Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, United States of America.
Phys Med Biol. 2020 Apr 14;65(7):075006. doi: 10.1088/1361-6560/ab7632.
Pleural photodynamic therapy (PDT) is performed intraoperatively for the treatment of microscopic disease in patients with malignant pleural mesothelioma. Accurate delivery of light dose is critical to PDT efficiency. As a standard of care, light fluence is delivered to the prescribed fluence using eight isotropic detectors in pre-determined discrete locations inside the pleural cavity that is filled with a dilute Intralipid solution. An optical infrared (IR) navigation system was used to monitor reflective passive markers on a modified and improved treatment delivery wand to track the position of the light source within the treatment cavity during light delivery. This information was used to calculate the light dose, incorporating a constant scattered light dose and using a dual correction method. Calculation methods were extensively compared for eight detector locations and seven patient case studies. The light fluence uniformity was also quantified by representing the unraveled three-dimensional geometry on a two-dimensional plane. Calculated light fluence at the end of treatment delivery was compared to measured values from isotropic detectors. Using a constant scattered dose for all detector locations along with a dual correction method, the difference between calculated and measured values for each detector was within 15%. Primary light dose alone does not fully account for the light delivered inside the cavity. This is useful in determining the light dose delivered to areas of the pleural cavity between detector locations, and can serve to improve treatment delivery with implementation in real-time in the surgical setting. We concluded that the standard deviation of light fluence uniformity for this method of pleural PDT is 10%.
胸膜光动力疗法 (PDT) 是在手术过程中进行的，用于治疗恶性胸膜间皮瘤患者的显微镜下疾病。准确输送光剂量对 PDT 效率至关重要。作为一种护理标准，使用腔内充满稀释的 Intralipid 溶液的八个各向同性探测器在胸膜腔内预定的离散位置输送光剂量。光学近红外 (IR) 导航系统用于监测改良和改进的治疗输送手柄上的反射无源标记，以跟踪光源在光输送过程中在治疗腔内的位置。该信息用于计算光剂量，包括恒定散射光剂量并使用双校正方法。对八个探测器位置和七个患者病例研究进行了广泛的计算方法比较。还通过在二维平面上表示展开的三维几何形状来量化光通量均匀性。将治疗输送结束时计算的光通量与各向同性探测器的测量值进行比较。对于所有探测器位置使用恒定散射剂量和双校正方法，每个探测器的计算值和测量值之间的差异在 15%以内。单独的初级光剂量不能完全说明腔内输送的光。这对于确定探测器位置之间的胸膜腔内的光输送区域很有用，并且可以在手术环境中实时实施，以提高治疗输送。我们得出结论，这种胸膜 PDT 的光通量均匀性标准偏差为 10%。
