Autofluorescence imaging-assisted medical thoracoscopy in the diagnosis of malignant pleural disease

BACKGROUND

Medical thoracoscopy (MT) does not always provide a conclusive diagnosis of pleural diseases because the endoscopic appearance of pleural diseases can be misleading. Autofluorescence imaging (AFI) is an effective assistive diagnostic tool. However, its clinical application for pleural disease remains controversial.

OBJECTIVES

This prospective study evaluated the clinical usefulness of AFI-assisted MT for diagnosis of malignant pleural diseases.

METHODS

Patients with unexplained pleural effusion admitted to our clinics between December 2018 and September 2021 were enrolled. We performed white-light thoracoscopy (WLT) first, and then AFI, during MT. Images of endoscopic real-time lesions were recorded under both modes. Pleural biopsy specimens were analyzed pathologically. Between-groups differences in diagnostic sensitivity, specificity, positive-predictive value (PPV), and negative-predictive value (NPV) were assessed using 95% confidence intervals (CI). Receiver operating characteristic curves and decision curve analyses were employed to analyze the diagnostic efficiency of these two modes.

RESULTS

Of 126 eligible patients, 73 cases were diagnosed with malignant pleural disease. A total of 1292 biopsy specimens from 492 pleural sites were examined for pathological changes. The diagnostic sensitivity, PPV, and NPV of AFI were 99.7%, 58.2%, and 99.2%, respectively. AFI was significantly superior to WLT, which had a sensitivity of 79.7%, PPV of 50.7%, and NPV of 62.8%. Subgroup analysis showed that the AFI type III pattern was significantly more specific for pleural malignant disease than that of WLT.

CONCLUSIONS

AFI could further improve the diagnostic efficacy of MT by providing better visualization, convenience, and safety.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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?

BACKGROUND

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).

METHODS

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.

RESULTS

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.

CONCLUSION

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.

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.

Advanced endoscopic imaging for early gastric cancer

Considerable numbers of early gastric cancers can be missed or misdiagnosed with conventional white light imaging endoscopy (WLI), thus advanced endoscopic imaging modalities have been applied to overcome the issue. High definition endoscopy can improve diagnostic accuracy, but still misses 20-25% of early gastric cancer. Magnifying endoscopy combined with narrow band imaging (NBI) allows for very high accuracy, with sensitivity and specificity of over 95%. The algorithm for magnifying endoscopy diagnosis of gastric cancer is composed of 1) presence of demarcation line, and 2) presence of irregular microsurface and/or microvascular pattern. Ultra-high magnification of 400 times with endocytoscopy (ECS) can produce images reflecting structural and cellular atypia. Using high grade ECS atypia as the diagnostic criteria for gastric cancer, ECS achieves a high diagnostic accuracy (86% of sensitivity, 100% of specificity) although approximately 10% of target lesions are not assessable because of poor dye staining.

Recent advances in targeted endoscopic imaging: Early detection of gastrointestinal neoplasms

Molecular imaging has emerged as a new discipline in gastrointestinal endoscopy. This technology encompasses modalities that can visualize disease-specific morphological or functional tissue changes based on the molecular signature of individual cells. Molecular imaging has several advantages including minimal damage to tissues, repetitive visualization, and utility for conducting quantitative analyses. Advancements in basic science coupled with endoscopy have made early detection of gastrointestinal cancer possible. Molecular imaging during gastrointestinal endoscopy requires the development of safe biomarkers and exogenous probes to detect molecular changes in cells with high specificity anda high signal-to-background ratio. Additionally, a high-resolution endoscope with an accurate wide-field viewing capability must be developed. Targeted endoscopic imaging is expected to improve early diagnosis and individual therapy of gastrointestinal cancer.

Esophageal squamous cell carcinoma - precursor lesions and early diagnosis

Squamous cell carcinoma of the esophagus (SCCE) carries a poor prognosis due to late diagnosis. Early detection is highly desirable, since surgical and endoscopic resection offers the only possible cure for esophageal cancer. Population screening should be undertaken in high risk areas, and in low or moderate risk areas for people with risk factors (alcoholics, smokers, mate drinkers, history of head and neck cancer, achalasia and lye stricture of the esophagus). Esophageal balloon cytology is an easy and inexpensive sampling technique, but the current methods are insufficient for primary screening due to sampling errors. Conventional endoscopy with biopsy remains the standard procedure for the identification of pre-malignant and early malignant changes in esophageal mucosa and endoscopic detection. It may be enhanced by several techniques such as dye and optic chromoendoscopy, magnifying endoscopy, and optical-based spectroscopic and imaging modalities. Since more than 80% of SCCE deaths occur in developing countries, where expensive techniques such as narrow band imaging (NBI) and autofluorescence imaging are unavailable, the most cost-effective tool for targeting biopsies may be Lugol dye chromoendoscopy, since it is easy, accurate, inexpensive and available worldwide. In ideal conditions, or in developed countries, is it reasonable to think that optimal detection will require a combination of techniques, such as the combination of Lugol’s chromoendoscopy and NBI to identify esophageal areas that require further characterization by a high resolution technique. The efficacy and cost-effectiveness will determine whether these modalities will become part of standard endoscopy practice.