Dimofte Andreea, Zhu Timothy C, Hahn Stephen M, Lustig Robert A
Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania 19104-4283, USA.
Lasers Surg Med. 2002;31(5):305-12. doi: 10.1002/lsm.10115.
To measure the fluence at tissue surface for patients in our Phase II clinical trial of motexafin lutetium (MLu)-mediated chest wall photodynamic therapy for recurrent breast carcinoma and to compare it to the calculated irradiance.
STUDY DESIGN/MATERIALS AND METHODS: The spatial and time dependence of light fluence (rate) was monitored in vivo on the chest wall surface using isotropic detectors in five patients. Patients were given MLu either 4 mg/kg with light at 18 hours or 5 mg/kg with light at 24 hours using an irradiance of 150 J/cm(2) at 730 nm, with an incident fluence rate of 75 mW/cm(2). The ratio of fluence rate to the incident fluence rate was determined at the center of the treatment field. This ratio was used to estimate the effective attenuation coefficient, mu (eff).
The mean and standard deviation of the ratio for all patients was 1.6 +/- 0.2. The corresponding range of mu (eff) was between 0.87 and 2.1 cm(-1), assuming reduced scattering coefficient, mu (s) = 4 cm(-1).
A conversion factor was determined to convert the irradiance to fluence rate on the tissue surface. However, the fluence (or the ratio) on patient surface varied by 70% due to the heterogeneity of optical properties. This supports the use of real-time in vivo dosimetry during photodynamic therapy.
在我们开展的用于复发性乳腺癌的莫替沙芬镥（MLu）介导的胸壁光动力治疗II期临床试验中，测量患者组织表面的光通量，并将其与计算出的辐照度进行比较。
研究设计/材料与方法：使用各向同性探测器在5例患者的胸壁表面对光通量（率）的空间和时间依赖性进行体内监测。患者分别接受4mg/kg的MLu并在18小时后进行光照，或接受5mg/kg的MLu并在24小时后进行光照，使用730nm波长、150J/cm²的辐照度，入射光通量率为75mW/cm²。在治疗区域中心确定光通量率与入射光通量率的比值。该比值用于估算有效衰减系数μ（eff）。
所有患者该比值的均值和标准差为1.6±0.2。假设散射系数μ（s）=4cm⁻¹，μ（eff）的相应范围在0.87至2.1cm⁻¹之间。
确定了一个转换因子，用于将辐照度转换为组织表面的光通量率。然而，由于光学特性的异质性，患者表面的光通量（或该比值）变化了70%。这支持在光动力治疗期间使用实时体内剂量测定法。
