Photodynamic therapy (PDT) is a clinically approved cancer therapy, based on a photochemical reaction between a light activatable molecule or photosensitizer, light, and molecular oxygen. When these three harmless components are present together, reactive oxygen species are formed. These can directly damage cells and/or vasculature, and induce inflammatory and immune responses. PDT is a two-stage procedure, which starts with photosensitizer administration followed by a locally directed light exposure, with the aim of confined tumor destruction. Since its regulatory approval, over 30 years ago, PDT has been the subject of numerous studies and has proven to be an effective form of cancer therapy. This review provides an overview of the clinical trials conducted over the last 10 years, illustrating how PDT is applied in the clinic today. Furthermore, examples from ongoing clinical trials and the most recent preclinical studies are presented, to show the directions, in which PDT is headed, in the near and distant future. Despite the clinical success reported, PDT is still currently underutilized in the clinic. We also discuss the factors that hamper the exploration of this effective therapy and what should be changed to render it a more effective and more widely available option for patients.

中文翻译：

---

肿瘤光动力疗法：基本原理、临床现状和未来方向

光动力疗法 (PDT) 是一种临床批准的癌症疗法，它基于光可激活分子或光敏剂、光和分子氧之间的光化学反应。当这三种无害成分一起存在时，就会形成活性氧。这些可以直接损害细胞和/或脉管系统，并诱导炎症和免疫反应。PDT 是一个两阶段的程序，首先是光敏剂给药，然后是局部定向光照射，目的是限制肿瘤破坏。自 30 多年前获得监管部门批准以来，PDT 已成为众多研究的主题，并已被证明是一种有效的癌症治疗形式。这篇综述概述了过去 10 年进行的临床试验，说明了 PDT 如何在当今的临床中应用。此外，介绍了正在进行的临床试验和最近的临床前研究的例子，以展示 PDT 在近期和遥远的未来的发展方向。尽管报告了临床成功，但 PDT 目前在临床上仍未得到充分利用。我们还讨论了阻碍探索这种有效疗法的因素，以及应该做出哪些改变以使其成为对患者更有效和更广泛可用的选择。