Surface maturation scoring for oesophageal squamous intraepithelial neoplasia: a novel diagnostic approach inspired by first endomicroscopic 3-dimensional reconstruction

Confocal Laser Endomicroscopy for Detection of Early Upper Gastrointestinal Cancer

Esophageal and gastric cancers are common diseases with high morbidity and mortality; thus, early detection and treatment are beneficial to improve prognosis. Confocal laser endomicroscopy (CLE) is a novel imaging technique that permits the histological analysis of tissues during endoscopy. CLE has been shown to uniquely affect the diagnosis of early upper gastrointestinal cancers. Relevant literature was searched using PubMed and Google Scholar databases. Despite inherent flaws, CLE can reduce tissue damage and improve diagnostic accuracy to a certain extent. CLE in combination with other imaging methods can help enhance the detection rate and avoid unnecessary biopsies in the management of esophageal or gastric cancer and precancerous lesions. CLE is of great significance in the diagnosis and surveillance of early cancers of the upper gastrointestinal tract. Further technical innovations and the standardisation of CLE will make it more responsive to the needs of routine clinical applications.

Diagnostic accuracy of probe-based confocal laser endomicroscopy in Lugol-unstained esophageal superficial lesions of patients with head and neck cancer

BACKGROUND AND AIMS

Surveillance programs of patients with head and neck cancer (HNC) detect synchronous or metachronous esophageal squamous cell carcinoma (ESCC) in up to 15% of patients. Noninvasive, probe-based confocal laser endomicroscopy (pCLE) technique may improve the diagnosis allowing acquisition of high-resolution in vivo images at the cellular and microvascular levels. The aim of this study was to evaluate the accuracy of pCLE for the differential diagnosis of nonneoplastic and neoplastic Lugol-unstained esophageal lesions in patients with HNC.

METHODS

Twenty-seven patients with HNC who exhibited Lugol-unstained esophageal lesions at surveillance endoscopy were prospectively included for pCLE. Diagnostic pCLE was followed by subsequent biopsies or endoscopic resection of suspected lesions. A senior pathologist was blinded to the pCLE results.

RESULTS

Patients mean age was 59 years (SD = 8.8) and 70.4% were men. All patients were smokers, and 22 patients (81.5%) had a history of alcohol consumption. The locations of HNC were oral cavity (n = 13), larynx (n = 10), and pharynx (n = 4). Thirty-seven lesions in 27 patients were studied. The final diagnoses were ESCC in 17 patients and benign lesions in 20 patients. Sensitivity, specificity, and accuracy of pCLE for the histologic diagnosis of ESCC in patients with HNC were 94.1%, 90.0%, and 91.9%, respectively.

CONCLUSIONS

First, pCLE is highly accurate for real-time histology of Lugol-unstained esophageal lesions in patients with HNC. Second, pCLE may alter the management of patients under surveillance for ESCC, guiding biopsies and endoscopic resection, avoiding further diagnostic workup or therapy of benign lesions.

Diagnostic value of probe-based confocal laser endomicroscopy and high-definition virtual chromoendoscopy in early esophageal squamous neoplasia

BACKGROUND

Detection and differentiation of esophageal squamous neoplasia (ESN) are of value in improving patient outcomes. Probe-based confocal laser endomicroscopy (pCLE) can serve in targeted biopsies in the diagnosis of GI neoplasia. However, its performance in ESN has not yet been reported.

OBJECTIVE

To investigate the diagnostic value of pCLE for early ESN screened by high-definition virtual chromoendoscopy (I-Scan) and verified by Lugol chromoendoscopy and histopathology.

DESIGN

Prospective and noninferiority trial.

SETTING

Single center in China.

PATIENTS

Patients were enrolled who (1) previously had histologically verified early ESN or (2) were about to undergo screening endoscopy and were 50 to 80 years of age between February 2013 and February 2014.

INTERVENTIONS

The esophagus was investigated sequentially by white-light endoscopy, I-Scan, then pCLE and iodine chromoendoscopy. The results were interpreted and compared with histopathologic results.

MAIN OUTCOME MEASUREMENTS

Diagnostic characteristics of pCLE and I-Scan.

RESULTS

In total, 356 patients were enrolled. In all, 42 patients were histologically proven to have 47 neoplasias. The diagnostic value of pCLE for ESN during ongoing endoscopy has a sensitivity, specificity, and accuracy of 94.6%, 90.7%, and 92.3%, respectively. The interobserver and intraobserver agreement was good and excellent, with κ values of 0.699 and 0.895, respectively. The detection rate by using I-Scan and Lugol chromoendoscopy was 10.4% and 12.9%, respectively (P<.01 for noninferiority).

LIMITATIONS

Single center.

CONCLUSIONS

pCLE shows promise in diagnosing and differentiating ESN in vivo. The screening performance of I-Scan in the detection of ESN is noninferior to that of iodine chromoendoscopy.

Early esophageal cancer screening in China

In China, the incidence of esophageal cancer (EC) and its related mortality are high. Screening strategies aiming at early diagnosis can improve the prognosis. Researches on detection of early EC, especially in China are reviewed. Compared to esophageal balloon cytology or routine endoscopy, chromoendoscopy with Lugol's staining and biopsy appears to be the gold standard for early EC diagnosis in China today. Narrow-band imaging endoscopy, Confocal Laser endomicroscopy and other novel diagnostic approaches are more and more widely used in developed urban areas, but cost and lack of essential training to the endoscopists have made their use limited in rural areas. No specific biomarkers or serum markers were strongly commended to be used in screening strategies currently, which need to be evaluated in future. Trials on organized screening have been proposed in some regions of china with high disease prevalence. Screening in these areas has been shown to be cost effective.

Comparison between two types of confocal laser endomicroscopy in gastrointestinal tract

OBJECTIVES

Confocal laser endomicroscopy (CLE) consists of endoscope-based CLE (eCLE) and probe-based CLE (pCLE). This study aimed to compare eCLE and pCLE in their diagnostic yield in different parts of the gastrointestinal (GI) tract.

METHODS

Consecutive patients were scheduled for CLE examination due to GI symptoms. All patients were randomly assigned to eCLE or pCLE group and underwent a programmed procedure using one type of CLE. Differences in procedure time, complication rate, CLE image quality and image acquisition feasibility between these two types of CLE for esophagogastroduodenoscopy (EGD) and colonoscopy were calculated.

RESULTS

Altogether 513 CLE procedures were performed, including 324 EGD and 189 colonoscopy. The procedure time of pCLE was significantly shorter than that of eCLE both in EGD and colonoscopy (16.78 min vs 18.13 min for EGD, P = 0.027; 32.48 min vs 39.89 min for colonoscopy, P < 0.001). No significant difference was found between these two types of CLE in diagnostic utility, including the detection and prediction of histopathological results of the lesions. The CLE image quality of both eCLE and pCLE were comparable in the stomach and colon, but eCLE seemed to be superior to pCLE in examining the esophagus. Colonoscopy using pCLE had a higher complete rate than that of eCLE, although the difference was not statistically significant (P = 0.065).

CONCLUSIONS

pCLE is more flexible in diagnosing GI diseases with a shorter procedure time than eCLE regardless of comparable diagnostic yields, except the diagnosis of esophageal diseases in which eCLE provides better image quality.

Learning curve and interobserver agreement of confocal laser endomicroscopy for detecting precancerous or early-stage esophageal squamous cancer

Background

Confocal laser endomicroscopy (CLE) can provide in vivo subcellular resolution images of esophageal lesions. However, the learning curve in interpreting CLE images of precancerous or early-stage esophageal squamous cancer is unknown. The goal of this study is to evaluate the diagnostic accuracy and inter-observer agreement for differentiating esophageal lesions in CLE images among experienced and inexperienced observers and to assess the learning curve.

Method

After a short training, 8 experienced and 14 inexperienced endoscopists evaluated in sequence 4 sets of high-quality CLE images. Their diagnoses were corrected and discussed after each set. For each image, the diagnostic results, confidence in diagnosis, quality and time to evaluate were recorded.

Results

Overall, diagnostic accuracy was greater for the second, third, fourth set of images as compared with the initial set (odds ratio [OR] 2.01, 95% CI 1.22–3.31; 7.95, 3.74–16.87; and 6.45, 3.14–13.27), respectively, with no difference between the third and fourth sets in accuracy (p = 0.67). Previous experience affected the diagnostic accuracy only in the first set of images (OR 3.70, 1.87–7.29, p<0.001). Inter-observer agreement was higher for experienced than inexperienced endoscopists (0.732 vs. 0.666, p<0.01)

Conclusion

CLE is a promising technology that can be quickly learned after a short training period; previous experience is associated with diagnostic accuracy only at the initial stage of learning.

Evaluation of new morphometric parameters of neoangiogenesis in human colorectal cancer using confocal laser endomicroscopy (CLE) and targeted panendothelial markers

The tumor microcirculation is characterized by an abnormal vascular network with dilated, tortuous and saccular vessels. Therefore, imaging the tumor vasculature and determining its morphometric characteristics represent a critical goal for optimizing the cancer treatment that targets the blood vessels (i.e. antiangiogenesis therapy). The aim of this study was to evaluate new vascular morphometric parameters in colorectal cancer, difficult to achieve through conventional immunohistochemistry, by using the confocal laser endomicroscopy method. Fresh biopsies from tumor and normal tissue were collected during colonoscopy from five patients with T3 colorectal carcinoma without metastasis and were marked with fluorescently labeled anti-CD31 antibodies. A series of optical slices spanning 250 µm inside the tissue were immediately collected for each sample using a confocal laser endomicroscope. All measurements were expressed as the mean ± standard error. The mean diameter of tumor vessels was significantly larger than the normal vessels (9.46±0.4 µm vs. 7.60±0.3 µm, p = 0.0166). The vessel density was also significantly higher in the cancer vs. normal tissue samples (5541.05±262.81 vs. 3755.79±194.96 vessels/mm3, p = 0.0006). These results were confirmed by immunohistochemistry. In addition, the tortuosity index and vessel lengths were not significantly different (1.05±0.016 and 28.30±3.27 µm in normal tissue, vs. 1.07±0.008 and 26.49±3.18 µm in tumor tissue respectively, p = 0.5357 and p = 0.7033). The daughter/mother ratio (ratio of the sum of the squares of daughter vessel radii over the square of the mother vessel radius) was 1.15±0.09 in normal tissue, and 1.21±0.08 in tumor tissue (p = 0.6531). The confocal laser endomicroscopy is feasible for measuring more vascular parameters from fresh tumor biopsies than conventional immunohistochemistry alone. Provided new contrast agents will be clinically available, future in vivo use of CLE could lead to identification of novel biomarkers based on the morphometric characteristics of tumor vasculature.