[Experimental investigations and clinical use of photodynamic therapy (PDT) in the Rudolf Foundation Hospital]

This article addresses experimental investigations and the clinical use of PDT in the Rudolfstiftung Hospital, Vienna. We investigated mesotetrahydroxyphenylchlorine (mTHPC) and the photosensitizer hematoporphyrin derivative alone or in combination to prove photodynamic antibacterial effects on Staphylococcus aureus (wild type). mTHPC showed antibacterial toxicity in the dark; hematoporphyrin derivative showed suppressive growth effects only after white-light illumination. Photodynamic activity by the combination of both dyes was obtained in a roughly additive manner. Furthermore, we observed the development of resistance of erythromycin after the illumination procedure with hematoporphyrin derivative. Wild-type S. aureus developed no resistance to the other antibiotics tested. Furthermore, long-term follow-up examinations proved mTHPC-mediated PDT as a possible adjuvant intraoperative therapy in cases of relapses of gynecologic carcinomas. PDT is a tissue-selective and simple intervention. It shows few side effects, and, therefore, it reduces the overall burden of tumor patients. In another clinical investigation, we used 5-aminolevulinic acid-based PDT to treat intraepithelial neoplasia and human papillomavirus of the uterine cervix. 33 of 38 (86,8%) patients with superficial cervical intraepithelial neoplasia grades I and II were treated successfully with PDT. Eradication of human papillomavirus infections was successfully performed in 80% of the cases.