<title>Endoscopic detection of early malignancies in the upper gastrointestinal tract using laser-induced fluorescence imaging</title>

Abstract

Fluorescence images were recorded simultaneously with white light images to detect dysplasia or early malignancies during regular endoscopy of the upper gastrointestinal tract, after topical administration of 5-aminolaevulinic acid. Biopsies were taken at locations where fluorescence intensities were high compared with the mean fluorescence intensity of the image. Prompt and delayed fluorescence spectra of biopsies were subsequently recorded ex vivo, and normalised fluorescence intensities of Protoporphyrin IX derived from these spectra were compared with routine histology. In contrast to routine endoscopy, one early carcinoma and one signet-ring carcinoma were found in the stomach, and malignancies in a duodenal polyp. In addition, intestinal metaplasia could be visualised in the stomach of two patients, which had not been detected in biopsies taken prior to fluorescence endoscopy.

Optical Imaging Modalities for Biomedical Applications

“…Fluorescence imaging helps to enhance the visual distinction between cancerous and healthy tissue, which may not always be visible or easy to delineate with conventional white light illumination. Cancerous tissue typically reveals itself by emitting an increased amount of fluorescent light compared to healthy tissue [88]; thus, these areas are best served as biopsy sites [89]. Depending on the fluorophore used, cancerous or healthy tissue fluorescence may also be manifested by different colors.…”