Dimofte Andreea, Zhu Timothy C, Finlay Jarod C, Cullighan Melissa, Edmonds Christine E, Friedberg Joseph S, Cengel Keith, Hahn Stephen M
Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA.
Department of Surgery, University of Pennsylvania, Philadelphia, PA.
Proc SPIE Int Soc Opt Eng. 2009 Jan 24;7164. doi: 10.1117/12.809548.
light dosimetry for patients undergoing photodynamic therapy (PDT) is one of the critical dosimetry quantities for predicting PDT outcome. This study examines the relationship between the PDT treatment time and thoracic treatment volume and surface area for patients undergoing pleural PDT. In addition, the mean light fluence (rate) and its accuracy were quantified. The patients studied here were enrolled in Phase II clinical trial of Photofrin-mediated PDT for the treatment of non-small cell lung cancer with pleural effusion. The ages of the patients studied varied from 34 to 69 years old. All patients were administered 2mg per kg body weight Photoprin 24 hours before the surgery. Patients undergoing photodynamic therapy (PDT) are treated with laser light with a light fluence of 60 J/cm at 630nm. Fluence rate (mW/cm) and cumulative fluence (J/cm) was monitored at 7 different sites during the entire light treatment delivery. Isotropic detectors were used for light dosimetry. The anisotropy of each isotropic detector was found to be within 30%. The mean fluence rate deliver varied from 37.84 to 94.05 mW/cm and treatment time varied from 1762 to 5232s. We found a linear correlation between the total treatment time and the treatment area: t (sec) = 4.80 A (cm). A similar correlation exists between the treatment time and the treatment volume: t (sec) = 2.33 V (cm). The results can be explained using an integrating sphere theory and the measured tissue optical properties assuming that the saline liquid has a mean absorption coefficient of 0.05 cm. Our long term accuracy studies confirmed light fluence rate measurement accuracy of ±10%. The results can be used as a clinical guideline for future pleural PDT treatment.
接受光动力疗法（PDT）的患者的光剂量测定是预测PDT疗效的关键剂量测定量之一。本研究探讨了接受胸膜PDT的患者的PDT治疗时间与胸部治疗体积和表面积之间的关系。此外，还对平均光通量（率）及其准确性进行了量化。此处研究的患者参加了Photofrin介导的PDT治疗伴有胸腔积液的非小细胞肺癌的II期临床试验。所研究患者的年龄在34至69岁之间。所有患者在手术前24小时按每公斤体重2mg给予Photoprin。接受光动力疗法（PDT）的患者用波长630nm、光通量为60J/cm的激光进行治疗。在整个光治疗过程中，在7个不同部位监测光通量率（mW/cm）和累积光通量（J/cm）。使用各向同性探测器进行光剂量测定。发现每个各向同性探测器的各向异性在30%以内。平均光通量率在37.84至94.05mW/cm之间变化，治疗时间在1762至5232秒之间变化。我们发现总治疗时间与治疗面积之间存在线性相关性：t（秒）=4.80A（平方厘米）。治疗时间与治疗体积之间也存在类似的相关性：t（秒）=2.33V（立方厘米）。假设生理盐水的平均吸收系数为0.05cm，可使用积分球理论和测量的组织光学特性来解释这些结果。我们的长期准确性研究证实光通量率测量的准确性为±10%。这些结果可作为未来胸膜PDT治疗的临床指南。
