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 upp er and lower GI tract to illustrate the ability to detect early-stage lesio ns that were not observable with white light endoscopy or those in which th e assessment of the stage or extension of the lesion were equivocal. Methods: A new fluorescence imaging system was used in which blue light exc ites the naturally-occurring fluorescence of tissues (autofluorescence). Th e 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 surroundi ng tissue. This system was evaluated in patients at 4 participating institu tions, concurrently with standard white light endoscopy, with or without dy e staining. Results: Selected cases are presented in which fluorescence imaging identif ied specific lesions including focal high-grade dysplasia in Barrett's muco se, signet ring carcinoma of the stomach, and flat adenoma in the colon. Conclusions: The capability of autofluorescence endoscopy to detect the pre sence and extent of occult malignant and premalignant GI lesions has been d emonstrated. The future development and evaluation of this technology are d iscussed.