Kim Michele M, Finlay Jarod C, Zhu Timothy C
Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA 19104 ; Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104.
Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA 19104.
Proc SPIE Int Soc Opt Eng. 2015 Mar 2;9308:93080V. doi: 10.1117/12.2079046.
A macroscopic singlet oxygen model for photodynamic therapy (PDT) has been used extensively to calculate the reacted singlet oxygen concentration for various photosensitizers. The four photophysical parameters (ξ, σ, β, δ) and threshold singlet oxygen dose ([O]) can be found for various drugs and drug-light intervals using a fitting algorithm. The input parameters for this model include the fluence, photosensitizer concentration, optical properties, and necrosis radius. An additional input variable of photobleaching was implemented in this study to optimize the results. Photobleaching was measured by using the pre-PDT and post-PDT sensitizer concentrations. Using the RIF model of murine fibrosarcoma, mice were treated with a linear source with fluence rates from 12 - 150 mW/cm and total fluences from 24 - 135 J/cm. The two main drugs investigated were benzoporphyrin derivative monoacid ring A (BPD) and 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a (HPPH). Previously published photophysical parameters were fine-tuned and verified using photobleaching as the additional fitting parameter. Furthermore, photobleaching can be used as an indicator of the robustness of the model for the particular mouse experiment by comparing the experimental and model-calculated photobleaching ratio.
一种用于光动力疗法（PDT）的宏观单线态氧模型已被广泛用于计算各种光敏剂的单线态氧反应浓度。使用拟合算法可以找到各种药物和药物 - 光间隔的四个光物理参数（ξ、σ、β、δ）和阈值单线态氧剂量（[O]）。该模型的输入参数包括通量、光敏剂浓度、光学性质和坏死半径。本研究中引入了光漂白这一额外输入变量以优化结果。通过测量光动力疗法前和光动力疗法后光敏剂的浓度来测定光漂白。使用小鼠纤维肉瘤的RIF模型，用线性光源对小鼠进行治疗，通量率为12 - 150 mW/cm，总通量为24 - 135 J/cm²。研究的两种主要药物是苯并卟啉衍生物单酸环A（BPD）和2 - [1 - 己氧基乙基] - 2 - 去乙烯基焦脱镁叶绿酸 - a（HPPH）。以前公布的光物理参数通过将光漂白作为额外的拟合参数进行了微调并得到验证。此外，通过比较实验和模型计算的光漂白率，光漂白可以用作特定小鼠实验模型稳健性的指标。
