Interstitial Intensity Modulated Photodynamic Therapy Phase II

光动力疗法（PDT）是一种利用可见光或近红外光激活光- 一种敏感的药物（光敏剂，PS），反过来，从基态三重态产生活性单线态氧 肿瘤中存在的氧。产生的反应产物诱导组织死亡。理想地 反应性物质将仅在靶体积内产生，导致肿瘤或病变的损伤。 组织，同时最大限度地减少对周围正常组织的损伤。与化疗不同，PDT不会引起 与放射治疗不同，它不会在局部区域造成累积性损伤。当 外部光束用于治疗浅表表面或腔内表面癌症， 光穿透和治疗限于< 10 mm。对于深位肿瘤或大于 厚度为10 mm，需要肿瘤内光递送（间质PDT，I-PDT）来激活PS。

Photodynamic therapy (PDT) is a cancer treatment that utilizes visible or near-infrared light to activate a light- sensitive drug (photosensitizer, PS) that, in turn, creates reactive singlet oxygen species from ground triplet state oxygen that is present in the tumor. The resulting reactive products induce tissue death. Ideally the reactive species will be produced within only the target volume, leading to damage of the tumor or diseased tissues, while minimizing damage to surrounding normal tissue. Unlike chemotherapy, PDT does not cause systemic toxicities, and unlike radiation therapy it does not cause cumulative damage in the local field. When an external light beam is used to treat superficial surface or intracavitary surface cancers, the effective depth of light penetration and treatment is limited to < 10 mm. For deeply seated tumors or tumors that are more than 10 mm in thickness, intra-tumor light delivery (interstitial PDT, I-PDT) is required to activate the PS.