人膀胱癌光动力学治疗的电镜观察

电镜观察15例光动力学治疗前后膀胱移行细胞癌的活检材料,证实此治疗对膀胱癌有显著作用。肿瘤组织内的毛细血管对光动力学作用最为敏感,照光20min后即出现明显损伤,24h后,毛细血管几乎完全坏死崩解。癌细胞的破坏出现较晚,迟于毛细血管。治疗4d后肿瘤组织水肿、出血,几全部坏死。治疗21～80d后,瘤床仍水肿并有出血及坏死物质复盖。表明血管的结构损伤与功能障碍在肿瘤光动力学治疗机理中起主要作用。

Electron Microscopic Observation on Human Bladder Cancer Tissue after Photodynamic Therapy

Biopsy of transitional cell carcinoma of urinary bladder taken before and after photodynamic therapy (PDT) from 15 patients were examined by electron microscopy. It has been demonstrated that this tumor is highly sensitive to PDT using hematoporphyrin derivative (HPD, China-made) and laser irradiation. Within the tumor tissues, the capillaries are most sensitive to PDT action, displaying distinct injuries of endothelium immediately after 20 minutes irradiation. 24 h after PDT, almost all capillaries became necrotic. The cancer cells are less sensitive to PDT, showing destruction later and less serious as compared with that of capillaries. 4 days after PDT, the cancer tissue became completely necrotized. 3 weeks and 80 days after PDT, the tumor bed was still covered with necrotic debris. It is concluded that in PDT treated tumors, the capillary endothelium will be primarily damaged while destruction of cancer cells be mainly caused by structural and functional changes in microcirculation.