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4 January 1995 Bladder tissue diagnostics utilizing Protoporphyrin IX fluorescence detection
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Proceedings Volume 2324, Optical Biopsy and Fluorescence Spectroscopy and Imaging; (1995)
Event: International Symposium on Biomedical Optics Europe '94, 1994, Lille, France
Instillation of a solution of 5-aminolevulinic acid (5-ALA) into the urinary bladder leads to a tumorselective accumulation of fluorescing Protoporphyrin IX (PpIX) within hours. Upon fluorescence excitation using a Kr+- laser, cystoscopy provides high contrast images even of early stage tumors, that are invisible or hardly detectable by routine white light cystoscopy. Fluorescence can simply be judged by naked eyes or recorded with a target integrating camera in real color. Histological and fluorescence data of 91 patients were evaluated statistically, showing a sensitivity of 97% and a specificity of 68% for the detection of dysplastic lesions or malignant tumors. The detectability of a sufficient fluorescence contrast of suspicious versus normal tissue is not affected significantly by either short incubation times of less than 1 hour or prolonged retention times without 5-ALA in the instillation liquid of up to about 6 hours. The fluorescence intensity detected from the tissue surface is not only dependent on PpIX concentration. The additional influence of optical parameters of tissue and fluorochrome distribution on the fluorescence signal was determined using Monte Carlo computer simulations. Results show that 5-ALA induced fluorochrome detection is superior to the detection of fluorochromes that do not exclusively stain the epithelium. Using the ratio of fluorescence intensity to backscattered excitation light corrects for geometrical and absorption effects but would introduce a dependence on the scattering coefficient.
© (1995) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Herbert G. Stepp, Reinhold Baumgartner, Wolfgang Beyer, Ruth Knuechel, Kai Rick, Pia Steinbach, and M. Kriegmair "Bladder tissue diagnostics utilizing Protoporphyrin IX fluorescence detection", Proc. SPIE 2324, Optical Biopsy and Fluorescence Spectroscopy and Imaging, (4 January 1995);

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