Liang Xing, Wang Ken Kang-Hsin, Zhu Timothy C
Department of Radiation Oncology, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, PA, USA 19104.
Proc SPIE Int Soc Opt Eng. 2012 Feb 13;8210. doi: 10.1117/12.908317.
Photodynamic therapy (PDT) is an important treatment modality for cancer and other localized diseases. In addition to PDT dose, singlet oxygen (O) concentration is used as an explicit PDT dosimetry quantity, because O is the major cytotoxic agent in photodynamic therapy, and the reaction between O and tumor tissues/cells determines the treatment efficacy. O concentration 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 of O. The singlet oxygen concentration profile was calculated iteratively by comparing the model with the measurements based on mice experiments, to obtain the apparent reacted O concentration 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 reacted O concentrations.
光动力疗法（PDT）是治疗癌症和其他局部疾病的一种重要治疗方式。除了PDT剂量外，单线态氧（O）浓度被用作明确的PDT剂量测定量，因为O是光动力疗法中的主要细胞毒性剂，并且O与肿瘤组织/细胞之间的反应决定了治疗效果。O浓度可通过PDT模型获得，该模型包括组织中光传输的扩散方程和单线态氧生成的宏观动力学方程。该模型由COMSOL使用有限元方法（FEM）实现。在动力学方程中，明确确定了5个光生理参数以预测O的生成。通过将模型与基于小鼠实验的测量结果进行比较，迭代计算单线态氧浓度分布，以获得表观反应O浓度作为明确的PDT剂量测定量。使用该模型测试了两种光敏剂，包括血卟啉和维替泊芬，以确定它们的光生理参数和反应O浓度。
