AN ENDOSCOPIC FLUORESCENCE IMAGING SYSTEM FOR SIMULTANEOUS VISUAL EXAMINATION AND PHOTODETECTION OF CANCERS

We describe the design and performance tested during six years of clinical trials of a fluorescence endoscope for the detection and delineation of cancers in several hollow organs. The apparatus is based on the imaging of the laser-induced fluorescence that differs between a tumor and its surrounding normal tissue. The tests are carried out in the upper aerodigestive tract, the tracheobronchial tree, the esophagus, and the colon. In the three former cases an exogenous dye is used (Photofrin II), whereas in the latter case fluorescein molecules conjugated with monoclonal antibodies directed against carcinoembryonic antigen are injected. The decrease of native tissue autofluorescence observed in early cancers is also used for detecting lesions in the tracheobronchial tree. The fluorescence contrast between the tumor and surrounding normal tissue is enhanced by real time image processing. This is done by simultaneously recording the fluorescenceimage in two spectral domains, after which these two images are digitized and manipulated with a mathematical operator (look-up table) at video frequency. Moreover, the device that is described below allows for an immediate observation of the endoscopic area under white light illumination during fluorescence detection in order to localize the origin of the “positive” fluorescence signals. Typical results obtained in the tracheobronchial tree and in the colon are presented and the sources of false positives and false negatives are evaluated in terms of the fluorescent dye, tissue optical properties, and illumination optics.

[1]  R. Alfano,et al.  Optical spectroscopic diagnosis of cancer and normal breast tissues , 1989 .

[2]  D. Jocham,et al.  A FLUORESCENCE IMAGING DEVICE FOR ENDOSCOPIC DETECTION OF EARLY STAGE CANCER – INSTRUMENTAL and EXPERIMENTAL STUDIES , 1987, Photochemistry and photobiology.

[3]  Uwe Sukowski,et al.  Imaging of superficially growing tumors by delayed observation of laser-induced fluorescence , 1993, Photonics West - Lasers and Applications in Science and Engineering.

[4]  Thomas S. Mang,et al.  Fiber optic fluorescence detection of low-level porphyrin concentrations in preclinical and clinical studies , 1990, Photonics West - Lasers and Applications in Science and Engineering.

[5]  R. Alfano,et al.  Laser induced fluorescence spectroscopy from native cancerous and normal tissue , 1984 .

[6]  A E Profio,et al.  Digital background subtraction for fluorescence imaging. , 1986, Medical physics.

[7]  Sidney Udenfriend,et al.  Fluorescence assay in biology and medicine , 1962 .

[8]  Christian D. Depeursinge,et al.  Photodetection of early cancer by laser-induced fluorescence of a tumor-selective dye: apparatus design and realization , 1990, Photonics West - Lasers and Applications in Science and Engineering.

[9]  Patrice Jichlinski,et al.  Fluorescence excitation and emission spectra of ALA-induced protoporphyrin IX in normal and tumoral tissue of the human bladder , 1995, Other Conferences.

[10]  Christian D. Depeursinge,et al.  Photodetection of early cancer in the upper aerodigestive tract and the bronchi using photofrin II and colorectal adenocarcinoma with fluoresceinated monoclonal antibodies , 1991, MedTech.

[11]  R. Rava,et al.  SPECTROSCOPIC DIAGNOSIS OF COLONIC DYSPLASIA , 1991, Photochemistry and photobiology.

[12]  J C Kennedy,et al.  Endogenous protoporphyrin IX, a clinically useful photosensitizer for photodynamic therapy. , 1992, Journal of photochemistry and photobiology. B, Biology.

[13]  D. E. Pearson,et al.  Transmission and display of pictorial information , 1975 .

[14]  S. Svanberg,et al.  Medical diagnostic system based on simultaneous multispectral fluorescence imaging. , 1994, Applied optics.

[15]  Hubert van den Bergh,et al.  Clinical comparison of the pharmacokinetics of m-THPC and Photofrin II as observed by light-induced fluorescence , 1994, Other Conferences.