Optimal dynamic control approach in a multi-objective therapeutic scenario: Application to drug delivery in the treatment of prostate cancer
Fig 2
Schematic representation of the state variables and control input for the pharmakinetic-pharmacodynamic model of the testosterone effects of Triptorelin (left) and model parameter estimates (right).
CTRP, serum concentrations of Triptorelin; CL, apparent total clearance; Vc, VT1, and VT2, apparent volumes of distribution of the central, shallow, and deep peripheral compartments, respectively; CLD1 and CLD2, distribution clearances between the central and peripheral compartments; RT, total receptors; RT0, total receptors at baseline; TST0, baseline testosterone level; KD, receptor equilibrium dissociation constant of triptorelin; DR, down-regulation process; DR_50, the value that elicits a 50% maximal reduction in kS_R for a given amount of total receptors; kS_R, zero-order rate constants of receptor synthesis; kD_R, first-order rate constants of degradation; kS_R, zero-order rate constants of testosterone synthesis; kD_T, first-order rate constants of testosterone degradation; kin, zero-order rate production of testosterone independent from gonadotropins; AGN, ratio between the endogenous agonist concentration and its receptor equilibrium dissociation constant; FDB, feedback.