Autofluorescence endoscopy: feasibility of detection of GI neoplasms unapparent to white light endoscopy with an evolving technology

Background: Case studies are presented of fluorescence endoscopy in the upper and lower GI tract to illustrate the ability to detect early-stage lesions that were not observable with white light endoscopy or those in which the assessment of the stage or extension of the lesion were equivocal. Methods: A new fluorescence imaging system was used in which blue light excites the naturally-occurring fluorescence of tissues (autofluorescence). The system produces real-time, false-color images that combine green and red fluorescence intensities. In general, abnormal lesions are seen to have an increase in the red-to-green fluorescence intensity compared with surrounding tissue. This system was evaluated in patients at 4 participating institutions, concurrently with standard white light endoscopy, with or without dye staining. Results: Selected cases are presented in which fluorescence imaging identified specific lesions including focal high-grade dysplasia in Barrett's mucose, signet ring carcinoma of the stomach, and flat adenoma in the colon. Conclusions: The capability of autofluorescence endoscopy to detect the presence and extent of occult malignant and premalignant GI lesions has been demonstrated. The future development and evaluation of this technology are discussed.