Autofluorescence Endoscopy Research Articles

Clinical manifestations of autoimmune rheumatic diseases in the larynx

Introduction. Autoimmune rheumatic diseases are attributed to a systemic process that develops in many organs, including the larynx. Complaints of impaired vocal function in patients with this pathology require a thorough clinical and endoscopic analysis.The purpose of the study. To determine the clinical-endoscopic changes of the larynx in patients with impaired vocal function in autoimmune rheumatic diseases..Materials and methods. 31 (100%) patients aged 25 to 84 (41 ± 15) years with autoimmune rheumatic diseases applied to the phoniatric department of the St. Petersburg Research Institute of ENT. There were 3 men (10%), 28 women (90%). All patients complained of impaired vocal function, 5 of the examined (16%) were also concerned about breathing disorders during exercise or at rest.Patients were grouped into three groups: systemic lupus erythematosus 4 (13%) people, systemic vasculitis 10 (32%) people, rheumatoid arthritis 17 (55%) people.Videolaryngoscopy, videolaryngostroboscopy, autofluorescence endoscopy, NBI – endoscopy (according to indications) were used to make the diagnosis.Results. The distribution of laryngeal pathology by nosological forms in patients with аutoimmune rheumatic diseases was as follows. The most numerous were groups with functional dysphonia of the hypotonic type 10 (32%) and bamboo nodules of 8 (26%) patients. Chronic laryngeal stenosis was diagnosed in 5 (16%), and chronic catarrhal laryngitis and soft nodules of the vocal folds in 3 (9.5%) people in each group (respectively). The smallest number of patients suffered from ulcerative necrotic changes of the larynx and pharynx – 2 (7%).Conclusion. Thus, laryngeal changes in аutoimmune rheumatic diseases had both specific manifestations and non-specific ones. The latter include functional dysphonia of the hypotonic type, chronic catarrhal laryngitis, soft nodules of the vocal folds. Bamboo nodules of the vocal folds, ulcerative necrotic diseases, chronic laryngeal stenosis (infiltrative and scarring) were specific for patients with аutoimmune rheumatic diseases.

Endoscopic autofluorescence imaging in the diagnosis of premalignant lesions and laryngeal/hypopharyngeal cancer

The purpose of the study was to assess the diagnostic value of endoscopic autofluorescence imaging (AFI) in patients with premalignant lesions and primary laryngeal/hypopharyngeal cancer.Material and Methods. The diagnostic value of AFI was assessed in 53 patients with chronic hyperplastic laryngeal/hypopharyngeal lesions and 48 patients with laryngeal/hypopharyngeal cancer.Results. The inclusion of video laryngoscopy with AFI in the algorithm for examining patients with chronic diseases of the upper respiratory tract made it possible to significantly improve the diagnostic efficacy of endoscopic examination in patients with premalignant lesions (high grade dysplasia) of the laryngeal mucosa. Video laryngoscopy with AFI was found to achieve higher sensitivity, specificity and accuracy rates than white light video laryngoscopy (87.5, 96.9 and 92.5 vs 50.0, 96.0 and 71.7 %, respectively, p<0.05). The video laryngoscopy with AFI allowed identification of not only pathological changes in the laryngeal and hypopharyngeal mucosa but also their malignant potential, as well as identification of areas for targeted biopsy. In 9 (18.8 %) laryngeal cancer patients, the standard white light video laryngoscopy demonstrated difficulties in the differential diagnosis of laryngeal cancer (n=4) and in assessing the extent of laryngeal cancer (n=5). In 3 out of 4 diagnostically difficult cases, video laryngoscopy with AFI made it possible to confirm the diagnosis of laryngeal cancer and in 5 cases to accurately determine the extent of hypopharyngeal cancer.Conclusion. The addition of standard videolaryngoscopy with a hightech technique of autofluorescence endoscopy makes it possible to accurately diagnose premalignant and malignant lesions of the larynx and hypopharynx.

Prospects for the use of autofluorescence endoscopy in rhinosurgery

To assess the possibility of using autofluorescence endoscopy to control the condition of flaps of the nasal mucous membrane after surgical interventions. The assessment of the processes of biological destruction of 15 fragments of the mucous membrane of the inferior nasal concha, obtained during intranasal interventions with endoscopic technique in autofluorescence mode, followed by histological examination at different periods of observation, has been conducted. The results of the proposed method were tested in 84 patients with chronic and intraoperative defects of the nasal septum after the surgical intervention. It has been shown that autofluorescence endoscopy can be used to assess the viability of flaps of the nasal cavity's mucous membrane. A change of the autofluorescence signal to a whitish and orange shades indicates the presence of ischemia and necrosis. Method sensitivity was 92.3%, specificity was 95.8% and total accuracy was 95.4%. This method is promising for predicting the long-term outcomes of surgical treatment of the nasal septum's perforation in relation to the risk of reperforation forming, as well as for assessment of the functional viability of local flaps in plastic reconstruction of defects of the anterior skull base.

Autofluorescence Image-Guided Endoscopy in the Management of Upper Aerodigestive Tract Tumors.

At this juncture, autofluorescence and narrow-band imaging have resurfaced in the medicine arena in parallel with current technology advancement. The emergence of newly developed optical instrumentation in addition to the discovery of new fluorescence biomolecules have contributed to a refined management of diseases and tumors, especially in the management of upper aerodigestive tract tumors. The advancement in multispectral imaging and micro-endoscopy has also escalated the trends further in the setting of the management of this tumor, in order to gain not only the best treatment outcomes but also facilitate early tumor diagnosis. This includes the usage of autofluorescence endoscopy for screening, diagnosis and treatment of this tumor. This is crucial, as microtumoral deposit at the periphery of the gross tumor can be only assessed via an enhanced endoscopy and even more precisely with autofluorescence endoscopic techniques. Overall, with this new technique, optimum management can be achieved for these patients. Hence, the treatment outcomes can be improved and patients are able to attain better prognosis and survival.

Video endoscopic methods of laryngeal examination in modern phoniatry

Introduction. Modern diagnostics of laryngeal diseases is based on the use of video endoscopic technologies. The authors of the article, having almost thirty years of experience with various methods of video endoscopy, proposed a classification of video endoscopic methods of laryngeal examination. Objective. To develop an algorithm for the application of various video endoscopic methods of laryngeal examination in voice professionals with functional and organic dysphonia. Materials and methods. From 2020 to 2022, 2308 patients aged 18 to 80 years (43.2 ± 11.5) were examined in the phoniatric department of the St. Petersburg Research Institute of ENT. There were 1424 women (61,7 %), 884 men (38,3 %) people. Functional dysphonia was detected in 705 (30,5 %) people, acute and chronic laryngitis in 668 (28,9 %), tumor-like formations in 436 (18,9 %), the remaining nosological forms were diagnosed in 499 (21,7). All the patients turned out to be representatives of voice-speaking professions and complained of dysphonia.For videolaryngoscopy, videolaryngostroboscopy, autofluorescence endoscopy, NBI–endoscopy, equipment from various manufacturers was used. Results. An algorithm for the application of video endoscopic research methods in persons of voice-speech professions with dysphonia has been developed. Overview videolaryngoscopy and videostroboscopy were mandatory research methods for all patients with complaints of voice function. The use of these two methods proved to be sufficient for the diagnosis of functional dysphonia, paresis and paralysis, congenital malformations of the larynx, scar stenosis. In-depth diagnostics and differential diagnostics of tumor-like formations, various forms of chronic laryngitis, benign and malignant formations, in addition to videolaryngoscopy and videostroboscopy, included autofluorescence endoscopy or NBI endoscopy, which revealed the earliest stages of the pathological process. Conclusions. Only the complex application of various methods of video endoscopy of the larynx provided timely diagnosis and early treatment of dysphonia, maximum restoration of voice function, and, consequently, the preservation of professional longevity by persons of voice-speech professions.

Tracheal amyloidosis visualized by autofluorescence endoscopy

Tracheal amyloidosis visualized by autofluorescence endoscopy

Localized intestinal AL amyloidosis detected as bright green using autofluorescence endoscopy.

Amyloidosis is classifiable as systemic, with amyloid deposition in organs throughout the body, or localized, involving only one organ. Amyloidosis localized in the intestinal tract is rare. This report describes three cases of localized AL amyloidosis in the intestinal tract and presents their clinical characteristics, endoscopic findings, and prognoses. All three cases were asymptomatic, and were found accidentally during endoscopy for closer examination after a positive fecal occult blood test. Endoscopic findings included patchy redness and meandering dilated vessels of the lesion. Using autofluorescence (AFI) endoscopy, the lesion of amyloid deposition was enhanced as bright green. We used fluorescence microscopy to observe unstained specimens obtained from an amyloid deposition site with excitation light. Autofluorescence was detected with the broad excitation wavelength at amyloid deposition lesion sites of the specimen. Results revealed that AL amyloid has autofluorescence that engenders its detection by AFI endoscopy as bright green. In none of the three cases was systemic amyloidosis or organ failure observed. The long-term course of all the cases was favorable.

Úloha narrow band imaging a autofl uorescence při diagnostice karcinomu orofaryngu

Despite progress in the treatment of head and neck cancer, the five-year overall survival rate is still low because of late dia­gnosis. The head and neck mucosal tumours were usually dia­gnosed in higher stages in past, therefore new endoscopic optical imaging methods were developed for better and earlier detection of these lesions. They are divided in two main groups – horizontal and vertical methods. The horizontal ones show the surface of the mucous membrane (narrow band imaging, autofluorescence, photodynamic dia­gnosis, magnifying and contact endoscopy). The vertical ones show different layers of the mucosa (optical coherence tomography and confocal endomicroscopy). Narrow band imaging and autofluorescence endoscopy are already used routinely in foreign countries, magnifying and contact endoscopy are getting to practice recently. The authors present a summary of narrow band imaging and autofluorescence endoscopy usage in the dia­gnostics of oropharyngeal carcinoma.

Research Progress of Autofluorescence Imaging Technology in the Diagnosis of Early Gastrointestinal Tumors.

Early diagnosis and early treatment of gastrointestinal tumors are helpful to improve the prognosis of patients. Endoscopy is the best method for the diagnosis of early gastrointestinal tumors, but some early flat tumors may be missed under conventional white-light endoscopy. In order to improve the accuracy of endoscopic diagnosis of gastrointestinal tumors, especially early flat tumors, endoscopic autofluorescence imaging (AFI) as a new technique has been widely used in clinics in recent years. This article reviews the progress of the clinical application of AFI in the diagnosis of various gastrointestinal tumors.

Endoscopic visualization of cancer and dysplasia in patients with ulcerative colitis following sensitization with oral 5-aminolevulinic acid.

ObjectiveEarly diagnosis of colitis‐associated cancer and dysplasia through surveillance endoscopy is vital for patients with ulcerative colitis (UC). This study aimed to evaluate the efficacy of autofluorescence endoscopy (AFE) using 5‐aminolevulinic acid (ALA) and to investigate the fluorescence signal localization pattern following 5‐ALA administration in tumorous lesions diagnosed as colitis‐associated cancer and dysplasia. The sensitivity and specificity of tumorous lesions detected by white light endoscopy (WLE) with and without AFE were evaluated.MethodsOverall, 13 endoscopic procedures were performed in 11 patients with UC using WLE and AFE following the oral administration of 5‐ALA. The biopsied lesions detected via endoscopy and resected specimens from cases underwent colectomy were assessed histopathologically. The sensitivity and specificity of detecting tumorous lesions by WLE with and without AFE were evaluated.ResultsOf the 68 lesions detected and biopsied, 63 were detected via WLE, and five were detected via AFE alone. The sensitivity of detecting colitis‐associated cancer and dysplasia via WLE combined with AFE was 36.4%, and the specificity, positive predictive value and negative predictive value were 94.2%, 57.1%, and 87.5%, respectively. Tumorous lesions displayed three types of fluorescence patterns on AFE.ConclusionsAFE using 5‐ALA can detect colitis‐associated cancer and dysplasia in patients with long‐standing UC and lesions that could not be detected via WLE. The distinctive fluorescence patterns in lesions may permit qualitative diagnoses of colitis‐associated cancer and dysplasia.

Development of a Robust Autofluorescence Lifetime Sensing Method for Use in an Endoscopic Application.

Endoscopic autofluorescence lifetime imaging is a promising technique for making quantitative and non-invasive diagnoses of abnormal tissue. However, motion artifacts caused by vibration in the direction perpendicular to the tissue surface in a body makes clinical diagnosis difficult. Thus, this paper proposes a robust autofluorescence lifetime sensing technique with a lens tracking system based on a laser beam spot analysis. Our optical setup can be easily mounted on the head of an endoscope. The variation in distance between the optical system and the target surface is tracked by the change in the spot size of the laser beam captured by the camera, and the lens actuator is feedback-controlled to suppress motion artifacts. The experimental results show that, when using a lens tracking system, the standard deviation of fluorescence lifetime is dramatically reduced. Furthermore, the validity of the proposed method is experimentally confirmed by using a bio-mimicking phantom that replicates the shape, optical parameters, and chemical component distribution of the cancerous tissue.

Systematic review with network meta-analysis: endoscopic techniques for dysplasia surveillance in inflammatory bowel disease.

International guidelines recommend dysplasia surveillance in IBD. To compare endoscopic techniques for dysplasia surveillance METHODS: We searched MEDLINE, Embase, CENTRAL for randomised trials through May 2019. We estimated odds ratios (ORs) for binary and mean differences (MDs) for continuous outcomes, using frequentist random-effects network meta-analysis. We assessed study risk of bias and appraised evidence certainty using GRADE. Eighteen trials (2638 participants) were included. Standard definition white-light endoscopy (OR 0.44, 95% CI 0.26-0.73; high certainty) and i-SCAN (OR 0.47, 95% CI 0.25-0.90; moderate certainty) had lower odds of detecting neoplasia than chromoendoscopy. Fujinon intelligent colour enhancement (FICE), standard definition white-light endoscopy and i-SCAN had lower odds for this outcome than full spectrum high definition white-light endoscopy (ORs 0.02 to 0.15; low certainty). Standard definition white-light endoscopy had lower odds of detecting nonpolypoid neoplasia than full spectrum high definition white-light endoscopy, narrow band imaging, chromoendoscopy and high definition white-light endoscopy (ORs 0.01-0.14; moderate certainty). Full spectrum high definition white-light endoscopy ranked as the best technique for both outcomes (moderate certainty). Standard definition white-light endoscopy had lower odds of detecting neoplasia by target biopsy (OR 0.27, 95% CI 0.08-0.91) and had shorter procedure time (MD -14.81minutes, 95% CI -25.03, -4.06) than chromoendoscopy (moderate certainty). Chromoendoscopy, high definition white-light endoscopy, narrow band imaging, autofluorescence, FICE and full spectrum high definition white-light endoscopy may be comparable for dysplasia surveillance. Standard definition white-light endoscopy and i-SCAN probably provide lower yields for neoplasia identification. Full spectrum high definition white-light endoscopy may represent the first-line approach.

Stratification of the dysplasia and neoplasia risk using autofluorescence endoscopic surveillance of Barrett's esophagus.

This study assessed the efficacy of autofluorescence endoscopy (AFE) using the Onco-LIFE system and numerical color value (NCV) estimation in comparison to white light endoscopy (WLE) in endoscopic surveillance for identification of early dysplasia in Barrett's esophagus (BE) to aid in real-time image elucidation and minimize the overreliance on biopsy and histology. AFE, performed simultaneously during WLE, with biopsy was performed among 24 patients with BE. None of these patients had any obvious mucosal abnormalities in WLE. A total of 376 biopsies were taken, include 325 randomly collected according to Seattle Protocol and 51 additional biopsies, taken from the sites with pathological AF and NCV. All biopsy sites were assessed in vivo using WLE, AFE and NCV and compared to histological examinations, to estimate the efficacy of these methods in dysplasia assessment in BE. In the case of 248 biopsies taken from sites with NCV below 1.0, two cases of unspecified dysplasia were recognized; in 14 biopsies with NCV above 2.0 in all cases the various grades of dysplasia were documented. Dysplasia was found in 42% of AFE + NCV- guided biopsy specimens, and in 7.1% of WLE-guided biopsy specimens. AFE + NCV detected high-grade dysplasia in 7 patients, 6 more than according to Seattle Protocol in WLE. The expected odds of dysplasia detection in a sample increases almost 1.9 times, if it was selected by the AFE method (p < 0.001), when compared to WLE and with accordance with Seattle Protocol guided biopsy. The above results indicate that AFE + NCV using the Onco-LIFE system leads to improved BE lesion visualization for targeted biopsy with accurate histologic correlation compared to WLE and Seattle Protocol guided biopsy alone, and can serve to minimize additional biopsies.

Does the Numerical Colour Value (NCV) correlate with preneoplastic and neoplastic colorectal lesions?

White light endoscopy (WLE) is the gold standard for detection of colorectal cancer. Autofluorescence endoscopy (AFE) is among the novel methods expected to increase the sensitivity and specificity of endoscopic diagnosis. The main objective of the study was to determine the diagnostic efficacy of AFE for the detection of preneoplastic and neoplastic colorectal lesions and to identify high-grade neoplasia using Numerical Colour Value (NCV). This retrospective study included 188 patients with colorectal mucosal lesions diagnosed on WLE and assessed using AFE; they were included in the study if a complete patient record was available (description of visualized colorectal lesions, NCV and histopathology report). The NCV was compared with the histological result. Histology revealed 38 hyperplastic colon polyps, 77 low-grade dysplastic lesions, 17 high-grade dysplastic lesions, 24 adenocarcinomas and 32 inflammatory lesions. The mean NCVs of high-grade dysplasia (HGD) and adenocarcinoma were 2.24 ± 0.22 and 2.73 ± 0.16, respectively, significantly higher than the NCV of hyperplastic colon polyps (0.95 ± 0.06), low-grade dysplasia (LGD) (1.27 ± 0.05) and inflammatory lesions (1.26 ± 0.17). The NCV cut-off value for HGD and adenocarcinoma was set at 1.7. The sensitivity, specificity, PPV (positive predictive value) and NPV (negative predictive value) were 95.2%, 87.9%, 97.5%, 84.8%, respectively. Our study showed that AFE could provide useful diagnostic information regarding preneoplastic and neoplastic colorectal lesions. Additionally, the NCV significantly correlated with the histopathology results.

The benefits of targeted endoscopic biopsy performed using the autofluorescence based diagnostic technique in 67 cases of diagnostically difficult gastrointestinal tumors.

The search for new diagnostic and therapeutic procedures is an essential task in contemporary oncology. The purpose of our study was the evaluation of the practical usefulness of autofluorescence endoscopy (AFE) using the Onco-LIFE system, compared with the use of white light endoscopy (WLE), and the estimation of the correlation between the histopathological evaluation with the degree of lesions' Numerical Color Value (NCV index) and the method's sensitivity and specificity valuation. 67 patients were analyzed at the Center for Laser Diagnostics and Therapy. All patients previously had a gastrointestinal tract tumor, which appeared malignant, but without histopathological confirmation. We measured NCV, estimated the correlation of the clinical diagnosis based on histopathological evaluation with the degree of NCV index from gastrointestinal lesions, and calculated the sensitivity and specificity of this method. In the group of 67 patients, we found 44 cases of primary or secondary cancers and 7 cases of non-epithelial malignancies. In this group (51 patients) we identified 13 colorectal cancers and 38 upper gastrointestinal cancers. Based on the NCV index at NCV > 1.0, we revealed, that the sensitivity for malignant neoplastic lesions was 100% and the specificity was 73%, while for NCV > 1.5, the sensitivity for malignant neoplastic lesions was 86% and the specificity 100%. AFE using the Onco-LIFE system is a helpful tool to perform targeted biopsies at the outset. A significant correlation was found between lesions' NCV index and the grade of dysplasia or tumor malignancy. AFE sensitivity and specificity is higher than WLE. Further studies are needed, especially performed by expert endoscopists.

Light and sound - emerging imaging techniques for inflammatory bowel disease.

Patients with inflammatory bowel disease are known to have a high demand of recurrent evaluation for therapy and disease activity. Further, the risk of developing cancer during the disease progression is increasing from year to year. New, mostly non-radiant, quick to perform and quantitative methods are challenging, conventional endoscopy with biopsy as gold standard. Especially, new physical imaging approaches utilizing light and sound waves have facilitated the development of advanced functional and molecular modalities. Besides these advantages they hold the promise to predict personalized therapeutic responses and to spare frequent invasive procedures. Within this article we highlight their potential for initial diagnosis, assessment of disease activity and surveillance of cancer development in established techniques and recent advances such as wide-view full-spectrum endoscopy, chromoendoscopy, autofluorescence endoscopy, endocytoscopy, confocal laser endoscopy, multiphoton endoscopy, molecular imaging endoscopy, B-mode and Doppler ultrasound, contrast-enhanced ultrasound, ultrasound molecular imaging, and elastography.

The combination of autofluorescence endoscopy and molecular biomarkers is a novel diagnostic tool for dysplasia in Barrett's oesophagus

ObjectiveEndoscopic surveillance for Barrett's oesophagus (BO) is limited by sampling error and the subjectivity of diagnosing dysplasia. We aimed to compare a biomarker panel on minimal biopsies directed by autofluorescence...

Third-generation autofluorescence endoscopy for the detection of early neoplasia in Barrett's esophagus: a pilot study

In Barrett's esophagus (BE), second-generation autofluorescence imaging (AFI-II) improves targeted detection of high-grade intra-epithelial neoplasia (HGIN) and early cancer (EC), yet suffers from high false-positive (FP) rates. The newest generation AFI (AFI-III) specifically targets fluorescence in malignant cells and may therefore improve detection of early neoplasia and reduce FP rate. The aim was to compare AFI-III with AFI-II for endoscopic detection of early neoplasia in BE. BE patients with endoscopically inconspicuous neoplasia underwent two diagnostic endoscopies (AFI-II/AFI-III) in a single session. End-points: number of patients and lesions with HGIN/EC detected with AFI-II and AFI-III after white-light endoscopy (WLE) and the value of reinspection of AFI-positive areas with WLE and narrow-band imaging. Forty-five patients were included (38 males, age 65 years). Nineteen patients showed HGIN/EC. AFI-II inspection after WLE increased detection of HGIN/EC from 9 to 15 patients (47 to 79%); AFI-III increased detection from 9 to 17 patients (47 to 89%). WLE plus random biopsies diagnosed 13/19 (68%) HGIN/EC patients. One hundred and four abnormal AFI areas were inspected; 23 (22%) showed HGIN/EC. AFI-II increased detection of HGIN/EC from 10 to 18 lesions (43 to 78%). AFI-III increased detection from 10 to 20 lesions (43-87%). FP rate was 86% for AFI-II and AFI-III. Reinspection with WLE or narrow-band imaging reduced FP rate to 21% and 22%, respectively, but misclassified HGIN/EC lesions as unsuspicious in 54% and 31%, respectively. This first feasibility study on third-generation AFI again showed improved targeted detection of HGIN/EC in BE. However, the results do not suggest AFI-III performs significantly better than conventional AFI-II.

A comparison of white light laryngostroboscopy versus autofluorescence endoscopy in the evaluation of vocal fold pathology

To prove the diagnostic value of autofluorescence endoscopy (AFE) and white light laryngostroboscopy (WLS) versus the gold standard microlaryngoscopy with histopathological examination in differential diagnostics of laryngeal lesions for experienced phoniatricians and laryngologists, using the PENTAX SAFE-3000 system. Exploratory cohort study. High-resolution rigid WLS was executed in 32 consecutive patients with initial manifestation of benign, precancerous, and malignant vocal fold lesions. Fiberoptic blue light AFE (SAFE-3000; λ = 408 nm) was subsequently performed by an experienced endoscopist in a blinded study setting. Findings were rated based on objective WLS and AFE parameters (e.g., phonatory vibration, mucosal wave propagation, and loss of autofluorescence). The clinically assumed WLS and AFE diagnoses were compared with the final histopathology of biopsied material taken during microlaryngoscopy. In reference to histopathological diagnosis, WLS achieved a higher sensitivity (100% vs. 94%), specificity (94% vs. 69%), and accuracy (97% vs. 81%) than AFE diagnostics. The concordance between both endoscopic techniques was 87.5% (28/32 patients); additional AFE benefits were not detectable. Significant loss of autofluorescence was observed in malignant findings clinically clearly diagnosed by WLS, but also in chronic inflammation, severe dysplasia, granulomas, vascular polyps, and glottal papillomatosis. The evaluation of vocal fold pathology by the clinically experienced examiner precisely applying WLS appears to be more reliable than diagnostics of mucosal tissue changes by means of AFE via the SAFE-3000 system as a relatively nonspecific method. Microlaryngoscopy with histopathological examination and phonomicrosurgical excision of pathologic changes remains the gold standard.

Computer-aided diagnosis of neoplastic colorectal lesions using ‘real-time’ numerical color analysis during autofluorescence endoscopy

Differentiating non-neoplastic colorectal lesions from neoplastic lesions during screening colonoscopies is essential to reduce the unnecessary treatment of non-neoplastic lesions. The present study was conducted to verify the diagnostic yields of the computer-aided diagnostic system that enables 'real-time' color analysis of colorectal lesions when applied to autofluorescence endoscopy (AFE). Consecutive patients who were scheduled to undergo a therapeutic colonoscopy in our department were enrolled in this study. The encountered lesions were evaluated in AFE and color-tone sampling was performed. Lesions with green/red (G/R) ratios less than 1.01 were judged to be neoplastic and those with G/R ratios of at least 1.01 were considered to be non-neoplastic. All lesions greater than 5 mm were endoscopically removed and lesions less than 5 mm were biopsied. During the study period, a total of 32 patients with 102 colorectal lesions were evaluated with AFE. The mean G/R ratio for all neoplastic lesions was 0.86 [95% confidence interval (CI), 0.63-1.01], which was significantly lower than the mean G/R ratio for non-neoplastic lesions (1.12; 95% CI, 0.98-1.26; P<0.001). The mean G/R ratios were 1.36 (95% CI, 1.21-1.57) in normal mucosa, 1.12 (95% CI, 0.98-1.26) in hyperplastic lesions, 0.88 (95% CI, 0.69-1.02) in adenomas, and 0.61 (95% CI, 0.54-0.73) in intramucosal cancers. A G/R ratio cutoff value of 1.01 was applied for discriminating between neoplastic lesions and non-neoplastic lesions, and yielded sensitivity, specificity, positive and negative predictive values of 94.2, 88.9, 95.6, and 85.2%, respectively. This diagnostic tool may lead to the reduction of unnecessary treatments for non-neoplastic lesions.