Low-dose topical administration of delta-ALA provides ablation of low-grade dysplasia in the range obtained with oral delta-ALA. In addition, it is safe and well tolerated. Since, however, topical administration of delta-ALA is not able to consistently eradicate Barrett's esophagus, alternative methods will have to be developed.

No 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.

No abstract