PK simulation R-CHOP-14 versus R-CHOP-21. The pharmacokinetic model is based on median values of pharmacokinetic parameters as follows: K_elm, V₁ (l/kgLBMc), k₁₂, and k₂₁ of 20 patients treated with R-CHOP-14 according to a 2-compartment model. The model was then calculated for 21-day intervals. K_elm indicates elimination constant; V₁ (I/kgLBMc), central distribution volume; k₁₂, first order rate (constant that describes mean transfer from compartment 1 to compartment 2); and k₂₁, first order rate (mean transfer from compartment 2 to compartment 1)