Patients:
Patients with high-risk TM receiving F-araA based conditioning regimen prior to HCT between 2010 and 2019 were recruited after obtaining written informed assent or consent from the patient/parents respectively. This study was approved by the Institutional review board. All patients were risk-stratified based on Vellore risk classification as published previously 24. All patients received F-araA at a dose of 40mg/m2/day x 4 days as 1hr infusion from day -5 to day -2 and Treo as 14g/m2/day x 3 days at the rate 5g/hr from day -5 to day -3 and a single dose of Thiotepa on day -6 prior to HCT. Cyclosporine and short course methotrexate was used as GVHD prophylaxis 1.