Grant W E, Speight P M, Hopper C, Bown S G
National Medical Laser Centre, University College, London Medical School, UK.
Int J Cancer. 1997 Jun 11;71(6):937-42. doi: 10.1002/(sici)1097-0215(19970611)71:6<937::aid-ijc4>3.0.co;2-z.
It has often been claimed that photodynamic therapy (PDT) produces selective destruction of small cancers without affecting the adjacent normal tissue. The objective of our work was to treat small cancers of the oral cavity with PDT and subsequently excise the treated areas for histological studies of tumour and adjacent normal tissue exposed to the same light dose. Eleven patients with histologically proven T1NO oral squamous-cell carcinomas were treated with PDT, using Photofrin as a sensitiser. The tumours plus a surrounding cuff of normal tissue were exposed to 50 J/cm2 non-thermal laser light at 630 nm delivered by surface illumination and the treated areas subsequently excised. Histological staining and image analysis were used to determine the nature and extent of injury. No macroscopic distinction was evident between tumour and normal tissue exposed to light. Histologically, replacement of superficial epithelium, tumour and connective tissue with a fibrinous necrotic slough was seen. There was also loss of endothelium from small vessels, with haemorrhage and thrombosis. Preservation of subepithelial collagen and elastin was demonstrated with EVG staining. No evidence of selective tumour necrosis was found. Although depth of injury was variable, full thickness mucosal necrosis occurred in all cases.
人们常常声称光动力疗法（PDT）能选择性地破坏小肿瘤，而不影响相邻的正常组织。我们这项工作的目的是用PDT治疗口腔小肿瘤，随后切除治疗区域，以便对暴露于相同光剂量下的肿瘤组织和相邻正常组织进行组织学研究。11例经组织学证实为T1NO期口腔鳞状细胞癌的患者接受了PDT治疗，使用卟吩姆钠作为敏化剂。通过表面照射将肿瘤及其周围一圈正常组织暴露于630nm波长、50J/cm²的非热激光下，随后切除治疗区域。采用组织学染色和图像分析来确定损伤的性质和程度。暴露于光线下的肿瘤组织和正常组织在肉眼上并无明显区别。组织学检查发现，浅表上皮、肿瘤组织和结缔组织被纤维蛋白样坏死性痂皮所取代。小血管内皮也有缺失，并伴有出血和血栓形成。弹性Van Gieson（EVG）染色显示上皮下胶原蛋白和弹性蛋白得以保留。未发现有选择性肿瘤坏死的证据。尽管损伤深度各不相同，但所有病例均出现了全层黏膜坏死。
