Light-induced Fluorescence Endoscopy Research Articles

Cytological findings of pre-invasive bronchial lesions detected by light-induced fluorescence endoscopy in a lung cancer screening system

Lung cancer is a global epidemic and the number one cause of death among all cancers, with a very high morbidity. A new strategy for the treatment of lung cancer is the detection and eradication of pre-invasive bronchial lesions before they become invasive carcinomas. We conducted a detailed investigation into the use of fluorescence bronchoscopy in the detection of pre-invasive bronchial lesions in patients with sputum cytology suspicious or positive for malignancy. We also studied the distinctive cytological findings in the sputum specimens corresponding to the pre-invasive bronchial lesions. Sputum examinations were performed by mass screening a high-risk group of participants. From 1997 to 1999, 61 participants with sputum cytology suspicious or positive for malignancy were referred to our institute, and were examined with both white-light and fluorescence bronchoscopy. For the cytological findings, the collection of sputum was performed in the early morning. Conventional white-light examinations were first performed, and areas with abnormal findings were recorded for subsequent biopsy. Fluorescence bronchoscopy examinations were then carried out. Biopsy specimens for a pathological examination were taken from all the suspicious or abnormal areas discovered by the white-light bronchoscopy, or fluorescence bronchoscopy examination, or both. The laser-induced fluorescence bronchoscopic examination showed a high sensitivity for invasive carcinoma, carcinoma in situ, as well as severe, moderate, and mild dysplasia. In the sputum cytological findings, a thickened cytoplasm and slight hyperchromasia were frequently observed in the mild dysplasias compared with the squamous cells without atypia. Hyperchromasia and an Orange G (OG)-philic cytoplasm of squamous cells were frequently observed in the moderate compared with the mild dysplasias. A thickened cytoplasm, a nuclear pleomorphism, a thickened nuclear rim, a coarse chromatin, an uneven chromatin distribution, and an OG-philic cytoplasm were frequently observed in the carcinomas in situ and severe dysplasias compared with the moderate dysplasias. We found that the use of fluorescence bronchoscopy in addition to conventional white-light examination can enhance the detection and localization of pre-invasive bronchial lesions in patients with sputum cytology suspicious or positive for malignancy. Sputum cytology is therefore a potential approach to diagnosing pre-invasive bronchial lesions.

Detection of Pre-Invasive Lung Cancer: Technical Aspects of the LIFE Project

Lung cancer is the leading cause of cancer deaths in both men and women in the United States. The LIFE (Light Induced Fluorescence Endoscopy) Project was initiated at the University of North Carolina Medical Center in November, 1999, for the dual purposes of (1) detecting pre-invasive lung cancer in high-risk patients and (2) studying the molecular biology of pre-invasive lesions of the bronchus for possible development of molecular biomarkers. Of the 47 patients enrolled, all were current or former tobacco smokers, except for 1. Fluorescence endoscopy was utilized, in addition to white light bronchoscopy, to increase the detection of intraepithelial lesions. Adjacent biopsies were submitted for permanent and frozen sections, respectively, from four predetermined sites as well as from any abnormal areas. The snap-frozen specimens were cryostat sectioned, and the mucosal epithelial cells laser capture microdissected for DNA analysis. The great majority of specimens yielded sufficiently abundant and intact DNA to accomplish the molecular objectives. Histologic concordance of adjacent permanent and frozen sections was equivalent to the concordance of adjacent permanent sections, suggesting that frozen section diagnosis was adequate for the research purpose of correlating histology with molecular analysis.

A randomized crossover study comparing light-induced fluorescence endoscopy with standard videoendoscopy for the detection of early neoplasia in Barrett's esophagus

Light-induced fluorescence endoscopy (LIFE) may improve the detection of high-grade dysplasia (HGD) and early stage cancer (EC) in Barrett's esophagus (BE). The aim of this study was to compare LIFE with standard endoscopy (SE) in a randomized crossover study. Fifty patients with BE underwent SE and LIFE in a randomized sequence (4 to 6-week interval between procedures). The two procedures were performed by two different endoscopists who were blinded to the findings of the other examination. Targeted biopsy specimens were taken from detected lesions, followed by random biopsy specimens with a 2-cm interval, 4-quadrant protocol. Biopsy specimens were routinely evaluated and subsequently reviewed by a single, blinded expert GI pathologist. Targeted biopsy specimens had a sensitivity for the diagnosis of HGD/EC of 62% (8/13) for both techniques. The overall sensitivity (all biopsy specimens) was 85% for SE and 69% for LIFE (p = 0.69). All targeted biopsy specimens had a positive predictive value (PPV) for HGD/EC of 41% for SE and 28% for LIFE (p = 0.40); autofluorescence-targeted biopsy specimens had a PPV of 13%. False-positive lesions had a significantly higher rate of acute inflammation than random biopsy specimens. In this study, LIFE did not improve the detection of HGD or EC in patients with BE compared with SE.

Fluorescence Bronchoscopy for Selection of Surgical Procedure in Patients With Early Staged Endobronchial Carcinoma

It is sometimes difficult to determine the extent of resection in patients with endobronchial carcinoma because preoperative white-light bronchoscopic (WLB) examination is not sensitive enough to examine the extent fully. Light-Induced Fluorescence Endoscopy (LIFE) is recognized as a useful modality for the diagnosis of early staged bronchial carcinoma, but there have been no reports of its significance in surgical treatment. We have studied the influence of LIFE upon the selection of surgical procedures or other treatments in patients with endobronchial carcinoma preoperatively. Conventional WLB and LIFE were performed within 7 days of operation. Biopsy specimens were taken from the marginal regions of the areas that were suspicious for malignancy on LIFE examination and WLB. We decided the resection line before operation and kept the resected central margin 1 cm apart from the area revealed as suspicious by LIFE. From January 1999 to March 2003, 75 patients underwent LIFE. LIFE was performed to decide the surgical procedures for 12 patients (16.0%). Surgical therapy was performed in 8 (66.7%). LIFE findings dramatically changed the surgical procedures for 3 patients, lobectomy changed to sleeve lobectomy in 2 and laser therapy to segmentectomy in 1. LIFE revealed larger abnormal areas of bronchial cancer compared to WLB in 7 (58.3%). Conversely, WLB overestimated the extent of abnormal area in 1 (8.3%). WLB revealed the same cancer area as LIFE in 4. In all patients, the resected bronchial margins were cancer free intraoperatively and postoperatively. LIFE can be more sensitive than WLB and be more beneficial for judging the extent of neoplastic bronchial changes for some patients. LIFE may be a useful modality for the preoperative selection of surgical procedures, especially whether sleeve resection is needed or not, for some centrally located superficial endobronchial carcinoma.

Effective detection of bronchial preinvasive lesions by a new autofluorescence imaging bronchovideoscope system

Autofluorescence bronchoscopy is an important tool for the early detection of preinvasive bronchial lesions. However, autofluorescence bronchoscopy has difficulty distinguishing between preinvasive lesions and other benign epithelial changes. A new autofluorescence imaging bronchovideoscope system (AFI) comprises three signals, including an autofluorescence (460-690 nm) on excitation blue light (395-445 nm) and two different bands of reflected light: G' (550 nm) and R' (610 nm). We hypothesized that color analyses of these three wave lengths would improve our ability to differentiate between inflammation and preinvasive lesions. In order to prove this hypothesis and to evaluate the efficacy of AFI for detecting preinvasive lesions, we conducted a prospective study. A total of 32 patients with suspected or known lung cancer were entered into this study. Conventional white light bronchovideoscopy (WLB) and light induced fluorescence endoscopy (LIFE) were performed prior to using AFI. WLB and LIFE detected 62 lesions, including lung cancers (n=2), squamous dysplasias (n=30), and bronchitis (n=30). By utilizing AFI, 24 dysplasias and 2 cancer lesions were magenta in color, while 25 bronchitis lesions were blue. The sensitivities of detecting dysplasia by LIFE and AFI were 96.7% and 80%, respectively. The specificity of AFI (83.3%) was significantly higher than that of LIFE (36.6%) (p=0.0005). We conclude that AFI appears to represent a significant advance in distinguishing preinvasive and malignant lesions from bronchitis or hyperplasia under circumstances where LIFE would identify these all as abnormal lesions.

Diagnostic performance of light-induced fluorescence endoscopy for gastric neoplasms.

Malignant tumors generate autofluorescent patterns that differ from those of normal tissue. However, whether autofluorescent diagnosis could be genuinely useful in screening for gastric neoplasms has not been well investigated in clinical practice. Accordingly, we retrospectively studied our experience with this diagnostic technique for various gastric lesions and assessed its diagnostic utility. Autofluorescence diagnosis of 109 gastric lesions in 79 patients was done, without knowledge of the diagnosis by conventional white light endoscopy, retrospectively and independently by three endoscopists with 6 years', two years' and no experience of the technique. After examination of the interobserver bias in the assessment of autofluorescent pseudocolor in light-induced fluorescence endoscopy (LIFE), the relationship between pseudocolor and characteristics of gastric lesions (including histology, macroscopic type, and depth of invasion) were investigated. The kappa statistic for agreement in pseudocolor diagnosis between the three endoscopists was 0.71. The assessment of pseudocolor by all of the observers was in agreement in 67 of the total of 109 lesions (61.5 %). Experience with the LIFE technique did not improve the accuracy of pseudocolor determination. All of the cancers, 87.5 % of the adenomas, and 50.9 % of the benign lesions were recognized as having an abnormal autofluorescent image. None of the gastric cancers and 49.1 % of the benign lesions were evaluated as having a normal autofluorescence image. The histopathological and macroscopic types of tumors and their depths of invasion were not reflected in the autofluorescence diagnosis. LIFE provided a sensitivity of 96.4 % and specificity of 49.1 %, suggesting that this technique has limited clinical utility, regardless of the merits of acceptable interobserver bias and lack of necessity for experience with this technique.

M2A Wireless Capsule Endoscopy Versus Enteroclysis; A Prospective Study in 68 Patients with Suspected Small Bowel Disease

M2A Wireless Capsule Endoscopy Versus Enteroclysis; A Prospective Study in 68 Patients with Suspected Small Bowel Disease Periklis Apostolopoulos, Eleftheria Giannakoulopoulou, Ioannis S. Papanikolaou, Georgios Alexandrakis, X. Papacharalampous, Chrissostomos Kalantzis, Peter Gabriel, Nikolaos Kalantzis Background and Study Aims: To compare the diagnostic yield of wireless capsule endoscopy (WCE) and enteroclysis (EC) in suspected small bowel (SB) disease. Patients and Methods: Sixty-eight patients (31 men, 37 women; mean age:59+/ 18 years, range:17-78 years) with suspected SB disease (obscure GI bleeding: 47pts, unexplained chronic diarrhea: 15pts, miscellaneous: 6pts) were prospectively studied. EC followed by WCE was performed in all patients; gastroenterologists were blinded to the results of EC at the time of interpretation of the WCE video. Both WCE and radiological findings were characterized as specific and non-specific, if the patients signs and symptoms could be or couldn’t be sufficiently attributed to them, respectively. Chi-square test and Fisher exact test were used for statistical analysis. Results: Abnormal findings were documented in 14/68pts using EC and in 53/68pts using WCE (20.6% vs. 77.9% respectively, p=0.000). For the diagnostic yield of WCE vs. enteroclysis in demonstrating specific abnormal findings, WCE was also more effective (47% vs. 14.7%, p=0.0000). Moreover, WCE is more effective in revealing abnormal findings in obscure GI bleeding (76.6% vs. 10.6% of enteroclysis, p=0.0000). Specific findings in this group were 42.5% and 6.4% respectively (p=0.0000). In 15 pts evaluated for unexplained chronic diarrhoea, abnormal findings were detected in 10/15 (66.6%) byWCE and in 4/15(26.6%) by EC (p<0.05). It should be pointed out that, WCE was able to diagnose Crohn’s disease of the SB, undetected by conventional diagnostic methods in 9/68 pts (5pts were evaluated for obscure GI bleeding and 4pts for unexplained chronic diarrhoea). Conclusions: The present study suggests that in certain patient groups with suspected SB disorders, WCE has a superior diagnostic yield compared to EC. Its usefulness is undoubted for the evaluation of patients with obscure GI bleeding and chronic unexplained diarrhoea. WCE complements the traditional work-up in patients with suspected SB disease, holding the promise that fewer patients with SB disorders will remain undiagnosed, especially as it concerns SB Crohn’s disease. *M1704 A Novel Autofluorlesence Imaging Videoendoscopy System for Diagnosis of Esophago-Gastric Cancers Noriya Uedo, Hiroyasu Iishi, Masaharu Tatsuta, Yoshiyuki Hukushima, Koji Higashino, Ryu Ishihara, Hiroyuki Narahara An autofluorescence endoscopy sytem produces real-time pseudo-color images that specify lesions including gastrointestinal malignancies and it has possibility to detect early-stage lesions that were difficult to observe with conventional white light endoscopy. We have investigated an effectiveness of light-induced fluorescence endoscopy system (LIFE) on screening for superficial esophageal squamous cell carcinomas (SESCC) and on diagnosis of early gastric adenocarcinoma (EGA). However, LIFE used fiber-optic scope in its system, so its image quality and handleability were not enough for general clinical usage. Therefore we are developing novel autofluorlesence imaging videoendoscopy system (AFI, manufactured by Olympus Optical Co., Ltd.). In this study, we evaluated its feasibility for clinical application. AFI equipped two CCDs; one for white-light observation and another for autofluorescence observation, on the tip of the scope and they could be easily switched by small push button on the scope handle. AFI compose real-time images from pseudocolors of autofluorescence (excitation: 395475 nm, detection: 490-625 nm), red reflection (R’: 600-620) and green reflection (G’: 540-560) by sequentialmethod in order to represent clear image profiles and to distinguish reduction of autofluorescence by tumor from that by hemoglobin. Assessing the image resolutions of AFI and LIFE-GI by OMC resolution chart (lines/mm at 5 mm distance), AFI has higher resolution than LIFE-GI at both whight light (16 and six) and autofluorescence (seven and five) observation. We studied five patients with SESCC and 12 patients with EGA by AFI. For the esophagus, SESCC were observed as well contrasted magenta colored areas in green normal mucosa (Figure). We found a small secondary primary lesion in a patient with SESCCat autofluoresence observation. For the stomach, EGA exist in atrophic mucosa were observed as magenta colored areas in bright green background mucosa, while EGA exist in fundic mucosa were observed as green areas in magenta background mucosa. Non-specific inflammations or patchy atrophic changes often contaminate detection of tumor or assessment of tumor extension. Image quality of AFI videoendoscopy system at both white-light and autofluorescence observations was feasible for evaluating its clinical usefulness for SESCC. The system will be tuned-up to improve specificity for diagnosis of EGA.

A Novel Autofluorlesence Imaging Videoendoscopy System for Diagnosis of Esophago-Gastric Cancers

An autofluorescence endoscopy sytem produces real-time pseudo-color images that specify lesions including gastrointestinal malignancies and it has possibility to detect early-stage lesions that were difficult to observe with conventional white light endoscopy. We have investigated an effectiveness of light-induced fluorescence endoscopy system (LIFE) on screening for superficial esophageal squamous cell carcinomas (SESCC) and on diagnosis of early gastric adenocarcinoma (EGA). However, LIFE used fiber-optic scope in its system, so its image quality and handleability were not enough for general clinical usage. Therefore we are developing novel autofluorlesence imaging videoendoscopy system (AFI, manufactured by Olympus Optical Co., Ltd.). In this study, we evaluated its feasibility for clinical application. AFI equipped two CCDs; one for white-light observation and another for autofluorescence observation, on the tip of the scope and they could be easily switched by small push button on the scope handle. AFI compose real-time images from pseudocolors of autofluorescence (excitation: 395-475 nm, detection: 490-625 nm), red reflection (R': 600-620) and green reflection (G': 540-560) by sequential method in order to represent clear image profiles and to distinguish reduction of autofluorescence by tumor from that by hemoglobin. Assessing the image resolutions of AFI and LIFE-GI by OMC resolution chart (lines/mm at 5 mm distance), AFI has higher resolution than LIFE-GI at both whight light (16 and six) and autofluorescence (seven and five) observation. We studied five patients with SESCC and 12 patients with EGA by AFI. For the esophagus, SESCC were observed as well contrasted magenta colored areas in green normal mucosa (Figure). We found a small secondary primary lesion in a patient with SESCC at autofluoresence observation. For the stomach, EGA exist in atrophic mucosa were observed as magenta colored areas in bright green background mucosa, while EGA exist in fundic mucosa were observed as green areas in magenta background mucosa. Non-specific inflammations or patchy atrophic changes often contaminate detection of tumor or assessment of tumor extension. Image quality of AFI videoendoscopy system at both white-light and autofluorescence observations was feasible for evaluating its clinical usefulness for SESCC. The system will be tuned-up to improve specificity for diagnosis of EGA.

A randomized cross-over study comparing light-induced fluorescence endoscopy (LIFE) with standard endoscopy for detection of early neoplasia in Barrett's esophagus (BE)

A randomized cross-over study comparing light-induced fluorescence endoscopy (LIFE) with standard endoscopy for detection of early neoplasia in Barrett's esophagus (BE)

Subepithelial vascular patterns in bronchial dysplasias using a high magnification bronchovideoscope

Background: We have developed a method of high magnification bronchovideoscopy that enables improved observation of subepithelial vascular patterns of the bronchial mucosa. A study was undertaken to investigate the value...

Diagnostic potential of light-induced fluorescence endoscopy in the colon

Diagnostic potential of light-induced fluorescence endoscopy in the colon

Is the light induced fluorescence endoscopy (LIFE-GI) possible to differentially diagnose early gastric cancer and adenoma?

Is the light induced fluorescence endoscopy (LIFE-GI) possible to differentially diagnose early gastric cancer and adenoma?

Detection of early gastric cancer by a real-time autofluorescence imaging system

A light-induced fluorescence endoscopy in the gastrointestinal tract system was used in 52 patients with 54 lesions (33 early gastric cancers, 21 benign lesions) to assess its ability to detect early gastric cancer. Comparing the images with the histological findings, 21 of the 33 carcinomas appeared dark red, ten had a mixed pattern of dark red and white, and two could not be detected. Of the 21 benign lesions, 18 appeared light blue, as do normal mucosa, with this system. In 85% of the cancer lesions (28/33), cancer extension was correctly detected. The sensitivity and specificity were 94 and 86%, respectively. Real-time autofluorescence endoscopy is a useful adjunct to conventional white-light endoscopy for detecting early gastric cancer.

A new technique: Light-induced fluorescence endoscopy in combination with pharmacoendoscopy

Background: Most cancers and adenomas of the GI tract are easily detected by light-induced fluorescence endoscopy (LIFE-GI). However, some tumors are poorly visualized by using this technique. To investigate whether the spraying of noradrenaline on the lesion provides better visualization of the boundaries of neoplasms, the conventional and LIFE-GI endoscopic observations were made before and after spraying of nonadrenaline. Methods: Seven patients with gastric cancers were studied. After a conventional fiberscopic examination, a LIFE-GI procedure was performed, and then 20 mL of 0.02% noradrenaline solution was sprayed on the lesion. Results: The normal mucosa became paler than the tumor after spraying noradrenaline, thereby clarifying the tumor boundary in the LIFE-GI image. Conclusions: The combined use of pharmacoendoscopy with LIFE-GI is useful in the detection of gastric malignant tumors because it enhances the boundaries of these lesions.

A new technique: Light-induced fluorescence endoscopy in combination with pharmacoendoscopy

A new technique: Light-induced fluorescence endoscopy in combination with pharmacoendoscopy

Endoscopic and histologic diagnosis of Barrett esophagus.

Endoscopy plays an important role in the identification, diagnosis, and treatment of Barrett esophagus. Short-segment (<2-3 cm) and traditional long-segment (>2-3 cm) Barrett esophagus are distinguished solely on the length of metaplastic tissue above the esophagogastric junction. The histologic hallmark of intestinal metaplasia is required to confirm diagnosis. Biopsy specimens obtained from tissue of presumed Barrett esophagus or an irregular Z line confirm metaplastic glandular mucosa and permit evaluation of dysplastic or neoplastic changes. In the appropriate clinical setting, the use of adjunctive diagnostic techniques may facilitate the diagnosis of Barrett esophagus and sequelae such as dysplasia. Chromoendoscopy with high-resolution or magnified endoscopy is simple, safe, and desirable for surveillance but requires additional procedural time. The use of light-induced fluorescence endoscopy and light-scattering spectroscopy (i.e., optical biopsy) is appealing for the diagnosis and characterization of suspicious lesions. Adjunctive endoscopic techniques and adherence to a protocol for performing biopsies facilitate the early detection and subsequent surveillance of Barrett esophagus.

Endoscopic and Histologic Diagnosis of Barrett Esophagus

Endoscopy plays an important role in the identification, diagnosis, and treatment of Barrett esophagus. Short-segment ( 2-3 cm) Barrett esophagus are distinguished solely on the length of metaplastic tissue above the esophagogastric junction. The histologic hallmark of intestinal metaplasia is required to confirm diagnosis. Biopsy specimens obtained from tissue of presumed Barrett esophagus or an irregular Z line confirm metaplastic glandular mucosa and permit evaluation of dysplastic or neoplastic changes. In the appropriate clinical setting, the use of adjunctive diagnostic techniques may facilitate the diagnosis of Barrett esophagus and sequelae such as dysplasia. Chromoendoscopy with high-resolution or magnified endoscopy is simple, safe, and desirable for surveillance but requires additional procedural time. The use of light-induced fluorescence endoscopy and light-scattering spectroscopy (i.e., optical biopsy) is appealing for the diagnosis and characterization of suspicious lesions. Adjunctive endoscopic techniques and adherence to a protocol for performing biopsies facilitate the early detection and subsequent surveillance of Barrett esophagus.

Cytologic findings of the atypical cells possibly derived from preinvasive bronchial lesions detected by Light-Induced Fluorescence Endoscopy (LIFE) as a detailed examination in lung cancer screening system using sputum cytology

Cytologic findings of the atypical cells possibly derived from preinvasive bronchial lesions detected by Light-Induced Fluorescence Endoscopy (LIFE) as a detailed examination in lung cancer screening system using sputum cytology

3451 Enhanced better detection of gastric cancers by autofluorescence endoscopy coupled with the noradrenaline spraying method (pharmaco life-gi).

Background and Purpose: The light induced fluorescence endoscopy (LIFEGI: Zillix and Olympus) system has been reported to facilitate detection of cancers of gastrointestinal (GI) tract. However, the marginal image of tumors by LIFE-GI is sometimes unclear, due to fluorescence-influencing biological substance such as blood pigments, porphyrin and flavins. The pharmacoendoscopy, in which noradrenaline is sprayed onto tumors is reported to emphasize the tumor margin by the decreased blood flow in tumors and adjacent tissue. In order to enhance autofluorescent tumor image, we used pharmacoendoscopy simultaneously with LIFE-GI (pharmaco LIFE-GI). Patients and Methods: Subjects were 21 cases of gastric cancers, including 16 early and 5 advanced cancers. After a conventional endoscopic examination followed by the regular LIFE-GI observation, 20 ml of 0.02 % noradrenaline was sprayed onto the tumors and LIFE-GI images were obtained 5 minutes later. In order to evaluate the enhanced detectability of cancers, three examiners scored each case independently based on the enhancement of tumor margins; 0: no or minimal enhancement, +1: moderate enhancement, +2: marked enhancement. All cancers were observed as emitting dark red color under LIFE-GI against the background normal tissue emitting green color. Results: Regarding the scores of the tumors image enhancement, 4 of 21 cases were of +2 score, 12 cases of +1 score, and the rest of the cases (5 cases) of 0 score, indicating that 76.2 % of tumors was significantly enhanced by a pharmaco LIFE-GI. Conclusion:From the result of this study, marginal images of the tumors have been well enhanced by our new technique, a pharmaco LIFE-GI, which may be useful for better detection of gastric cancers.

3438 Detection of early gastric cancer by a real-time autofluorescence imaging system.

Aim: In recent years, a light-induced fluorescence endoscopy in the gastrointestinal tract system (LIFE-GI system) has been developed by Xillix Technology Co., Canada and Olympus Optical Co., Japan. This system has already been applied clinically. The purpose of this study was to demonstrate the feasibility of the LIFE-GI system for differentiating early gastric cancer from any other benign lesions. Methods: The LIFE-GI system is based on detecting tissue autofluorescence excited at 437 nm with a mercury lamp and a blue excitation filter. The subjects were 52 patients with 54 lesions (33 with early gastric cancer, 10 with gastric ulcer, 6 with hyperplastic polyp and 5 with erosion). Systemic endoscopic inspection was carried out first with ordinary white light endoscopy, followed by autofluorescence endoscopic observation. All procedures were documented with video and still images. After obtaining the LIFE image, biopsy samples were taken from the abnormal areas, as well as from adjacent normal mucosa. In addition, the LIFE image of gastric cancer was compared with the histology in the resected specimens. Results: The relationship between the autofluorescence image and the histology revealed that 21 of 33 carcinomas appeared dark red, 10 appeared mixed pattern with dark red and white fluorescence, and the remaining two could not be detected. Furthermore, the cancer extension recognized by this system corresponded well to that confirmed by the histology in 85% (28/33). On the other hand, 18 of 21 benign lesions appeared light blue similar to normal mucosa, while the others' showed reddish color. The sensitivity and specificity were 94% and 86%, respectively. Conclusion: The real-time autofluorescence endoscopy is a promising system for the detection or assessment of the extension of early gastric cancer as an adjunct to ordinary white light endoscopy. This work was supported in a Grant-in-Aid for Cancer Research from the Ministry of Health and Welfare of Japan.