Comparison of serum methotrexate concentration and proportion of delayed elimination group at 48 hours. aMethotrexate. *The cycles had plasma MTX concentration at 48hours are 70 cycles, 21 cycles were delayed elimination group. At the 48 hours, the percent of delayed elimination group was compared between MTX concentration greater than 2 μM and less than 2 μM. It was also compared between MTX concentrationgreater than 5 μM and less than 5 μM