Real-Time PDT Dosimetry with Feedback Light Delivery

带反馈光传输的实时 PDT 剂量测定

• 批准号: 7082947
• 负责人: Timothy C. Zhu
• 金额: $ 30.57万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-06-20 至 2009-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7082947
• 关键词: atomic absorption spectrometry; bioengineering /biomedical engineering; bioimaging /biomedical imaging; clinical research; clinical trial phase I; computer assisted patient care; computer program /software; fiber optics; fluorescence spectrometry; human subject; human therapy evaluation; image guided surgery /therapy; light scattering; miniature biomedical equipment; neoplasm /cancer photoradiation therapy; optics; oxygen transport; pharmacokinetics; photosensitizing agents; prostate neoplasms; radiation therapy dosage; rectum /anus; therapy adverse effect; ultrasonography; urethra

DESCRIPTION (provided by applicant): The overall objective of this proposal is to develop an integrated system to optimize PDT dose for interstitial photodynamic therapy (PDT). We explore an explicit method to characterize the PDT dose. The explicit PDT dose is essentially the product of drug concentration and light fluence for a given photosensitizer and tissue oxygenation. To quickly determine the spatial distribution of tissue optical properties in-vivo at the treatment wavelength, we plan to develop a motorized device consists of multiple detectors and point sources. To determine the spatial distribution of drug concentration in-vivo, we plan to develop a fluorescence spectroimaging system. In addition, we plan to develop an absorption spectroimaging system to determine the distribution of absorption spectra of tissue. Proper analysis of the absorption spectrum determines tissue oxygenation, and also provides another estimate of the photosensitizer concentration in the prostate gland. To determine the temporal-spatial distribution of light fluence rate, we use our existing in-vivo light dosimetry system in combination the multi-detector probes. The measured results can be compared with calculations using information about tissue optical properties and a suitable light fluence algorithm in heterogeneous medium. We hypothesize that PDT dose, once above a threshold dose, correlates to the tumor necrosis. We also hypothesize that there are heterogeneities of both optical properties and drug concentration within the treatment volume (e.g., prostate gland). This requires in-situ PDT dosimetry (of light fluence rate and drug distribution), feedback, and light source adjustment as part of the integrated system. With an accurate calculation of the PDT dose and the use of optimization methods, we can adjust the light source weights to achieve the most efficacious distribution of PDT dose, treating the tumor to dose prescription yet avoiding injury to normal structure.

描述（由申请人提供）：该提案的总体目标是开发一种集成系统来优化间质光动力疗法（PDT）的PDT剂量。 我们探索一种明确的方法来表征 PDT 剂量。 显式 PDT 剂量本质上是给定光敏剂和组织氧合作用的药物浓度和光通量的乘积。 为了快速确定治疗波长下体内组织光学特性的空间分布，我们计划开发一种由多个探测器和点源组成的机动装置。 为了确定体内药物浓度的空间分布，我们计划开发荧光光谱成像系统。 此外，我们计划开发吸收光谱成像系统来确定组织吸收光谱的分布。 对吸收光谱的正确分析可以确定组织氧合，并且还可以提供前列腺中光敏剂浓度的另一种估计。 为了确定光注量率的时空分布，我们使用现有的体内光剂量测定系统结合多探测器探头。 测量结果可以与使用有关组织光学特性的信息和异质介质中合适的光注量算法的计算结果进行比较。 我们假设 PDT 剂量一旦高于阈值剂量，就会与肿瘤坏死相关。 我们还假设治疗体积（例如前列腺）内的光学特性和药物浓度都存在异质性。 这需要原位 PDT 剂量测定（光通量率和药物分布）、反馈和光源调整作为集成系统的一部分。 通过精确计算PDT剂量并采用优化方法，我们可以调整光源权重以实现最有效的PDT剂量分布，按照剂量处方治疗肿瘤，同时避免损伤正常结构。