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

Artificial intelligence-aided optical biopsy improves the diagnosis of esophageal squamous neoplasm

BACKGROUND

Early detection of esophageal squamous neoplasms (ESN) is essential for improving patient prognosis. Optical diagnosis of ESN remains challenging. Probe-based confocal laser endomicroscopy (pCLE) enables accurate in vivo histological observation and optical biopsy of ESN. However, interpretation of pCLE images requires histopathological expertise and extensive training. Artificial intelligence (AI) has been widely applied in digestive endoscopy; however, AI for pCLE diagnosis of ESN has not been reported.

AIM

To develop a pCLE computer-aided diagnostic system for ESN and assess its diagnostic performance and assistant efficiency for nonexpert endoscopists.

METHODS

The intelligent confocal laser endomicroscopy (iCLE) system consists of image recognition (based on inception-ResNet V2), video diagnosis, and quality judgment modules. This system was developed using pCLE images and videos and evaluated through image and prospective video recognition tests. Patients between June 2020 and January 2023 were prospectively enrolled. Expert and non-expert endoscopists and the iCLE independently performed diagnoses for pCLE videos, with histopathology as the gold standard. Thereafter, the non-expert endoscopists performed a second assessment with iCLE assistance.

RESULTS

A total of 25056 images from 2803 patients were selected for iCLE training and validation. Another 2442 images from 226 patients were used for testing. iCLE achieved a high accuracy of 98.3%, sensitivity of 95.3% and specificity of 98.8% for diagnosing ESN images. A total of 2581 patients underwent upper gastrointestinal pCLE examination and were prospectively screened; 54 patients with suspected ESN were enrolled. Overall, 187 videos from 67 lesions were assessed by iCLE, three nonexpert and three expert endoscopists. iCLE achieved a high accuracy, sensitivity and specificity of 90.9%, 92.0%, and 90.2%, respectively. Compared to experts, iCLE showed significantly higher sensitivity (92.0% vs 80.4%; P < 0.001) and negative predictive value (94.4% vs 87.7%; P = 0.003). With iCLE assistance, nonexpert endoscopists showed significant improvements in accuracy (from 83.6% to 88.6%) and sensitivity (from 76.0% to 89.8%).

CONCLUSION

iCLE system demonstrated high diagnostic performance for ESN. It can assist nonexpert endoscopists in improving the diagnostic efficiency of pCLE for ESN and has the potential for reducing unnecessary biopsies.

Effect of computer aided detection system on esophageal neoplasm diagnosis in varied levels of endoscopists

A computer-aided detection (CAD) system for early esophagus carcinoma identification during endoscopy with narrow-band imaging (NBI) was evaluated in a large-scale, prospective, tandem, randomized controlled trial to assess its effectiveness. The study was registered at the Chinese Clinical Trial Registry (ChiCTR2100050654, 2021/09/01). Involving 3400 patients were randomly assigned to either routine (routine-first) or CAD-assisted (CAD-first) NBI endoscopy, followed by the other procedure, with targeted biopsies taken at the end of the second examination. The primary outcome was the diagnosis of 1 or more neoplastic lesion of esophagus during the first examination. The CAD-first group demonstrated a significantly higher neoplastic lesion detection rate (3.12%) compared to the routine-first group (1.59%) with a relative detection ratio of 1.96 (P = 0.0047). Subgroup analysis revealed a higher detection rate in junior endoscopists using CAD-first, while no significant difference was observed for senior endoscopists. The CAD system significantly improved esophageal neoplasm detection, particularly benefiting junior endoscopists.

Surgical polarimetric endoscopy for the detection of laryngeal cancer

The standard-of-care for the detection of laryngeal pathologies involves distinguishing suspicious lesions from surrounding healthy tissue via contrasts in colour and texture captured by white-light endoscopy. However, the technique is insufficiently sensitive and thus leads to unsatisfactory rates of false negatives. Here we show that laryngeal lesions can be better detected in real time by taking advantage of differences in the light-polarization properties of cancer and healthy tissues. By measuring differences in polarized-light retardance and depolarization, the technique, which we named 'surgical polarimetric endoscopy' (SPE), generates about one-order-of-magnitude greater contrast than white-light endoscopy, and hence allows for the better discrimination of cancerous lesions, as we show with patients diagnosed with squamous cell carcinoma. Polarimetric imaging of excised and stained slices of laryngeal tissue indicated that changes in the retardance of polarized light can be largely attributed to architectural features of the tissue. We also assessed SPE to aid routine transoral laser surgery for the removal of a cancerous lesion, indicating that SPE can complement white-light endoscopy for the detection of laryngeal cancer.

The development and clinical application of microscopic endoscopy for in vivo optical biopsies: Endocytoscopy and confocal laser endomicroscopy

Endoscopies are crucial for detecting and diagnosing diseases in gastroenterology, pulmonology, urology, and other fields. To accurately diagnose diseases, sample biopsies are indispensable and are currently considered the gold standard. However, random 4-quadrant biopsies have sampling errors and time delays. To provide intraoperative real-time microscopic images of suspicious lesions, microscopic endoscopy for in vivo optical biopsy has been developed, including endocytoscopy and confocal laser endomicroscopy. This article reviews recent advances in technology and clinical applications, as well as their shortcomings and future directions.

Confocal laser endomicroscopy in gastro-intestinal endoscopy: technical aspects and clinical applications

Confocal laser endomicroscopy (CLE) is an advanced endoscopic imaging technology that provides a magnified, cellular level view of gastrointestinal epithelia. In conjunction with topical or intravenous fluorescent dyes, CLE allows for an "optical biopsy" for real-time diagnosis. Two different CLE system have been used in clinical endoscopy, probe-based CLE (pCLE) and endoscope-based CLE (eCLE). Using pCLE, the device can be delivered: (I) into the luminal gastrointestinal tract through the working channel of standard endoscopes; (II) into extraluminal cystic and solid parenchymal lesions through an endoscopic ultrasound (EUS) needle; or (III) into the biliary system through an endoscopic retrograde cholangiopancreatography (ERCP) accessory channel. With eCLE, the probe is directly integrated into the tip of a conventional endoscope, however, these endoscopes are no longer commercially available. CLE has moderate to high diagnostic accuracy for neoplastic and inflammatory conditions through the gastrointestinal tract including: oesophageal, gastric and colonic neoplasia, pancreatic cysts and solid lesions, malignant pancreatobiliary strictures and inflammatory bowel disease. Some studies have demonstrated the diagnostic benefit of CLE imaging when combined with either conventional white light endoscopy or advanced imaging technologies. Therefore, optical biopsies using CLE can resolve diagnostic dilemmas in some cases where conventional imaging fails to achieve conclusive results. CLE could also reduce the requirement for extensive tissue sampling during surveillance procedures. In the future, CLE in combination with molecular probes, could allow for the molecular characterization of diseases and assess response to targeted therapy. However, the narrow field of view, high capital costs and specialized operator training requirements remain the main limitations. Future multi-center, randomized trials with a focus on conventional diagnostic applications, cost-effectiveness and standardized training will be required for definitive evidence. The objective of this review is to evaluate the technical aspects and current applications of CLE in patients with gastrointestinal and pancreatobiliary diseases and discuss future directions for this technique.

Diagnostic yield of fourth-generation endocytoscopy for esophageal squamous lesions using a modified endocytoscopic classification

OBJECTIVES

Endocytoscopy (EC) is an ultra-high magnification endoscopy designed to provide in vivo histologic assessment. This study aimed to evaluate the diagnostic yield of the newly developed fourth-generation EC for esophageal squamous lesions by using a modified EC classification.

METHODS

A total of 2548 EC images of 57 esophageal targeted areas between June 2015 and October 2017 were retrospectively collected. Two lesions with low-quality images were excluded. Only EC images were independently reviewed by two expert and two non-expert endoscopists. The lesions were classified according to a three-tier modified EC classification. We used a multilevel logistic regression to analyze the data.

RESULTS

The sensitivity and specificity of diagnosing non-squamous cell cancer (SCC) vs SCC were 82.5% and 83.0% by the experts; 90.1% and 75.0% by non-experts. The interobserver agreement among the four raters was good (kappa statistic 0.59). The diagnostic accuracy of experts and non-experts was similar (P = 0.16 for specificity and P = 0.20 for sensitivity). The sensitivity and specificity of EC for non-neoplasia vs neoplasia were 88.7% and 74.6% by experts; 90.3 and 52.1% by non-experts. The interobserver agreement among the four raters was moderate (kappa statistic 0.44). The specificity of experts was higher compared to non-experts, although the difference did not reach statistical significance (P = 0.08 for specificity and P = 0.93 for sensitivity).

CONCLUSIONS

Fourth-generation EC offers acceptable diagnostic accuracy and reliability in both experts and non-experts, especially when diagnosing SCC lesions.

Diagnosis of Clinical Complete Response by Probe-Based Confocal Laser Endomicroscopy (pCLE) After Chemoradiation for Advanced Rectal Cancer

BACKGROUND

Neoadjuvant chemoradiotherapy (nCRxt) followed by radical surgery is the optimal treatment for advanced rectal adenocarcinoma. Patients with clinical complete response (cCR) may be followed closely without immediate surgery. Probe-based confocal laser endomicroscopy (pCLE) is a real-time in vivo method that allows acquisition of optical biopsies with 1000 times magnification, evaluating both epithelial and vascular patterns.

AIM

To evaluate the role of pCLE in the diagnosis of cCR after nCRxt for advanced rectal adenocarcinoma.

METHODS

pCLE was performed in 47 patients with locally advanced rectal adenocarcinoma (T3/T4, or N+) who underwent nCRxt (5-fluorouracil, 5040 cGy).

RESULTS

Twenty-seven (57.5%) patients were men, and the mean age was 62.8 years. Thirty-seven had partial response confirmed by pCLE. Ten (21.3%) patients had good endoscopic response and presented small ulcer (n = 5) or residual scar (n = 5). After nCRxt, the essential features to differentiate malignancy from post-radiation alterations at pCLE were the presence of irregular crypts, budding, back-to-back glands, cribriform pattern, increased vessel/crypt ratio, and fluorescein leakage. A scoring system was created considering these epithelial and vascular features, with high accuracy for differentiating patients with complete response from those with residual neoplasia (p < 0.00001). pCLE sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 100%, 71.4%, 95.2%, 100%, and 95.7%, respectively.

CONCLUSIONS

(1) pCLE evaluation of epithelial and vascular features may improve the diagnosis of cCR and may alter patient management; (2) pCLE might be valuable for identifying patients with advanced rectal cancer who will benefit from watch and wait strategy, avoiding immediate surgical treatment.

Pediatric dysphonia: It's not about the nodules

OBJECTIVE

Despite the fact that vocal nodules are the most common cause of chronic dysphonia in children, uncertainty and lack of consensus complicates practically every diagnostic and management decision. Selecting an optimal staging system is fundamental to understanding a disease process, mandatory for uniform reporting, and crucial to predicting natural history and treatment outcomes. The ideal prognostic model for vocal nodules is under intense debate. The purpose of this study was to analyze the predictive power of vocal nodule grade to severity of voice metrics in children.

METHODS

Seventy-nine patients diagnosed with vocal cord nodules between 2006 and 2012 were drawn from UPMC Children's Hospital of Pittsburgh Voice, Resonance and Swallowing Center Research Registry. Subject age at time of diagnosis, nodule grade, relevant co-morbidities, scores on The Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V), parent-reported Pediatric Voice Handicap Index (pVHI), the phonotraumatic behaviors profile, habitual speaking pitch fundamental frequencies, pitch range, volume intensity, and s/z ratio were recorded and compiled into a de-identified database for analysis.

RESULTS

Based on the Kruskal-Wallis H Test, there was no statistically significant correlation between nodule grade and total pitch range (p = .21), s/z ratio (p = .50), volume intensity (p = .33), overall CAPE-V Scores (p = .15), or pVHI Scores (p = .29). Chi-squared tests also revealed no significant associations between nodule grade and abnormality in habitual speaking pitch (p = .14 for fundamental frequency while sustaining a vowel sound, p = .37 for fundamental frequency while speaking structured tasks i.e. counting, or p = .76 while speaking in conversation).

CONCLUSION

The current "gold-standard" for grading vocal nodule size suggests that the nodules themselves are not driving the standard dysphonic metrics that are most commonly collected and monitored in such children. This outcome is consistent with other studies reporting similar findings and was expected based on the inconsistencies in the reported literature to date. By extension, the conventional wisdom of avoiding surgical treatment of vocal nodules in children seems prudent as there is little evidence to suggest that the nodules themselves are "driving" the severity of the dysphonia. Ultimately identifying the true "drivers" of dysphonia in children will suggest alternative therapies that are more specific and directed to the pathophysiology. Most pediatric voice care professionals will welcome such discoveries as those in the front line of patient care are often rendered helpless and frustrated.

Artificial intelligence and upper gastrointestinal endoscopy: Current status and future perspective

With recent breakthroughs in artificial intelligence, computer-aided diagnosis (CAD) for upper gastrointestinal endoscopy is gaining increasing attention. Main research focuses in this field include automated identification of dysplasia in Barrett's esophagus and detection of early gastric cancers. By helping endoscopists avoid missing and mischaracterizing neoplastic change in both the esophagus and the stomach, these technologies potentially contribute to solving current limitations of gastroscopy. Currently, optical diagnosis of early-stage dysplasia related to Barrett's esophagus can be precisely achieved only by endoscopists proficient in advanced endoscopic imaging, and the false-negative rate for detecting gastric cancer is approximately 10%. Ideally, these novel technologies should work during real-time gastroscopy to provide on-site decision support for endoscopists regardless of their skill; however, previous studies of these topics remain ex vivo and experimental in design. Therefore, the feasibility, effectiveness, and safety of CAD for upper gastrointestinal endoscopy in clinical practice remain unknown, although a considerable number of pilot studies have been conducted by both engineers and medical doctors with excellent results. This review summarizes current publications relating to CAD for upper gastrointestinal endoscopy from the perspective of endoscopists and aims to indicate what is required for future research and implementation in clinical practice.

Probe-based confocal laser endomicroscopy for diagnosis of nasopharyngeal carcinoma in vivo

OBJECTIVES/HYPOTHESIS

Probe-based confocal laser endomicroscopy (pCLE) is a novel technique allowing real-time evaluation of the histological features of tissues in vivo at the cellular level. This study aimed to evaluate the feasibility of using pCLE in the diagnosis of nasopharyngeal carcinoma (NPC).

STUDY DESIGN

Feasibility study.

METHODS

In this study, the pCLE images of the lesions, as well as the surrounding or contralateral normal mucosa of the lesions, were acquired in vivo from each patient after intravenous injecting of 2.5 mL fluorescein. Biopsy specimens were collected at the imaged sites followed by a histopathological diagnosis by the pathologists, which was used as the gold standard. The pCLE images were compared to histopathological diagnosis of visualized sites by using sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV).

RESULTS

Diagnoses based on pCLE images correlated well with the gold standard diagnoses based on tissue histology. The overall sensitivity, specificity, PPV, and NPV for diagnosis of carcinoma versus nondysplasia were 93.8% (67.7%-99.7%), 90.5% (68.2%-98.3%), 88.2% (62.3%-97.9%), and 95.0% (73.1%-99.7%), respectively, and the four indices for pCLE diagnosis of dysplasia versus nondysplasia were 60.0% (17.0%-92.7%), 80.9% (57.4%-93.7%), 42.9% (11.8%-79.8%), and 89.5% (65.5%-98.2%), respectively. The overall sensitivity for diagnosis of carcinoma versus dysplasia was 93.8% (67.7%-99.7%), specificity was 40% (7.3%-83.0%), PPV was 83.3% (57.7%-95.6%), and the NPV was 66.7% (12.5%-98.2%).

CONCLUSIONS

CLE is a suitable and valid method for otolaryngologists to diagnose of NPC in vivo.

LEVEL OF EVIDENCE

NA Laryngoscope, 129:897-902, 2019.

Probe-based confocal endomicroscopy is accurate for differentiating gastric lesions in patients in a Western center

Objective

Probe-based confocal laser endomicroscopy (pCLE) technique may improve the diagnosis of gastric mucosal lesions allowing acquisition of high-resolution in vivo images at the cellular and microvascular levels. This study aims to evaluate the accuracy of pCLE for the differential diagnosis of non-neoplastic and neoplastic gastric lesions.

Methods

Twenty gastric mucosal lesions from 10 patients were evaluated during endoscopic procedure and were examined by pCLE. Diagnostic pCLE was followed by biopsies or endoscopic resection of suspected lesions. A senior pathologist evaluated the specimens and was blinded to the pCLE results.

Results

Patients' mean age was 68.3 (range, 42-83) years and six were men. Thirteen suspicious flat or elevated lesions (classified as 0-Is, 0-IIa or 0-IIa + IIc) and seven pre-malignant lesions (atrophy and intestinal metaplasia) were evaluated. One patient was studied during his long-term follow-up after partial gastrectomy and presented severe atrophy, intestinal metaplasia, and xanthomas at the stump mucosa. The location of gastric lesions was in the body (n=10 lesions), the antrum (n=9) and the incisura angularis (n=1). All neoplastic lesions and all but one benign lesion were properly diagnosed by pCLE. pCLE incorrectly diagnosed one small antrum lesion as adenoma, however the final diagnosis was intestinal metaplasia. The final histological diagnosis was neoplastic in 9 and benign lesions in 11. In this small case series, pCLE accuracy was 95% (19/20 lesions).

Conclusions

pCLE is accurate for real time histology of gastric lesions. pCLE may change the management of patients with gastric mucosal lesions, guiding biopsies and endoscopic resection, and avoiding further diagnostic workup or unnecessary therapy.

Endoscopic Management of Early Adenocarcinoma and Squamous Cell Carcinoma of the Esophagus: Screening, Diagnosis, and Therapy

Because the esophagus is easily accessible with endoscopy, early diagnosis and curative treatment of esophageal cancer is possible. However, diagnosis is often delayed because symptoms are not specific during early stages of tumor development. The onset of dysphagia is associated with advanced disease, which has a survival at 5 years lower than 15%. Population screening by endoscopy is not cost-effective, but a number of alternative imaging and cell analysis technologies are under investigation. The ideal screening test should be inexpensive, well tolerated, and applicable to primary care. Over the past 10 years, significant progress has been made in endoscopic diagnosis and treatment of dysplasia (squamous and Barrett's), and early esophageal cancer using resection and ablation technologies supported by evidence from randomized controlled trials. We review the state-of-the-art technologies for early diagnosis and minimally invasive treatment, which together could reduce the burden of disease.