Z Gastroenterol 2011; 49 - P070
DOI: 10.1055/s-0031-1285342

Normalized autofluorescence imaging diagnostics in upper GI tract: a new method to improve specificity in neoplasia detection

E Krauss 1, A Douplik 2, H Albrecht 1, A Agaimy 3, R Hohenstein 2, M Neurath 1, J Mudter 1
  • 1Department of Medicine 1, University of Erlangen-Nuremberg, Erlangen, Germany
  • 2Clinical Photonics Lab, Erlangen Graduate School in Advanced Optical Technologies (SAOT), Erlangen, Germany
  • 3Institute of Pathology, University of Erlangen-Nuremberg, Erlangen, Germany

Background & aims: To date the autofluorescence imaging (AFI) diagnostics has been successfully applied as adjuvant imaging technique in combination with conventional or high-resolution endoscopic surveillance in the colon and respiratory tract to assist early discover of dysplastic lesions, biopsy guidance and microsurgery navigation. This single-center feasibility study was performed to improve the AFI surveillance examining the upper GI tract by applying a new method of normalized AFI (NAFI) obtained via tri-modal imaging.

Materials and methods: Prospectively, 18 patients with suspected esophagus or stomach cancer undergoing EGD were enrolled between February and May 2010. After endoscopy each patient was assigned into the two groups: (1) non-cancer group, (2) cancer group (squamous cell carcinoma of esophagus and gastric adenocarcinoma).

The diagnoses were made by correlation of patient's medical history, endoscopy, and histological results of targeted biopsy specimens, taken from suspicious areas. EGDs were first performed using video white light endoscopy (Video-WLE), followed by AFI EGD. The targeted biopsy samples were taken at the end of the procedure under AFI examination from the areas displayed as abnormal as well as from adjacent normal mucosa.

Results: Among patients inspected with NAFI (12) all four neoplastic lesions were primarily detected. Subsequent WLE or NBI detected no additional neoplasia. In case of mucosal inflammation, AFI showed wide patchy redness and rarely displayed it precisely. The NAFI didn't differentiate inflamed from normal tissue in the majority of cases. But in tumorous mucosa, where the AFI showed only redness, the NAFI contoured the cancer areas, which were then confirmed by the histology of biopsy specimens. The NAFI showed 69% specificity and 88% sensitivity for cancer group.

Conclusions: Measuring the NAFI instead of the AFI was found improving the specificity of cancer diagnostics by 19%. Future randomized cross-over studies establishing feasibility of NAFI in setting of high-resolution video endoscopy, especially performed in a non-expert setting, have to clarify the true diagnostic potential of this new method for the detection of cancer in upper GI tract.