Download Endoscopic Image Conference

2009년 3월 23일
Jun Haeng Lee, Joo Yong Cho, Myung Gyu Choi,
Joo Sung Kim, Kee Don Choi, Yong Chan Lee,
Jae Young Jang, Hoon Jai Chun, and Sang Yong Seol
Gut and Liver 2008;2:174-179.
Introduction
• Gastric cancer is one of the leading causes of cancer death
in the world
• Treatment of gastric cancer
– Surgery vs. Endoscopic resection
• For successful endoscopic submucosal dissection?
– Clear delineation of lateral margin
• Clear delineation of lateral margin
A
Autofluorescence imaging
• For detection of premalignant lesion
• For clear delineation of lateral margin
Photodiagnostic Techniques
• Detecting the very earliest mucosal changes at the
microstructural, biochemical and molecular levels by
detecting the relative changes in the way light interacts
with tissue along the disease transformation pathway
Tissue Autofluorescence
• Illuminated with ultraviolet (UV) or short
wavelength visible light from a laser source or
a filtered lamp, fluorescence light of a longer
wavelength is emitted
Tissue Autofluorescence
• Fluorophores:
– connective matrix (collagen, elastin),
– cellular metabolic coenzymes (NADH, FAD, FMN)
– Aromatic amino acids (tryptophan, tyrosine, phenylalanine)
– porphyrins
– lipopigments (lipofuscin, ceroids)
• Chromophores:
– molecules intrinsic to tissues that absorb light without re-emission of
fluorescence
– hemoglobin
Some Known Endogenous Fluorophores and
Wavelengths of Their Excitation and Emission Maxima
Tissue
fluorophore
Biological source
Wavelength of
maximum fluorescence
excitation (nm)
Wavelength of
maximum fluorescence
emission (nm)
Tryptophan
Amino acids
280
350
Collagen
Connective tissues
330
390
Elastin
Connective tissues
350
420
NADH
Metabolic cofactor
340
450
FAD
Metabolic cofactor
450
515
Porphyrins
By-product of heme biosynthesis;
bacterial fauna
405
635
Ceroid, lipofuscin
Lipopigment granules;
age related;
lipid oxidation products
340-395
430-460, 540,-645
Digestive Endoscopy 2003;15:153-173.
Autofluorescence and Reflectance Imaging (AFI)
• Instruments:
– Videoendoscope (XGIF-Q240FY; Olympus Medical Systems Corp)
– Two charged coupled devices (CCD)
– Barrier filter (490-625 nm)
• Mode:
– White light (WL)
– AF
• Autofluorescence (395-475 nm)
• Green reflectance (540-560 nm):
– Reduce the confounding effects of inflammation
• Red reflectance (600-620 nm):
– Overall brightness and surface geometry
Diagram of the AFI videoendoscopy system
Excitation light for inducing AF (395-475 nm),
G’-light (550 nm), R’-light (610 nm)
Gastrointest Endosc 2005;62:521-528.
Auto-fluorescence
Green reflectance
Red reflectance
AFI image
Normal
mucosa
Tumor
Vessel or
inflammation
(Hb)
Gastrointest Endosc 2005;62:521-528.
MATERIALS AND METHODS
• Patients:
– Multi-center prospective study in Korea (9 university)
– December 2005 and July 2006
– 98 patients
– Gastric adenoma and EGC
• Endoscopic evaluation
– Location, size, diagnosis, and macroscopic shape of the
lesions
– WLE, AFI, and chromoendoscopy
– Two types by the macroscopic shape
• Elevated type and flat or depressed type
MATERIALS AND METHODS
• Resection of the tumors
– A total of 102 lesions in 98 patients (73 men, 25 women)
– 94 lesions
• 86 lesions: endoscopical removal
• 8 lesions: surgery
• EGC: 48
• Adenoma: 54
– The estimated size in endoscopy (WLE and AFI)
– The length of the tumor in pathology specimen
– The difference: < 3mmlength was considered correct
Poor Diff Adenoca,
Stomach
Low Grade Dysplasia, Stomach
Low Gr Dysplasia,
Stomach
Well Diff Adenoca,
Stomach
Results
•
Size estimation:
– WLE: 53.9% (55/102)
– AFI: 54.7% (47/86)
•
In the 86
– Pathologic specimen: 1.81±1.21 cm
– WLE: 1.76±0.88 cm
– AFI: 2.00±0.99 cm (p＜0.01, paired t-test).
•
Estimated length was shorter than pathologic length in 31.4% for WLE
and 22.1% for AFI.
•
In the 29 cases of flat or depressed lesions:
– Pathologic specimen: 1.95±1.45 cm
– WLE: 1.69±0.69 cm
– AFI: 1.98±0.83 cm (p＜0.01, paired t-test).
Conclusion
• WLE tends to underestimate the size of
EGCs, whereas AFI tends to overestimate
their size.