Methotrexate Pharmacokinetics and Survival in Osteosarcomat

Procedure This study included 44 patients (479 courses) who received a median dose of 5.92 g/m of MTX (interquartile range (IQR) 2.37 g/m) in a 4-hr infusion. The mean area under the concentration–time curve (AUC) estimated by parametric methods (non-parametric expectation maximization, NPEM), and the mean concentration at the end of the infusion were considered to be the exposure parameters. Tumor response was recorded as disease-free survival (DFS), overall survival (OS), and histologic tumor response. The relationship between MTX exposure and survival parameters was analyzed by Cox regression.