van Veen Robert L P, Aalders Maurice C G, Pasma Kasper L, Siersema Peter D, Haringsma Jelle, van de Vrie Wim, Gabeler Edward E E, Robinson Dominic J, Sterenborg Henricus J C M
Photodynamic Therapy and Optical Spectroscopy Program, Erasmus MC, Rotterdam, The Netherlands.
Lasers Surg Med. 2002;31(5):299-304. doi: 10.1002/lsm.10129.
Previous studies with PhotoDynamic Therapy (PDT) in bladder and bronchi have shown that due to scattering and reflection, the actually delivered fluence rate on the surface in a hollow organ can be significantly higher than expected. In this pilot study, we investigated the differences between the primary calculated and the actual measured fluence rate during PDT of Barrett's Esophagus (BE) using 23 independent clinical measurements in 15 patients.
STUDY DESIGN/MATERIALS AND METHODS: A KTP-dye module laser at 630 nm was used as light source. Light delivery was performed using a cylindrical light diffuser inserted in the center of an inflatable transparent balloon with a length corresponding to the length of the Barrett's epithelium. The total light output power of the cylindrical diffuser was calibrated using an integrating sphere to deliver a primary fluence rate of 100 mW cm(-2). Two fiber-optic pseudo sphere isotropic detectors were placed on the balloon and were used to measure fluence rate at the surface of the esophageal wall during PDT.
The actual fluence rate measured was 1.5-3.9 times higher than the primary fluence rate for 630 nm. In general, the fluence rate amplification factor decreased with increasing redness of the tissue and was less for shorter diffusers. Fluence rate variations in time were observed which coincided with patients coughing, movement, and esophageal spasms. These factors combined with inter patient variability of the fluence rate measured appears to justify the routine application of this technique in PDT of BE.
先前在膀胱和支气管中进行光动力疗法（PDT）的研究表明，由于散射和反射，中空器官表面实际传递的能量通量率可能显著高于预期。在这项初步研究中，我们通过对15名患者进行23次独立的临床测量，研究了巴雷特食管（BE）光动力疗法期间初始计算的能量通量率与实际测量的能量通量率之间的差异。
研究设计/材料与方法：使用波长为630 nm的KTP染料模块激光器作为光源。通过将圆柱形光扩散器插入可充气透明球囊的中心进行光传输，球囊长度与巴雷特上皮的长度相对应。使用积分球校准圆柱形扩散器的总光输出功率，以提供100 mW/cm²的初始能量通量率。在球囊上放置两个光纤伪球形各向同性探测器，用于在光动力疗法期间测量食管壁表面的能量通量率。
对于630 nm，实际测量的能量通量率比初始能量通量率高1.5至3.9倍。一般来说，能量通量率放大系数随着组织发红程度的增加而降低，对于较短的扩散器则较小。观察到能量通量率随时间的变化，这与患者咳嗽、移动和食管痉挛一致。这些因素与测量的患者间能量通量率变异性相结合，似乎证明了该技术在巴雷特食管光动力疗法中的常规应用是合理的。
