A TRANSIENT MATHEMATICAL-MODEL OF OXYGEN DEPLETION DURING PHOTODYNAMIC THERAPY

A transient one-dimensional mathematical model is presented to help vi sualize the qualitative and quantitative effects on intercapillary tis sue undergoing photodynamic therapy (PDT). The model is solved by a Cr ank-Nicholson finite difference formulation to provide time-dependent concentrations of the Type II mechanism's photo-oxidation species in t he tissue surrounding a capillary, The time-dependent solution allows educated decisions to be made as to the optimum timing of light fracti onation (on/off) cycles, Qualitative and quantitative optimization of the PDT process is considered along with a case study of data in the l iterature, the main goal being to provide optimized light therapy regi mens for eventual clinical use. (C) 1995 by Radiation Research Society