Figure count: Four
What is already known about this subject:
High-dose methotrexate is commonly used in acute lymphoblastic leukemia. The target 24-hours methotrexate concentrations were set at 33 μmol/L for 3 g/m2 dose group and 65 μmol/L for 5 g/m2 dose group. The relationship between target 24-hours methotrexate concentration and methotrexate excretion delay with survival have not been fully confirmed.
What this study adds:
Achieving the target 24-hours methotrexate concentration during high-dose methotrexate therapy is not the useful indicator to predict the survival of acute lymphoblastic leukemia patients. Patients with more than 20% of methotrexate excretion delay courses had significant worse prognosis. More serious consideration should be taking into account on the leucovorin rescue.