van den Bergh H
Institute of Environmental Engineering, Swiss Federal Institute of Technology, Lausanne, Switzerland.
Endoscopy. 1998 May;30(4):392-407. doi: 10.1055/s-2007-1001289.
Progress in photodynamic therapy (PDT) depends on the development of: (1) photosensitizers, (2) optical devices among which are lasers and light delivery systems, and (3) clinical procedure. The light delivery systems which are the focus of this article are fiberoptic devices developed in Lausanne, Switzerland for use in the endoscopic treatment of cancer or precancerous lesions in the bronchi, the esophagus, the uterus, the cervix, the upper aerodigestive tract and thoracic cavity. Light delivery systems for both surface and interstitial application are presented, together with some of the physical principles on which they are based. Incorporation in these devices of the possibility for in-situ measurement of reflected therapeutic light and/or fluorescence emitted by endogenous and/or exogenous dyes allows for improved light and drug dosimetry, as well as the measurement of photobleaching, local oxygenation and other tissue properties. The necessity of information on tissue optical parameters, as well as the use of simple mathematical models and tissue phantoms, for optimizing light distributing devices is underlined. The devices are optimized for delivering the desired light intensity distribution to the targeted region with minimal losses. In some cases this implies using the device to modify the shape of the hollow organ during PDT, an example of which is given for the case of the esophagus. In another strategy, one adapts the shape of the device to that of the organ, using an elastic balloon catheter. Here examples are given for the uterus, the bronchi and the thoracic cavity. The mechanical properties, the sizes, shapes and materials of the light delivery systems must be optimized for safe use while retaining low cost. Furthermore, the devices must whenever possible be rendered compatible with existing medical technology. A significant improvement in clinical efficacy has been demonstrated in the testing of some of these new fiberoptic light delivery systems. For endoscopic PDT in the hollow organs, the design and optimalization of multiple new approaches to light distribution will continue to lead to improved clinical results.
光动力疗法（PDT）的进展取决于以下几个方面的发展：（1）光敏剂；（2）光学设备，其中包括激光和光传输系统；（3）临床程序。本文重点介绍的光传输系统是在瑞士洛桑开发的光纤设备，用于支气管、食管、子宫、宫颈、上呼吸道和胸腔的癌症或癌前病变的内镜治疗。介绍了用于表面和间质应用的光传输系统，以及它们所基于的一些物理原理。在这些设备中加入原位测量反射治疗光和/或内源性和/或外源性染料发出的荧光的功能，可改善光和药物剂量测定，以及光漂白、局部氧合和其他组织特性的测量。强调了组织光学参数信息以及简单数学模型和组织模型在优化光分布设备方面的必要性。这些设备经过优化，可将所需的光强度分布以最小的损失传递到目标区域。在某些情况下，这意味着在光动力疗法期间使用该设备改变中空器官的形状，文中给出了食管的一个例子。在另一种策略中，使用弹性球囊导管使设备形状与器官形状相适应。这里给出了子宫、支气管和胸腔的例子。光传输系统的机械性能、尺寸、形状和材料必须在保证安全使用的同时进行优化，且成本要低。此外，这些设备应尽可能与现有医疗技术兼容。在测试其中一些新型光纤光传输系统时，已证明临床疗效有显著提高。对于中空器官的内镜光动力疗法，多种光分布新方法的设计和优化将继续带来更好的临床效果。
