[Fluorescence diagnosis of porphyrin-marked urothelial tumors. Status of experimental development].

On the basis of selective storage of fluorescing hematoporphyrin derivative (HpD) in tumors, a method has been developed that enables the endoscopic detection of early-stage cancer by monitoring fluorescent images. The contrast-reducing portion of the superposed tissue autofluorescence is suppressed by the use of two-wavelength excitation and subsequent image processing in realtime. The amount of photosensitizing HpD necessary for diagnostic purposes is considerably reduced by means of sensitive detection devices. A clear distinction between benign and malignant bladder tissue seems possible according to the results of animal studies.