Ralph Kiesslich and colleagues, based in Mainz, Germany have assessed the diagnostic potential of a newly developed confocal laser endoscopy system.
The group looked at the ability of this system, which is able to produce subsurface images of living cells in colonic tissue in vivo, to predict histology in screening for colorectal cancer.
A total of 27 patients were chosen to undergo colonoscopy with the confocal endoscope using acriflavine hydrochloride or fluorescein sodium with blue laser illumination.
Furthermore, 42 patients underwent colonoscopy with this system using fluorescein sodium only.
The researchers examined standardized locations and circumscript lesions using confocal imaging before taking biopsy specimens.
Confocal images were graded according to cellular and vascular changes and then correlated with conventional histology in a prospective and blinded fashion.
The researchers found that acriflavine hydrochloride and fluorescein sodium both yielded high-quality images.
|Confocal laser endoscopy predicts the presence of neoplastic changes with high accuracy
Whilst acriflavine was found to strongly label the more superficial epithelial cells, fluorescein sodium was able to provide deeper imaging into the lamina propria.
Hence the group used fluorescein sodium for the prospective component of the study in which 13,020 confocal images from 390 different locations were compared with histologic data from 1038 biopsy specimens.
The researchers were able to obtain detailed analysis of cellular structures from the subsurface analysis during confocal laser endoscopy.
The presence of neoplastic changes could be predicted with high accuracy (sensitivity, 97.4%; specificity, 99.4%; accuracy, 99.2%).
The group concluded that confocal laser endoscopy is a diagnostic tool that can be used to analyze living cells during colonoscopy, thereby enabling virtual histology of neoplastic changes with high accuracy.
Dr Kiesslich commented, "These newly discovered diagnostic possibilities may be of crucial importance in clinical practice and lead to an optimized rapid diagnosis of neoplastic changes during ongoing colonoscopy".