjustment was based on first dose AUC. The dose was increased in 36 children (43.9%) and decreased in 26 patients (31.7%). Age at HSCT (P = 0.015), cumulative dose of busulphan as mg/m (P < 0.001), busulphan dose prescribed as mg/Kg (P = 0.001), intravenous busulphan administration (P < 0.001), type of stem source cells (P = 0.016), and type of HSCT (P = 0.03) were associated with AUC levels. No statistically significant differences were found between transplant-related toxicity, acute and chronic graft versus host disease, engraftment, and AUC levels.

Conclusions: We concluded that older age at HSCT, intravenous administration of busulphan, cumulative, and prescribed dose of busulphan are associated with higher AUC levels. The absence of significant correlations between toxic events, graft failure, and AUC suggests the efficacy of busulphan concentrations monitoring in our patients.