Optical EMR: confocal endomicroscopy-targeted EMR of focal high-grade dysplasia in Barrett's esophagus

Past, present and future of Barrett's oesophagus

Barrett's oesophagus is a condition which predisposes towards development of oesophageal adenocarcinoma, a highly lethal tumour which has been increasing in incidence in the Western world over the past three decades. There have been tremendous advances in the field of Barrett's oesophagus, not only in diagnostic modalities, but also in therapeutic strategies available to treat this premalignant disease. In this review, we discuss the past, present and future of Barrett's oesophagus. We describe the historical and new evolving diagnostic criteria of Barrett's oesophagus, while also comparing and contrasting the British Society of Gastroenterology guidelines, American College of Gastroenterology guidelines and International Benign Barrett's and CAncer Taskforce (BOBCAT) for Barrett's oesophagus. Advances in endoscopic modalities such as confocal and volumetric laser endomicroscopy, and a non-endoscopic sampling device, the Cytosponge, are described which could aid in identification of Barrett's oesophagus. With regards to therapy we review the evidence for the utility of endoscopic mucosal resection and radiofrequency ablation when coupled with better characterization of dysplasia. These endoscopic advances have transformed the management of Barrett's oesophagus from a primarily surgical disease into an endoscopically managed condition.

Advances in the Endoscopic Diagnosis of Barrett Esophagus

BACKGROUND

Barrett esophagus (BE) continues to be a major risk factor for developing esophageal adenocarcinoma.

METHODS

We review the risk factors, diagnosis, and management of BE, with an emphasis on the most current endoscopic diagnostic modalities for BE.

RESULTS

Novel diagnostic modalities have emerged to address the inadequacies of standard, untargeted biopsies, such as dye-based and virtual chromoendoscopy, endoscopic mucosal resection, molecular biomarkers, optical coherence tomography, confocal laser endomicroscopy, volumetric laser endomicroscopy, and endocytoscopy. Treatment of BE depends on the presence of intramucosal cancer or dysplasia, particularly high-grade dysplasia with or without visible mucosal lesions.

CONCLUSIONS

Recent advances in endoscopic diagnostic tools demonstrate promising results and help to mitigate the shortcomings of the Seattle protocol. Future research as well as refining these tools may help aid them in replacing standard untargeted biopsies.

Red flag imaging in Barrett's esophagus: does it help to find the needle in the haystack?

Esophageal Adenocarcinoma (EAC) has suffered a sharp increase on its incidence for the last decades, and it is associated with a poor prognosis. Barrett's Esophagus (BE) is the most important identifiable risk factor for the progression to esophageal adenocarcinoma. The key to prevent and provide a curative treatment of esophageal adenocarcinoma is the detection and eradication of early neoplasia in patients with esophagus. Endoscopic surveillance is evolving from a blind or random four quadrant biopsies protocol (Seattle protocol) to a more targeted approach. A detailed white light examination with high-resolution endoscopy is the cornerstone for recognition of early neoplastic lesions in BE. Additional imaging modalities may enhance targeting of lesions or provide more information at a focused level. There are emerging data that some of these new modalities can increase the yield of detecting dysplasia, although its routine use has yet to be validated.

Endoscopy for diagnosis and treatment in esophageal cancers: high-technology assessment

The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on the endoscopic tools to recognize squamous cell dysplasia; confocal laser endomicroscopy for Barrett's esophagus; confocal microscopy in the cancer patient; optical coherence tomography in the assessment of subsquamous Barrett's metaplasia; endoscopic mucosal resection for high-grade dysplasia in Barrett's esophagus; HALO in the treatment of squamous dysplasia; and the use of fluorescence in situ hybridization to detect dysplasia and adenocarcinoma in patients with Barrett's esophagus.

Advances in imaging probes and optical microendoscopic imaging techniques for early in vivo cancer assessment

A new chapter in the history of medical diagnosis happened when the first X-ray technology was invented in the late 1800s. Since then, many non-invasive and minimally invasive imaging techniques have been invented for clinical diagnosis to research in cellular biology, drug discovery, and disease monitoring. These imaging modalities have leveraged the benefits of significant advances in computer, electronics, and information technology and, more recently, targeted molecular imaging. The development of targeted contrast agents such as fluorescent and nanoparticle probes coupled with optical imaging techniques has made it possible to selectively view specific biological events and processes in both in vivo and ex vivo systems with great sensitivity and selectivity. Thus, the combination of targeted molecular imaging probes and optical imaging techniques have become a mainstay in modern medicinal and biological research. Many promising results have demonstrated great potentials to translate to clinical applications. In this review, we describe a discussion of employing imaging probes and optical microendoscopic imaging techniques for cancer diagnosis.

In vivo endomicroscopy improves detection of Barrett's esophagus-related neoplasia: a multicenter international randomized controlled trial (with video)

BACKGROUND

Confocal laser endomicroscopy (CLE) enables in vivo microscopic imaging of the GI tract mucosa. However, there are limited data on endoscope-based CLE (eCLE) for imaging Barrett's esophagus (BE).

OBJECTIVE

To compare high-definition white-light endoscopy (HDWLE) alone with random biopsy (RB) and HDWLE + eCLE and targeted biopsy (TB) for diagnosis of BE neoplasia.

DESIGN

Multicenter, randomized, controlled trial.

SETTING

Academic medical centers.

PATIENTS

Adult patients with BE undergoing routine surveillance or referred for early neoplasia.

INTERVENTION

Patients were randomized to HDWLE + RB (group 1) or HDWLE + eCLE + TB (group 2). Real-time diagnoses and management plans were recorded after HDWLE in both groups and after eCLE in group 2. Blinded expert pathology diagnosis was the reference standard.

MAIN OUTCOME MEASUREMENTS

Diagnostic yield, performance characteristics, clinical impact.

RESULTS

A total of 192 patients with BE were studied. HDWLE + eCLE + TB led to a lower number of mucosal biopsies and higher diagnostic yield for neoplasia (34% vs 7%; P < .0001), compared with HDWLE + RB but with comparable accuracy. HDWLE + eCLE + TB tripled the diagnostic yield for neoplasia (22% vs 6%; P = .002) and would have obviated the need for any biopsy in 65% of patients. The addition of eCLE to HDWLE increased the sensitivity for neoplasia detection to 96% from 40% (P < .0001) without significant reduction in specificity. In vivo CLE changed the treatment plan in 36% of patients.

LIMITATIONS

Tertiary-care referral centers and expert endoscopists limit generalizability.

CONCLUSION

Real-time eCLE and TB after HDWLE can improve the diagnostic yield and accuracy for neoplasia and significantly impact in vivo decision making by altering the diagnosis and guiding therapy. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT01124214.).

Endomicroscopy in Barrett's esophagus

Barrett's esophagus has been a focus of confocal laser endomicroscopy (CLE) research. There are two CLE systems available, one probe-based and the other with a microscope embedded in the tip of an endoscope. Several CLE image classification systems are available. Studies suggest that CLE has good sensitivity, negative predictive value, and accuracy for detecting neoplasia, with good interobserver agreement using the CLE image classification systems. Larger, multicenter studies have been completed evaluating the impact of CLE on treatment of patients with BE. Future developments may include more specific contrast agents and new types of endomicroscopes.

Confocal laser endomicroscopy for in vivo diagnosis of Barrett's oesophagus and associated neoplasia: a pilot study conducted in a single Italian centre

BACKGROUND

Diagnosis and management of Barrett's oesophagus are controversial. Technical improvements in real-time recognition of intestinal metaplasia and neoplastic foci provide the chance for more effective target biopsies. Confocal laser endomicroscopy allows to analyze living cells during endoscopy.

AIMS

To assess the diagnostic accuracy, inter- and intra-observer variability of endomicroscopy for detecting in vivo neoplasia (dysplasia and/or early neoplasia) in Barrett's oesophagus.

METHODS

Prospective pilot study. Patients referred for known Barrett's oesophagus were screened. Endomicroscopy was carried out in a circular fashion, every 1-2 cm, on the whole columnar-lined distal oesophagus. Visible lesions, when present, were analyzed first. Targeted biopsies were taken. Confocal images were classified according to confocal Barrett classification. Endomicroscopic and histological findings were compared.

RESULTS

Forty-eight out of 50 screened patients underwent endomicroscopy. Visible lesions were observed in 3 patients. In a per-biopsy analysis, Barrett's-oesophagus-associated neoplasia could be predicted with an accuracy of 98.1%. The agreement between endomicroscopic and histological results was substantial (κ=0.76).

CONCLUSIONS

This study suggests that endomicroscopy can provide in vivo diagnosis of Barrett's oesophagus-associated neoplasia. Because it allows for the study of larger surface areas of the mucosa, endomicroscopy may lead to significant improvements in the in vivo screening and surveillance of Barrett's oesophagus.

Confocal Laser Endomicroscopy for Diagnosis of Barrett's Esophagus

Barrett’s esophagus (BE) is established as a premalignant condition in the distal esophagus. Current surveillance guidelines recommend random biopsies every 1–2 cm at intervals of 3–5 years. Advanced endoscopic imaging of BE underwent several technical revolutions within the last decade including broad-field (red-flag) techniques (e.g., chromoendoscopy) and small-field techniques with confocal laser endomicroscopy (CLE) at the forefront. In this review we will focus on advanced endoscopic imaging using CLE for the diagnosis and characterization of BE and associated neoplasia. In addition, we will critically discuss the technique of CLE and provide some tricks and hints for the daily routine practice of CLE for diagnosis of BE.

Endoscopic Imaging in Barrett's Oesophagus: Applications in Routine Clinical Practice and Future Outlook

The practice for endoscopic surveillance of Barrett's oesophagus has evolved from "blind" or random 4 quadrant biopsies (Seattle protocol) to a more "intelligent" targeted biopsy approach. This evolution has been possible due to the rapid advances in endoscopic imaging technology and expertise in the last decade. Previous endoscopes had relatively poor image resolution that often did not allow the subtle mucosal changes associated with dysplastic Barrett's mucosa to be identified. Newer endoscopic imaging techniques available today may allow endoscopists to identify areas of dysplasia or malignancy and target biopsies accordingly. These modalities which include narrow band imaging, chromoendoscopy, autofluorescence imaging, and confocal endomicroscopy as well as a few novel imaging modalities on the horizon will be discussed further.

Endomicroscopy in the evaluation of Barrett's esophagus

PURPOSE OF REVIEW

Confocal laser endomicroscopy (CLE) can provide real-time, microscopic visualization of the gastrointestinal mucosa, allowing an endoscopic approach to the histologic evaluation of Barrett's esophagus and Barrett's esophagus-associated neoplasia.

RECENT FINDINGS

Both endoscope-based (eCLE) and probe-based (pCLE) CLE systems have been used to evaluate Barrett's esophagus and Barrett's esophagus-associated neoplasia. Criteria for distinguishing Barrett's esophagus with neoplasia from nondysplastic Barrett's esophagus have been developed and validated for both eCLE and pCLE. Several studies have shown excellent detection of Barrett's esophagus neoplasia by CLE, and the technique may be used to guide endoscopic therapy. Advanced endomicroscopy systems and peptides and antibodies that target neoplasia are in development.

SUMMARY

CLE has provided a new way of evaluating Barrett's esophagus and Barrett's esophagus-associated neoplasia and is being used to improve detection and management of neoplasia in Barrett's esophagus.

Endomicroscopy of Barrett's Esophagus

Endomicroscopy is a remarkable technical advance in gastrointestinal mucosa imaging. In 2003, Kiesslich and colleagues described the first human use of contrast-aided confocal laser endomicroscopy (CLE) as a novel technique for in vivo microscopic imaging of the gastrointestinal mucosa. Both probe-based and endoscope-based systems have been applied to many gastrointestinal disorders, including Barrett's esophagus (BE) and associated neoplasia. Probe-based confocal laser endomicroscopy can be used in conjunction with highresolution white light endoscopy and other contrast enhancement techniques. It has proven high accuracy for prediction of high-grade neoplasia and cancer. In vivo imaging of both flat BE and mucosal lesions can influence diagnosis and thereby impact upon decision making regarding tissue sampling and endoscopic therapy. This article discusses the scientific literature related to clinical use of CLE for BE, the techniques for performing CLE in the esophagus, and the potential future directions for CLE in BE and esophageal cancer diagnosis and treatment.

Endoscopic techniques for recognizing neoplasia in Barrett's esophagus: which should the clinician use?

PURPOSE OF REVIEW

The key to prevention and cure of esophageal adenocarcinoma is the detection and eradication of neoplasia in patients with Barrett's esophagus. Multiple tools and technologies are emerging for this purpose.

RECENT FINDINGS

A detailed white light examination with high-resolution endoscopy and recognition of lesions is paramount. A variety of imaging modalities are being studied for the detection of neoplasia in Barrett's esophagus. Chromoendoscopy, narrow band imaging, and autofluorescence provide a way to target suspicious areas. Confocal endomicroscopy and optical coherence tomography are means to pinpoint imaging to obtain information about the tissue microarchitecture.

SUMMARY

The key to detection of neoplasia is a careful white light examination with high-resolution endoscopy and recognition of lesion characteristics. Additional imaging modalities may enhance targeting of lesions or provide more information at a focused level. Many of these modalities have yet to be validated in prospective randomized, multicenter trials.

Confocal laser endomicroscopy: potential in the management of Barrett's esophagus

Confocal laser endomicroscopy (CLE) can serve as a useful adjunct imaging modality for targeted endoscopic biopsies during surveillance of Barrett's esophagus (BE). In addition, CLE may also have potential roles during therapeutic procedures that include localization of pathology, targeting of resections, guiding which therapy to use, and determining adequacy of treatment. This case series illustrates a range of cases in which endomicroscopy was performed during the procedure and offers possibilities of real-time decision-making to select specific therapies in patients with known high-grade dysplasia (HGD) and intramucosal carcinoma in the setting of BE presented for endoscopic treatment or follow-up. Patients with BE with HGD and intramucosal carcinoma presented for management for initial treatment or follow-up. Examinations were performed sequentially with detailed white light endoscopy, narrow band imaging (NBI), acetic acid, and CLE. This is a retrospective case series describing the characteristics of the exam findings and illustrating the role of endomicroscopy on real-time case management. Seven patients with Barrett-associated neoplasia underwent endomicroscopy as part of their endoscopic examination. CLE confirmed findings of neoplasia seen with red flag techniques such as NBI, and in one case independently suggested findings of neoplasia. In the majority of cases, these findings were incorporated into the decision of which modality of treatment was used. Future prospective studies should be done to validate the role of endomicroscopy in BE.

Optimal endoluminal treatment of Barrett's esophagus: integrating novel strategies into clinical practice

Endoluminal therapy has become the first-choice treatment over the last 5 years for early Barrett's neoplasia limited to the mucosa. Long-term follow-up data on endoscopic resection have demonstrated the oncological safety of endoscopic resection in comparison to surgery. However, there is a high rate of recurrent disease, which can be avoided using additional ablation of the remaining Barrett. Radiofrequency ablation was recently introduced as an efficacious means to ablate Barrett's epithelium with a better safety profile than older ablation techniques. Recent studies show that endoscopic resection can be safely combined with radiofrequency ablation for treating dysplastic Barrett's after removal of visible lesions. This constitutes a completely new treatment paradigm that will be integrated in routine clinical practice in the forthcoming years.

New Endoscopic Techniques: Challenges and Opportunities for Surgical Pathologists

In recent years, significant clinical and technological advances have been made in endoscopic methods for diagnosis and treatment of early gastrointestinal neoplasms. However, essential information related to these novel techniques and their implications for practicing surgical pathologists have largely been missing in the general pathology literature. This article provides a general introduction to these novel therapeutic and diagnostic methods, and discusses their indications, contraindications, and potential limitations. The article aims to enable surgical pathologists to interact more efficiently with basic scientists and clinical colleagues to help implement and improve the existing clinical methods and to advance the new technologies.

In vivo high-resolution fluorescence microendoscopy for ovarian cancer detection and treatment monitoring

Background:

In patients with advanced ovarian cancer (OvCa), microscopic residual tumour nodules that remain after surgical debulking frequently escape detection by current treatment assessment methods and lead to disease recurrence. The aim of this study was to evaluate the use of high-resolution fibre-optic fluorescence imaging of the clinically approved photodynamic therapy (PDT) agent benzoporphyin-derivative monoacid ring A (BPD-MA) for detection of microscopic OvCa and for monitoring treatment response.

Methods:

Our fluorescence microendoscope consists of a flexible imaging fibre coupled to a custom epi-fluorescence system optimised for imaging BPD-MA, which, after a single administration, serves as both an imaging agent and a light-activated therapeutic agent. After characterisation in an in vitro OvCa 3D model, we used the flexible imaging fibre to minimally invasively image the peritoneal cavity of a disseminated OvCa murine model using BPD-MA administered intraperitoneally (i.p.). To evaluate longitudinal changes in response to treatment, we compared sets of images obtained before and after PDT with those from untreated mice imaged at the same time points.

Results:

By comparison with histopathology, we report an 86% sensitivity for tumour detection in vivo using the microendoscope. Using a custom routine to batch process-image data in the monitoring study, treated mice exhibited an average decrease of 58.8% in tumour volumes compared with an increase of 59.3% in untreated controls (P<0.05).

Conclusions:

Our findings indicate the potential of this approach as a reporter of treatment outcome that could aid in the rational design of strategies to mitigate recurrent OvCa.

Confocal laser endomicroscopy in Barrett's esophagus and endoscopically inapparent Barrett's neoplasia: a prospective, randomized, double-blind, controlled, crossover trial

BACKGROUND

The detection of high-grade dysplasia and cancer in Barrett's esophagus (BE) can be challenging. Confocal laser endomicroscopy (CLE) allows in vivo visualization of mucosal histology during endoscopy.

OBJECTIVE

To determine whether CLE with optical biopsy and targeted mucosal biopsy improves the diagnostic yield of endoscopically inapparent, BE-associated neoplasia compared to standard endoscopy with a 4-quadrant, random biopsy protocol.

DESIGN

Prospective, double-blind, randomized, crossover study.

SETTING

Single, tertiary-care academic center.

PATIENTS

This study involved patients with BE undergoing routine surveillance or referred for treatment of nonlocalized, endoscopically inapparent, BE-associated neoplasia.

INTERVENTION

All participants underwent both a confocal endomicroscopy with a targeted biopsy procedure and standard endoscopy with a 4-quadrant biopsy procedure in a randomized order.

MAIN OUTCOME MEASUREMENTS

Increase in diagnostic yield for neoplasia, reduction in mucosal biopsy number, final pathologic diagnosis.

RESULTS

CLE with targeted biopsy almost doubled the diagnostic yield for neoplasia and was equivalent to the standard protocol for the final diagnosis of neoplasia. Two thirds of patients in the surveillance group did not need any mucosal biopsies at all.

LIMITATION

Single-center study.

CONCLUSION

CLE with targeted biopsy significantly improves the diagnostic yield for endoscopically inapparent BE neoplasia compared to a standard endoscopy with a random-biopsy protocol. CLE with targeted biopsy also greatly reduces the number of biopsies needed per patient and allows some patients without neoplasia to completely forgo mucosal biopsy.