title: Singlet oxygen dosimetry modeling for photodynamic therapy.
abstract: Photodynamic therapy (PDT) is an important treatment modality for cancer and other localized diseases. In addition to PDT dose, singlet oxygen (1O2) concentration is used as an explicit PDT dosimetry quantity, because1O2is the major cytotoxic agent in photodynamic therapy, and the reaction between1O2and tumor tissues/cells determines the treatment efficacy.1O2concentration can be obtained by the PDT model, which includes diffusion equation for the light transport in tissue and macroscopic kinetic equations for the generation of the singlet oxygen. This model was implemented using finite-element method (FEM) by COMSOL. In the kinetic equations, 5 photo-physiological parameters were determined explicitly to predict the generation of1O2. The singlet oxygen concentration profile was calculated iteratively by comparing the model with the measurements based on mice experiments, to obtain the apparent reacted1O2concentration as an explicit PDT dosimetry quantity. Two photo sensitizers including Photofrin and BPD Verteporfin, were tested using this model to determine their photo-physiological parameters and the reacted1O2concentrations.
authors.affiliation: Department of Radiation Oncology, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, PA, USA 19104.
authors.forename: Xing
authors.initials: X
authors.lastname: Liang
authors.affiliation: Department of Radiation Oncology, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, PA, USA 19104.
authors.forename: Ken Kang-Hsin
authors.initials: KK
authors.lastname: Wang
authors.affiliation: Department of Radiation Oncology, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, PA, USA 19104.
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Zhu
keywords: Photodynamic therapy; Photosensitizer; Singlet oxygen concentration