[Diagnosis and treatment of bladder tumors by photodynamic therapy]

Experimental results and clinical trials showed that bladder tumours Tis and pT1a can be diagnosed by photodynamic diagnosis and treated by photodynamic therapy. These photochemical methods are based on a selective photosensitizer uptake in the tumour tissue. After subsequent irradiation, these tissues emit a fluorescence (diagnosis) or can be destroyed by chemically induced oxidative compounds (treatment). Hematoporphyrin derivative and its oligomeric part have been the light-sensitizing drugs the most commonly studied. Interest has now shifted to 5-aminolevulinic acid, or its hexylester form, inducing protoporphyrin IX which shows better tumour localising properties and could avoid side effects. While photodynamic treatment is still an experimental modality, photodynamic diagnosis could achieve a more accurate detection of occult dysplasia compared to white light cystoscopy.