Narrow band imaging: a new diagnostic approach to visualize angiogenesis in superficial neoplasia

Serum midkine as a biomarker for malignancy, prognosis, and chemosensitivity in head and neck squamous cell carcinoma

Improved therapies for individuals with head and neck squamous cell carcinoma (HNSCC) may be developed by identification of appropriate biomarkers. The aim of this study was to evaluate the usefulness of serum midkine measurement as a biomarker for HNSCC. Pretreatment serum midkine concentrations were measured in 103 patients with HNSCC and 116 control individuals by enzyme‐linked immunosorbent assay. Midkine expression in tumor tissues from 33 patients with HNSCC who underwent definitive surgical resection without preoperative treatment was examined by immunohistochemistry. The cut‐off serum midkine concentrations for predicting the presence of head and neck malignancy and chemosensitivity to induction chemotherapy, as determined using receiver operating characteristic curves, were 482 and 626 pg/mL, respectively. Spearman bivariate correlations showed positive correlations between serum midkine levels and immunohistochemistry staining score (r = 0.612, P < 0.001). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of serum midkine concentration for detection of HNSCC were 57.3, 85.3, 77.6, 69.2, and 72.1%, respectively. However, for predicting the response to induction chemotherapy, the values were 84.6, 60.9, 71.0, 77.8, and 73.5%, respectively. Serum midkine concentration was identified as an independent prognostic factor by multivariate analysis, using Cox's proportional hazards model (P = 0.027). Overexpression of serum midkine yielded a relative risk of death of 3.77, with 95% confidence limits ranging from 1.15 to 17.0. Serum midkine levels in patients with HNSCC were associated with malignancy, chemosensitivity, and prognosis. Serum midkine may be a useful, minimally invasive biomarker for early detection, therapeutic decision‐making, and predicting prognosis.

White globe appearance is a novel specific endoscopic marker for gastric cancer: A prospective study

BACKGROUND AND AIM

White globe appearance (WGA) is a small white lesion with a globular shape that can be identified by magnifying endoscopy with narrow-band imaging (M-NBI). WGA was recently reported as a novel endoscopic marker that can differentiate between gastric cancer (GC) and low-grade adenoma. However, the usefulness of WGA for differentiating GC from non-cancerous lesions (NC), including those of gastritis, is unknown.

METHODS

To compare the prevalence of WGA in GC and NC, we carried out a prospective study of 994 patients undergoing gastroscopy. All patients were examined for target lesions that were suspected to be GC. When a target lesion was detected, the presence or absence of WGA in the lesion was evaluated using M-NBI, and all target lesions were biopsied or resected for histopathological diagnosis. Primary endpoint was a comparison of WGA prevalence in GC and NC. Secondary endpoints included WGA diagnostic performance for diagnosing GC.

RESULTS

A total of 188 target lesions from 156 patients were analyzed for WGA, and histopathological diagnoses included 70 cases of GC and 118 cases of NC. WGA prevalence in GC and NC was 21.4% (15/70) and 2.5% (3/118), respectively (P < 0.001). WGA diagnostic accuracy, sensitivity, and specificity for detecting GC were 69.1%, 21.4%, and 97.5%, respectively.

CONCLUSIONS

WGA prevalence in GC is significantly higher than that in NC. Because WGA is highly specific for GC, the presence of WGA is useful to diagnose GC.

A significant feature of microvessels in magnifying narrow-band imaging for diagnosis of early gastric cancer

BACKGROUND AND STUDY AIMS

Magnifying narrow-band imaging (NBI) is more useful than conventional endoscopy for diagnosing early gastric cancer (EGC). However, evaluation of irregular microvascular patterns is subjective and is often difficult, even with expert eyes. The aim of this study was to clarify the most important microvascular patterns in magnifying NBI for diagnosis of EGC.

PATIENTS AND METHODS

This was a post-hoc analysis of a multicenter prospective trial among nine Japanese hospitals. A total of 1353 patients underwent screening with white-light endoscopy and 362 patients had small (≤ 10 mm) depressed lesions. They were randomly assigned to magnifying NBI or white-light endoscopy followed by magnifying NBI. During diagnosis, magnifying NBI images were recorded before biopsy. All magnifying NBI images were reviewed and evaluated for the association of four features of microvessels - that is, dilation, tortuosity, difference in caliber, and variation in shape - with cancer diagnosis.

RESULTS

Images of 343 lesions (40 cancerous and 303 benign depression lesions) were evaluable. The diagnostic performance (sensitivity/specificity) of each finding was: dilation, 25/90 %; tortuosity, 55/24 %; difference in caliber, 13 /99 %; and variation in shape, 70/95 %. Multivariate analysis identified only variation in shape as being statistically significantly associated with diagnosis of cancer (odds ratio 38.0, 95 % confidence interval: 16.1 - 95.7, P < 0.001). All findings showed moderate agreement (κ values): dilation, 0.44; tortuosity, 0.33; difference in caliber, 0.26; and variation in shape, 0.48.

CONCLUSIONS

A variation in shape was the most significant feature of microvessels observed in magnifying NBI for diagnosis of small depressed-type EGC.

STUDY REGISTRATION

UMIN-CTR000001072.

Recent Advances From Basic and Clinical Studies of Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive squamous cell carcinomas and is highly prevalent in Asia. Alcohol and its metabolite, acetaldehyde, are considered definite carcinogens for the esophagus. Polymorphisms in the aldehyde dehydrogenase 2 gene, which encodes an enzyme that eliminates acetaldehyde, have been associated with esophageal carcinogenesis. Studies of the mutagenic and carcinogenic effects of acetaldehyde support this observation. Several recent large-scale comprehensive analyses of the genomic alterations in ESCC have shown a high frequency of mutations in genes such as TP53 and others that regulate the cell cycle or cell differentiation. Moreover, whole genome and whole exome sequencing studies have frequently detected somatic mutations, such as G:C→A:T transitions or G:C→C:G transversions, in ESCC tissues. Genomic instability, caused by abnormalities in the Fanconi anemia DNA repair pathway, is also considered a pathogenic mechanism of ESCC. Advances in diagnostic techniques such as magnifying endoscopy with narrow band imaging or positron emission tomography have increased the accuracy of diagnosis of ESCC. Updated guidelines from the National Comprehensive Cancer Network standardize the practice for the diagnosis and treatment of esophageal cancer. Patients with ESCC are treated endoscopically or with surgery, chemotherapy, or radiotherapy, based on tumor stage. Minimally invasive treatments help improve the quality of life of patients who undergo such treatments. We review recent developments in the diagnosis and treatment of ESCC and advances gained from basic and clinical research.

The Past, Present, and Future of Image-Enhanced Endoscopy

Despite the remarkable progress recently made to enhance the resolution of white-light endoscopy, detection, and diagnosis of premalignant lesions, such as adenomas and subtle early-stage cancers, remains a great challenge. As for example, although chromoendoscopy, such as endoscopy using indigo carmine, is useful for the early diagnosis of subtle lesions, the technique presents various disadvantages ranging from the time required for spray application of the dye and suctioning of excess dye to the increased difficulty in identifying lesions in the presence of severe inflammation and obstruction of visual field due to the pooling of solution in depressed-type lesions. To overcome these diagnostic problems associated with chromoendoscopy, research has focused on the development of endoscopes based on new optical technologies. Several types of image-enhanced endoscopy methods have recently been presented. In particular, image-enhanced endoscopy has emerged as a new paradigm for the diagnosis of gastrointestinal disorders. Image-enhanced endoscopes provide high-contrast images of lesions by means of optical or electronic technologies, including the contrast enhancement of the mucosal surface and of blood vessels. Chromoendoscopy, narrow-band imaging, i-SCAN, and flexible spectral imaging color enhancement are representative examples of image-enhanced endoscopy discussed in this paper.

Endoscopic laryngo-pharyngeal surgery for superficial laryngo-pharyngeal cancer

BACKGROUND AND STUDY AIMS

Narrow band imaging (NBI) combined with magnifying endoscopy enables us to detect superficial laryngo-pharyngeal cancers, which are difficult to detect by standard endoscopy. Endoscopic laryngo-pharyngeal surgery (ELPS) is a technique developed to treat such lesions and the purpose of this study is to evaluate the usefulness of ELPS for superficial laryngo-pharyngeal cancer.

PATIENTS AND METHODS

Seventy five consecutive patients with 104 fresh superficial laryngo-pharyngeal cancers are included in this study. Under general anesthesia, a specially-designed curved laryngoscope was inserted to create a working space in the pharyngeal lumen. A magnifying endoscope was inserted transorally to visualize the field and a head & neck surgeon dissected the lesion using the combination of the orally-inserted curved grasping forceps and electrosurgical needle knife in both hands. The safely, functional outcomes, and oncologic outcomes of ELPS were evaluated retrospectively.

RESULTS

Median operation time per lesion was 35 min. Post-operative bleeding occurred in 3 cases and temporal subcutaneous emphysema occurred in 10 cases. No vocal fold impairment occurred after surgery. The median fasting period was 2 days and all patients except one have a normal diet with no limitations. Local recurrence occurred in 1 case, and the 3-year overall survival rate and the 3-year disease specific survival rate was 90% and 100%, respectively.

CONCLUSIONS

ELPS is a hybrid of head and neck surgery and gastrointestinal endoscopic treatment, and enjoys the merit of both procedures. ELPS makes it possible to perform minimally-invasive surgery, preserving both the swallowing and phonation functions.

The "white globe appearance" (WGA): a novel marker for a correct diagnosis of early gastric cancer by magnifying endoscopy with narrow-band imaging (M-NBI)

BACKGROUND AND STUDY AIMS

Although magnifying endoscopy with narrow-band imaging (M-NBI) is useful for the diagnosis of gastric mucosal lesions, differentiating between early cancer (EC) and low grade adenoma (LGA) remains a challenge. During M-NBI examination, we have noted the presence of a small, white lesion with a globular shape underneath cancerous gastric epithelium, and have termed this endoscopic finding the "white globe appearance" (WGA). The aim of this study was to determine whether or not the WGA could be an endoscopic marker for distinguishing EC from LGA.

METHODS

We retrospectively analyzed both the M-NBI scans and resected specimens of a total of 111 gastric lesions from 95 consecutive patients. Our main outcome was a difference in the prevalence of the WGA in EC and LGA.

RESULTS

The prevalence of the WGA in EC and LGA was 21.5 % (20 /93) and 0 % (0 /18), respectively (P = 0.039). The sensitivity, specificity, positive predictive value, and negative predictive value for differentiating between EC and LGA, according to the presence of the WGA, were 21.5, 100, 100, and 19.8 %, respectively.

CONCLUSION

A positive WGA in a suspicious lesion on M-NBI would be an adjunct to the M-NBI diagnosis of possible EC because the specificity and positive predictive value of the WGA for differentiating between EC and LGA were extremely high. The WGA could be a novel endoscopic marker for differentiating between EC and LGA.

Magnifying endoscopy with narrow band imaging to determine the extent of resection in transoral robotic surgery of oropharyngeal cancer

Transoral robotic surgery (TORS) is a less invasive treatment that is becoming popular all over the world. One of the most important factors for achieving success in TORS is the ability to determine the extent of resection during the procedure as the extent of resection in the laryngopharynx not only affects oncological outcomes but also directly affects swallowing and voice functions. Magnifying endoscopy with narrow band imaging (ME-NBI) is an innovative optical technology that provides high-resolution images and is useful in detecting early superficial pharyngeal cancers, which are difficult to detect by standard endoscopy. A 55-year-old male with superficial oropharyngeal cancer has been successfully treated by combining MB-NBI with TORS and MB-NBI was useful in determining the extent of resection. ME-NBI with TORS will make it possible to achieve a higher ratio of minimally invasive treatment in pharyngeal cancer.

Barrett's esophagus and cancer risk: how research advances can impact clinical practice

Barrett’s esophagus (BE) is the only known precursor to esophageal adenocarcinoma (EAC), whose incidence has increased sharply in the last 4 decades. The annual conversion rate of BE to cancer is significant, but small. The identification of patients at a higher risk of cancer therefore poses a clinical conundrum. Currently, endoscopic surveillance is recommended in BE patients, with the aim of diagnosing either dysplasia or cancer at early stages, both of which are curable with minimally invasive endoscopic techniques. There is a large variation in clinical practice for endoscopic surveillance, and dysplasia as a marker of increased risk is affected by sampling error and high interobserver variability. Screening programs have not yet been formally accepted, mainly due to the economic burden that would be generated by upper gastrointestinal endoscopy. Screening programs have not yet been formally accepted, mainly due to the economic burden that would be generated by widespread indication to upper gastrointestinal endoscopy. In fact, it is currently difficult to formulate an accurate algorithm to confidently target the population at risk, based on the known clinical risk factors for BE and EAC. This review will focus on the clinical and molecular factors that are involved in the development of BE and its conversion to cancer and on how increased knowledge in these areas can improve the clinical management of the disease.

Endoscopic submucosal dissection of a squamous cell carcinoma in situ in the anal canal diagnosed by magnifying endoscopy with narrow-band imaging

A 60-year-old female underwent screening colonoscopy. Narrow-band imaging (NBI) without magnification showed a 20-mm, well-demarcated brownish area located close to the dentate line of the anal canal. Conventional white-light imaging revealed an ill-defined, flat lesion with scattered reddish spots at the same site. Magnifying endoscopy with NBI (M-NBI) revealed abnormal microvessels with dilatation, tortuosity, caliber change and various shapes that were similar to the intrapapillary capillary loop patterns seen in esophageal squamous cell carcinoma in situ. Endoscopic submucosal dissection (ESD) was performed, and on histological examination, the resected specimen showed squamous cell carcinoma (SCC) in situ and clear surgical margins. Thus, NBI is an efficient method for detecting superficial SCC in the anal canal and M-NBI may be useful for determining the extent of the lesion. During screening colonoscopy, the anal region should be carefully observed using NBI, as early detection offers a greater opportunity for ESD which is a less invasive procedure.

Use of transoral endoscopy for pharyngeal examination: cross-sectional analysis

BACKGROUND AND AIM

Transoral endoscopy with narrow band imaging (NBI) is useful for identifying early-stage head and neck cancer. However, the screening capability of transoral upper gastrointestinal endoscopy has not yet been systematically evaluated. We evaluated the usefulness of transoral upper gastrointestinal endoscopy for pharyngeal examination.

METHODS

This cross-sectional study evaluated 480 patients. All endoscopic pharyngeal examinations with NBI were carried out in accordance with prescribed procedures, consisting of 10 images each and all images were assessed by a blinded reviewer. We examined the association between the diagnostic usefulness of pharyngeal examination and other factors.

RESULTS

Median subject age was 64 years (range 22-90 years), and 64% were male. Almost all patients (98%) had an Eastern Cooperative Oncology Group Performance Status of 0 or 1.Butylscopolamine bromide was given to 382 patients (80%), and a sedative was given to 460 (96%) patients. Median observation time was 74 s (range, 16-362 s), resulting in a mean of 9.0 usable images per patient. However, photographs of the right and left pyriform sinuses were consistently poor. Ordered logistic regression analysis showed that quality images were positively correlated with increased patient age.

CONCLUSIONS

Transoral endoscopic examination was possible in most patients for screening of the head and neck. However, results were poor in the pyriform sinuses, indicating that additional improvements of examination methods and instruments are needed to enhance screening accuracy.

Detection of pharyngeal cancer in the overall population undergoing upper GI endoscopy by using narrow-band imaging: a single-center experience, 2009-2012

BACKGROUND

Nonmagnifying observation by using narrow-band imaging (NBI) is useful for detecting pharyngeal lesions. Magnifying observation by using NBI can distinguish between cancerous and noncancerous lesions and is therefore useful for the early detection of pharyngeal cancer.

OBJECTIVE

To evaluate the usefulness of observation of the pharynx by using NBI in the overall population undergoing upper GI endoscopy.

DESIGN

Retrospective study.

SETTING

Single tertiary referral center.

PATIENTS

A total of 11,050 upper GI endoscopies between January 2009 and December 2012.

INTERVENTIONS

Observation of the pharynx by using NBI.

MAIN OUTCOME MEASURES

The rate of detection of pharyngeal cancer, the rates of detection according to the reason for endoscopy, and the types of cancers detected.

RESULTS

Thirty-eight cancerous lesions were detected in 29 patients (0.26%, 29/11,050). The rate of detection of pharyngeal cancer was significantly higher in patients with a history of head and neck cancer (9.7%, 3/31) or a history of esophageal cancer (3.5%, 10/282). In patients undergoing endoscopy for screening, pharyngeal discomfort, and a history of gastric cancer, the rates of detection of pharyngeal cancer were 0.11% (10/8872), 1.1% (3/265), and 0.19% (3/1600), respectively. Two patients (6.9%) were female. One had a history of esophageal cancer, and the other had pharyngeal discomfort.

LIMITATIONS

Single-center, retrospective study.

CONCLUSIONS

Observation of the pharynx by using NBI in patients with previous head and neck cancer or esophageal cancer or who have pharyngeal discomfort is very important. Moreover, pharyngeal cancer was certainly found in the male patients undergoing screening endoscopy, although the rate was lower.

Efficacy of narrow band imaging for detection and surveillance of potentially malignant and malignant lesions in the oral cavity and oropharynx: a systematic review

OBJECTIVE

Narrow band imaging (NBI) is an endoscopic technique that enhances the mucosal surface texture, and mucosal and submucosal vascular morphology. This paper systematically reviews the available literature regarding the efficacy of NBI for the detection and monitoring of potentially malignant and malignant lesions in the oral cavity and oropharynx.

METHODS

Databases searched included PubMed, EMBASE, Web of Science and Scopus (to September 2013). Additional articles were found by conducting an author publication search using PubMed and by scanning the reference lists of relevant articles. Only trials that investigated and evaluated the effectiveness of both white light (WL) and NBI for aiding the detection of only oral potentially malignant lesions, oral squamous cell carcinomas and/or oropharyngeal squamous cell carcinomas were considered for this review. Two reviewers (ANV and CSF) independently assessed retrieved articles against the criteria, and included articles underwent data extraction and risk of bias assessment.

RESULTS

Two studies, one retrospective and one prospective, met the inclusion criteria. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy for WL ranged between 56-96%, 60-100%, 33-100%, 87-99% and 66-89% respectively, whereas it was 87-96%, 94-98%, 73-96%, 97-98% and 92-97% respectively for NBI.

CONCLUSION

While more research is required to determine the full value of NBI, it has great potential in accurately aiding the detection and assessment of neoplastic lesions, and influencing how these lesions are managed.

Can flat-type brownish microlesions in the orohypopharynx be followed up without biopsy or endoscopic resection?

BACKGROUND

Narrow-band imaging (NBI) is useful for detecting superficial oropharyngeal lesions. However, the diagnostic and treatment guidelines for NBI are not established. The aim of the present study was to evaluate the treatment strategy for these microlesions.

METHODS

From October 2008 to September 2009, 68 flat-type brownish microlesions were observed in the orohypopharynx using NBI. Lesions were examined via magnifying NBI (M-NBI) and followed up without biopsy or endoscopic resection for >12 months. To clarify the characteristics, lesions were compared with the endoscopic characteristics of flat-type lesions diagnosed by biopsy and endoscopic resection as squamous cell carcinoma and high-grade intraepithelial neoplasia.

RESULTS

The average diameter of the 68 lesions was 1.6 mm (range, 0.5-5 mm). At the 1-year follow up, 19 lesions had disappeared. No size increases or morphological changes wereobserved among 49 lesions followed for >1 year. At 2 years, 10 patients had dropped out and 11 lesions had disappeared. No changes were observed among 28 lesions followed for >2 years. Of the flat-type lesions as squamous cell carcinoma and high-grade intraepithelial neoplasia, a distinct border and irregular distribution of atypical vessels were observed in all cases using M-NBI. These findings were observed in two of 68 flat-type brownish microlesions during follow up.

CONCLUSION

Although there is some possibility of squamous cell carcinoma or high-grade intraepithelial neoplasia, flat-type microlesions of ≤5 mm diameter in the orohypopharynx may be followed for up to 2 years without biopsy or endoscopic resection.

Dense-type crypt opening seen on magnifying endoscopy with narrow-band imaging is a feature of gastric adenoma

BACKGROUND

Magnifying endoscopy with narrow-band imaging (ME-NBI) can visualize crypt openings (CO) as slit-like structures in gastric epithelial neoplasia. Visualization of numerous CO is characteristic of low-grade adenoma (LGA). The aim of the present study was to investigate whether visualization of CO by ME-NBI is useful for discriminating between LGA and early gastric cancer (EGC).

PATIENTS AND METHODS

Fifty-one superficial elevated-type gastric neoplasias (10 LGA and 41 EGC) were retrospectively evaluated. The presence of CO and the number of CO were evaluated in endoscopic photos obtained at high-power endoscopic magnification by ME-NBI. The optimal cut-off value for the number of CO visualized to discriminate between LGA and EGC was determined by receiver operating characteristic curve analysis.

RESULTS

The mean number of CO visualized was significantly larger in the LGA group than in the EGC group (31.2, 95% confidence interval [CI] 16.3-46.1 vs 6.3, 95% CI 3.6-9.0; P < 0.001). When the cut-off for the number of CO visualized was set at 20, the sensitivity, specificity, and accuracy of dense-type CO for discriminating between LGA and EGC were 90.0%, 87.8%, and 88.2%, respectively.

CONCLUSION

Determining the number of CO visualized in superficial elevated-type gastric neoplasias by ME-NBI appears to be a useful method for discriminating between LGA and EGC.

An efficient diagnostic strategy for small, depressed early gastric cancer with magnifying narrow-band imaging: a post-hoc analysis of a prospective randomized controlled trial

BACKGROUND

We previously reported that magnifying narrow-band imaging (M-NBI) is a high-performance diagnostic tool for small, depressed gastric cancer. However, an efficient diagnostic strategy using endoscopic findings has not been fully elucidated.

OBJECTIVE

To identify the endoscopic findings that contribute to accurate diagnosis of small, depressed gastric cancer and to propose the ideal diagnostic approach to such lesions.

DESIGN

Post-hoc analysis of a prospective, randomized, controlled trial.

SETTING

Nine hospitals.

PATIENTS

Three hundred fifty-three patients with small, depressed gastric lesions.

INTERVENTIONS

In the M-NBI group (n = 177), cancer diagnosis was made with diagnostic criteria including a demarcation line (DL) and an irregular microvascular pattern (IMVP). In the conventional white-light imaging (C-WLI) group (n = 176), diagnostic criteria were both an irregular margin and a spiny depressed area. In the C-WLI group, M-NBI was performed after C-WLI diagnosis.

MAIN OUTCOME MEASUREMENTS

The diagnostic performance of each criterion in M-NBI alone, C-WLI, and M-NBI after C-WLI was investigated.

RESULTS

M-NBI after C-WLI ultimately showed the best diagnostic performance in each diagnostic criterion. In M-NBI after C-WLI, evaluation of DL is technically easier than that of IMVP, and DL alone had a high sensitivity (95%) and negative predictive value (99%). The IMVP in M-NBI after C-WLI had a high sensitivity and specificity (95% and 96%, respectively) for diagnosis of cancer.

LIMITATIONS

Lesions were limited to the small, depressed type.

CONCLUSIONS

For a diagnosis using M-NBI after C-WLI, identification of DL is the first step, and subsequent inspection of IMVP diagnosed by DL is an efficient strategy.

Narrow band imaging with magnification for the diagnosis of lesions in the upper gastrointestinal tract

Endoscopy plays an important role in the diagnosis and management of gastrointestinal (GI) tract disorders. Chromoendoscopy has proven to be superior to white light endoscopy for early detection of various GI lesions. This has however been fraught with problems. The use of color stains, time taken to achieve an effect and the learning curve associated with the technique has been some of the pitfalls. Narrow band imaging (NBI) particularly in combination with magnifying endoscopy may allow the endoscopist to accomplish a fairly accurate diagnosis with good histological correlation similar to results achieved with chromoendoscopy. Such enhanced detection of pre-malignant and early neoplastic lesions in the gastrointestinal tract should allow better targeting of biopsies and could ultimately prove to be cost effective. Various studies have been done demonstrating the utility of this novel technology. This article will review the impact of NBI in the diagnosis of upper gastrointestinal tract disorders.

Risk factors for second primary neoplasia of esophagus in newly diagnosed head and neck cancer patients: a case-control study

Background

The prevalence of esophageal neoplasia in head and neck (H&N) cancer patients is not low; however, routine esophageal surveillance is not included in staging of newly-diagnosed H&N cancers. We aimed to investigate the risk factors for synchronous esophageal neoplasia and the impact of endoscopy on management of H&N cancer patients.

Methods

A total of 129 newly diagnosed H&N cancer patients who underwent endoscopy with white-light imaging, narrow-band imaging (NBI) with magnifying endoscopy (ME), and chromoendoscopy with 1.5% Lugol’s solution, before definite treatment were enrolled prospectively.

Results

60 esophageal lesions were biopsied from 53 (41.1%) patients, including 11 low-grade, 14 high-grade intraepithelial neoplasia and 12 invasive carcinoma in 30 (23.3%) patients. Alcohol consumption [odds ratio (OR) 5.90, 95% confidence interval (CI) 1.23-26.44], advanced stage (stage III and IV) of index H&N cancers (OR 2.98, 95% CI 1.11-7.99), and lower body mass index (BMI) (every 1-kg/m² increment with OR 0.87, 95% CI 0.76-0.99) were independent risk factors for synchronous esophageal neoplasia. NBI with ME was the ideal screening tool (sensitivity, specificity, and accuracy of 97.3%, 94.1%, and 96.3%, respectively, for detection of dysplastic and cancerous esophageal lesions). The treatment strategy was modified after endoscopy in 20 (15.5%) patients. The number needed to screen was 6.45 (95% CI 4.60-10.90).

Conclusions

NBI-ME surveillance of esophagus should be done in newly-diagnosed H&N cancer patients, especially those with alcohol drinking, lower BMI, and advanced stage of primary tumor.

Advances in optical adjunctive AIDS for visualisation and detection of oral malignant and potentially malignant lesions

Traditional methods of screening for oral potentially malignant disorders and oral malignancies involve a conventional oral examination with digital palpation. Evidence indicates that conventional examination is a poor discriminator of oral mucosal lesions. A number of optical aids have been developed to assist the clinician to detect oral mucosal abnormalities and to differentiate benign lesions from sinister pathology. This paper discusses advances in optical technologies designed for the detection of oral mucosal abnormalities. The literature regarding such devices, VELscope and Identafi, is critically analysed, and the novel use of Narrow Band Imaging within the oral cavity is also discussed. Optical aids are effective in assisting with the detection of oral mucosal abnormalities; however, further research is required to evaluate the usefulness of these devices in differentiating benign lesions from potentially malignant and malignant lesions.

Development of a new method using narrow band imaging for taste assessment

OBJECTIVES/HYPOTHESIS

The observation of fungiform papillae is a useful objective taste examination. The purpose of this study is to develop a new method using narrow band imaging for assessment of taste function.

STUDY DESIGN

Using a narrow band imaging endoscope, we assessed the number and blood vessel morphology of fungiform papillae and compared with the gustatory threshold by the filter paper disc test.

METHODS

The number of fungiform papillae was counted in 20 mm(2) , and blood vessels in fungiform papillae were evaluated morphologically by a five-point scoring system in 11 patients who had undergone middle ear surgery. The filter taste disc test was performed simultaneously to obtain the gustatory threshold and was compared with the number and blood vessel morphology of fungiform papillae.

RESULTS

Using a narrow band imaging endoscope, we could clearly detect not only fungiform papillae but also blood vessel morphology. There was a significant correlation between the values of the number of papillae and blood vessel morphology. Moreover, these two parameters revealed a significant inverse correlation with gustatory function. As expected, both parameters on the affected side were significant lower than those on the unaffected side in patients.

CONCLUSIONS

The assessment of fungiform papillae using narrow band imaging endoscopy is easy, highly sensitive, and reliable; therefore, it might be useful as an objective examination of taste function.

LEVEL OF EVIDENCE

N/A.

Early gastric cancer and dysplasia

Since the concept of early gastric cancer was first described in Japan in 1962, its treatment has evolved from curative surgical resection to endoscopic resection, initially with polypectomy to more recently with endoscopic submucosal dissection. As worldwide experience with these endoscopic techniques evolve and gain acceptance, studies have confirmed its comparable effectiveness with historical surgical outcomes in carefully selected patients. The criteria for endoscopic resection have expanded to offer more patients improved quality of life, avoiding the morbidity and mortality associated with surgery. This article summarizes the evolutional role of endoscopic and surgical therapy in early gastric cancer.

Clinicopathological features of minute pharyngeal lesions diagnosed by narrow-band imaging endoscopy and biopsy

AIM: To evaluate the utility of magnified narrow-band imaging (NBI) endoscopy for diagnosing and treating minute pharyngeal neoplasia.

METHODS: Magnified NBI gastrointestinal examinations were performed by the first author. A magnification hood was attached to the tip of the endoscope for quick focusing. Most of the examinations were performed under sedation. Magnified NBI examinations were performed for all of the pharyngeal lesions that had noticeable brownish areas under unmagnified NBI observation, and an intrapapillary capillary loop (IPCL) classification was made. A total of 93 consecutive pharyngeal lesions were diagnosed as IPCL type IV and were suspected to represent dysplasia. Sixty-two lesions of approximately 1 mm in diameter were biopsied in the clinic, and 17 lesions with larger diameters were resected by endoscopic submucosal dissection (ESD) at the Hiroshima University Hospital. In addition to the histological diagnoses, the lesion diameters were microscopically measured in 45 of the 62 biopsies. Thirty-four of the 62 biopsied patients received endoscopic follow up.

RESULTS: Minute pharyngeal lesions were diagnosed in 93 of approximately 3000 patients receiving magnified NBI examinations at the clinic. Of the 93 patients with IPCL type IV lesions, 80 were men, and 13 were women. Fifty-six were drinkers, and 57 were smokers. Two had esophageal cancer. Twenty-one lesions were located on the posterior hypopharyngeal wall, and 72 lesions were located on the posterior oropharyngeal wall. All 93 lesions were flat and showed similar findings in the magnified and unmagnified NBI examinations. Although almost all of the IPCL type IV lesions showed faint redness when examined under white light, it was difficult to diagnose the lesions using only this technique because the contrast was weaker than that achieved in the NBI examinations. Of the 93 lesions, only 3 had diameters greater than 2.1 mm. Sixty-two lesions of approximately 1 mm were biopsied in the clinic, whereas 17 larger lesions were treated by ESD at the Hiroshima University Hospital. Of the 79 pharyngeal lesions that were biopsied or resected by ESD, 5 were histologically diagnosed as high-grade dysplasia, 39 were diagnosed as low-grade dysplasia, and 39 were determined to be non-dysplastic lesions. There were no cancerous lesions. Histologically, abnormal cell size variations and increased nuclear size were observed in all of the high-grade dysplasia lesions, while the incidence of these findings in the low-grade dysplasia lesions was low. Of the 62 biopsied lesions, 45 were microscopically measurable. The measured diameters ranged from 0.1 to 2.0 mm. The dysplasia ratios increased with the diameters. A follow-up endoscopic examination of the 34 biopsied patients found the rate of complete resection by biopsy to be 79%. The largest lesion in which complete resection was expected was a low-grade dysplasia of 1.9 mm in diameter.

CONCLUSION: Minute pharyngeal lesions suspected to be dysplasia that are identified by NBI magnifying endoscopy should be biopsied to determine the diagnosis and further treatment.

Laryngoscopy, stroboscopy and other tools for the evaluation of voice disorders

This article discusses and analyzes the diagnosis and management of voice disorders. Beginning with an insightful description of dysphonia as a sign and symptom rather than diagnosis, and an analysis of its unifying principles, the discussion continues with a review of evaluation, laryngoscopy, stroboscopy, and their respective advantages and disadvantages.

The Usefulness of Magnifying Endoscopy and Narrow-Band Imaging in Measuring the Depth of Invasion before Endoscopic Submucosal Dissection

With the widespread application of endoscopic submucosal dissection for the treatment of gastrointestinal neoplasms, accurate determination of the invasion depth prior to intervention has become an indispensable part of treatment planning. Narrow-band imaging (NBI) is a novel endoscopic technique that may enhance the accuracy of diagnosis. Magnifying endoscopy with NBI has been shown to be effective for determining invasion depth for intrapapillary capillary loop classification of esophageal cancer and microvascular pattern of stomach cancer. Such precise pre-treatment staging of early neoplastic lesions in the gastrointestinal tract warrants timely initiation of disease-tailored treatment and, ultimately, better quality of life and improved patient survival.

[A case of hypopharyngeal cancer treated by endoscopic submucosal dissection]

Recent advances in endoscopic instruments, including narrow-band imaging (NBI) and magnification endoscopy, allowed dramatic increase in the early diagnosis of hypopharyngeal cancers. In addition, endoscopic mucosal resection or endoscopic submucosal dissection has recently been used for the treatment of hypopharyngeal cancer at an early stage, especially in Japan. However, to date, there is no published report in Korea. A 68-year-old man was admitted for preoperative evaluation and treatment for known esophageal cancer initially diagnosed at a local clinic. During the evaluation, magnifying endoscopy combined with the NBI system revealed a concurrent hypopharyngeal cancer not detected by initial conventional endoscopy. In this case report, we describe for the first time in Korea a case of early stage hypopharyngeal carcinoma that was successfully treated by endoscopic submucosal dissection with a review of literature.

Magnifying endoscopy in upper gastroenterology for assessing lesions before completing endoscopic removal

Any prognosis of gastrointestinal (GI) cancer is closely related to the stage of the disease at diagnosis. Endoscopic submucosal dissection (ESD) and en bloc endoscopic mucosal resection (EMR) have been performed as curative treatments for many early-stage GI lesions in recent years. The technologies have been widely accepted in many Asian countries because they are minimally invasive and supply thorough histopathologic evaluation of the specimens. However, before engaging in endoscopic therapy, an accurate diagnosis is a precondition to effecting the complete cure of the underlying malignancy or carcinoma in situ. For the past few years, many new types of endoscopic techniques, including magnifying endoscopy with narrow-band imaging (ME-NBI), have emerged in many countries because these methods provide a strong indication of early lesions and are very useful in determining treatment options before ESD or EMR. However, to date, there is no comparable classification equivalent to "Kudo's Pit Pattern Classification in the colon", for the upper GI, there is still no clear internationally accepted classification system of magnifying endoscopy. Therefore, in order to help unify some viewpoints, here we will review the defining optical imaging characteristics and the current representative classifications of microvascular and microsurface patterns in the upper GI tract under ME-NBI, describe the accurate relationship between them and the pathological diagnosis, and their clinical applications prior to ESD or en bloc EMR. We will also discuss assessing the differentiation and depth of invasion, defying the lateral spread of involvement and targeting biopsy in real time.

NBI flexible laryngoscopy targeted tissue sampling in head and neck cancer patients with difficult airways

Direct suspension laryngoscopic biopsy of neoplasms in larynx, oropharynx, and hypopharynx was an arduous procedure in patients with a history of head and neck cancer and difficult airways. This preliminary study was aimed to report the efficacy and safety of a narrow band imaging-guided biopsy of this category by flexible laryngoscopy. This is a retrospective chart review study conducted in setting of tertiary referral centre. Nineteen consecutive head and neck cancer patients with difficulty in general anesthesia and rigid endoscopic approach due to trismus, craniofacial deformities, and/or limited neck extension after cancer therapy were referred for endoscopic biopsy of their suspicious lesions in larynx, hypopharynx, or parts of oropharynx. Following topical anesthesia, a flexible laryngoscope was introduced through the nose into the pharynx. Under narrow band imaging magnified view, the specified tumor foci were biopsied in an office-based setting. All of the lesions were reached and biopsied to obtain sufficient tissue samples. The procedure took <20 min in every case. Twelve of the 19 pathologic examinations disclosed the malignancies at the first biopsy, and another underwent a second biopsy to prove cancer recurrence. The other six patients with benign lesions received further follow-up for at least 6 months and showed no recurrence. There were no complications associated with the technique. This study introduced that flexible laryngoscopy with narrow band imaging has the advantages of nimbleness, precision, and minimal morbidity. This combined technique may be a safe and promising method for tissue sampling of suspicious recurrence in head and neck cancer patients with difficult airways.

Narrow band imaging of squamous cell carcinoma tumors using topically delivered anti-EGFR antibody conjugated gold nanorods

BACKGROUND

Nanoparticles have recently gained interest as exogenous contrast agents in a variety of biomedical applications related to cancer detection and treatment. The objective of this study was to determine the potential of topically administered antibody conjugated gold nanorods (GNRs) for imaging squamous cell carcinomas (SCCs) of the skin using near-infrared narrowband imaging (NBI). Near-infrared (NIR) NBI images narrow wavelength bands to enhance contrast from plasmonic particles in a wide field portable and noncontact device that is clinically compatible for real-time tumor imaging and tumor margin demarcation.

STUDY DESIGN

We conjugated GNRs to Cetuximab, a clinically approved humanized antibody that targets the epidermal growth factor receptor (EGFR), which is overexpressed on the surface of many tumor cells, especially SCCs. We excised subcutaneous xenografts of SCCs (A431) from Swiss nu/nu mice and divided the tumors into two groups: (1) the targeted group (Cetuximab conjugated GNRs) and (2) the control group (polyethylene glycol-conjugated GNRs). After topical application of particles and incubation for 30 minutes, the tumors were washed and imaged using NBI. In addition, we performed two-photon imaging to quantify the binding of EGFR targeted GNRs in tumors and their depth profile.

RESULTS

The NBI images showed a visual increase in contrast from tumors after topical administration of targeted GNR. Targeted GNR tumors showed increased contrast compared to tumors administered with the control GNR. There was a statistically significant increase in mean pixel intensity (∼2.5×) from targeted GNR tumors (n = 6). Two-photon microscopy images of targeted GNRs confirmed their binding affinity to the EGF receptors over expressed in the A431 tumors.

CONCLUSION

We have demonstrated that a topical application of gold nanorods targeted specifically to tumor growth factor receptors results in a significantly higher image contrast compared to nontargeted gold nanorods. These results demonstrate the feasibility of near-infrared NBI to image and demarcate tumor margins during surgical resection using topical administration of targeted GNR.

High technology imaging in digestive endoscopy

A thorough endoscopic visualization of the digestive mucosa is essential for reaching an accurate diagnosis and to treat the different lesions. Standard white light endoscopes permit a good mucosa examination but, nowadays, the introduction of powerful endoscopic instrumentations increased ability to analyze the finest details. By applying dyes and zoom-magnification endoscopy further architectural detail of the mucosa can be elucidated. New computed virtual chromoendoscopy have further enhanced optical capabilities for the evaluation of submucosal vascolar pattern. Recently, confocal endomicroscopy and endocytoscopy were proposed for the study of ultrastructural mucosa details. Because of the technological contents of powerful instrumentation, a good knowledge of implemented technologies is mandatory for the endoscopist, nowadays. Nevertheless, there is a big confusion about this topic. We will try to explain these technologies and to clarify this terminology.

Magnifying narrowband imaging is more accurate than conventional white-light imaging in diagnosis of gastric mucosal cancer

BACKGROUND & AIMS

It is difficult to accurately diagnose patients with depressed gastric mucosal cancer based on conventional white-light imaging (C-WLI) endoscopy. We compared the real-time diagnostic yield of C-WLI for small, depressed gastric mucosal cancers with that of magnifying narrow-band imaging (M-NBI).

METHODS

We performed a multicenter, prospective, randomized, controlled trial of patients with undiagnosed depressed lesions ≤10 mm in diameter identified by esophagogastroduodenoscopy. Patients were randomly assigned to groups that were analyzed by C-WLI (n = 176) or M-NBI (n = 177) immediately after detection; the C-WLI group received M-NBI after C-WLI. We compared the diagnostic accuracy, sensitivity, and specificity between C-WLI and M-NBI and assessed the diagnostic yield of M-NBI conducted in conjunction with C-WLI.

RESULTS

Overall, 40 gastric cancers (20 in each group) were identified. The median diagnostic values for M-NBI and C-WLI were as follows: accuracy, 90.4% and 64.8%; sensitivity, 60.0% and 40.0%; and specificity, 94.3% and 67.9%, respectively. The accuracy and specificity of M-NBI were greater than those of C-WLI (P < .001); the difference in sensitivity was not significant (P = .34). The combination of M-NBI with C-WLI significantly enhanced performance compared with C-WLI alone; accuracy increased from (median) 64.8% to 96.6% (P < .001), sensitivity increased from 40.0% to 95.0% (P < .001), and specificity increased from 67.9% to 96.8% (P < .001).

CONCLUSIONS

M-NBI, in conjunction with C-WLI, identifies small, depressed gastric mucosal cancers with 96.6% accuracy, 95.0% sensitivity, and 96.8% specificity. These values are better than for C-WLI or M-NBI alone.

Recent Advances in Image-enhanced Endoscopy

The desire to better recognized such malignancies, which may be difficult to distinguish from inflammation or trauma, has accelerated the development of endoscopy with new optical technologies. Narrow-band imaging is a novel endoscopic technique that may enhance the accuracy of diagnosis using narrow-bandwidth filters in a red-green-blue sequential illumination system. Autofluorescence imaging is based on the detection of natural tissue fluorescence emitted by endogenous molecules. I-scan technology using a digital filter that modifies normal images through software functions, is the newly developed image-enhanced endoscopic technology from PENTAX. Flexible spectral imaging color enhancement enhances the visualization of mucosal structure and microcirculation by the selection of spectral transmittance with a dedicated wavelength. Confocal laser endomicroscopy images were collected with an argon beam with a scanning depth of 0 (epithelium) to 250 µm (lamina propria) and analyzed using the reflected light.

Long-term outcome of transoral organ-preserving pharyngeal endoscopic resection for superficial pharyngeal cancer

BACKGROUND

Early detection of pharyngeal cancer has been difficult. We reported that narrow-band imaging (NBI) endoscopy can detect superficial pharyngeal cancer, and these lesions can be treated endoscopically.

OBJECTIVE

To assess the safety and long-term efficacy of transoral organ-preserving pharyngeal endoscopic resection (TOPER) for superficial pharyngeal cancer.

DESIGN AND SETTING

Retrospective 2-center cohort study.

PATIENTS

The study included 104 consecutive patients with superficial pharyngeal cancer.

INTERVENTION

TOPER with the patients under general anesthesia.

MAIN OUTCOME MEASUREMENTS

Safety of the procedure, long-term survival, clinical outcome.

RESULTS

A total of 148 consecutive lesions were resected in 104 patients. There was no severe adverse event. Temporary tracheostomy was required in 17 patients (16%) to prevent airway obstruction. The median fasting period and hospital stay after TOPER were 2 days (range 1-20 days) and 8 days (range 3-58 days), respectively. Ninety-six patients (92%) had no local recurrence or distant metastases. Local recurrence at the primary site developed in 6 patients, but all were resolved by repeat TOPER. With a median follow-up period of 43 months (range 3-96 months), the overall survival rate at 5 years was 71% (95% CI, 59-82). Cause-specific survival rate at 5 years was 97% (95% CI, 93-100). The cumulative development rate of multiple cancers in pharyngeal mucosal sites at 5 years was 22% (95% CI, 12-33). The pharynx was preserved in all patients, and they experienced no loss of function.

LIMITATION

Retrospective design.

CONCLUSIONS

Peroral endoscopic resection of superficial pharyngeal cancer is a feasible and effective treatment with curative intent.

Differences of image enhancement in image-enhanced endoscopy: narrow band imaging versus flexible spectral imaging color enhancement

BACKGROUND

Narrow band imaging (NBI) can emphasize images of the surface microvasculature of lesions, because the central wavelengths of the NBI filter are 415 and 540 nm and these wavelengths are well absorbed by hemoglobin. Flexible spectral imaging color enhancement (FICE) increases the contrast in depictions of mucosal lesions. However, quantitative evaluation of the image enhancement shown by NBI and FICE has not been reported. The aim of this study was to measure and compare the degrees of image enhancement in NBI and FICE.

METHODS

We compared the visibility of human blood diluted with distilled water between that shown by white-light imaging (WLI) and that shown by NBI or FICE. One milliliter of human blood was plated onto a 12-well transparent plastic plate to set up doubling dilutions, from 1/2 to 1/2(23). High-definition endoscopes were used for each imaging method. A total of 11 endoscopists independently evaluated the visibility of the diluted blood. The median dilution was defined as the limit of visibility in each image.

RESULTS

NBI enabled clearer visualization of the presence of blood compared with conventional WLI. NBI recognized blood contamination up to a 1/2(14) dilution, whereas conventional WLI recognized blood contamination up to a 1/2(11) dilution. In contrast, FICE did not improve the visualization of diluted blood and recognized blood contamination up to a 1/2(10) dilution.

CONCLUSIONS

NBI more effectively enhanced images of diluted blood compared to conventional WLI, while FICE did not improve the visualization of the diluted blood. These data suggest the usefulness of NBI for the early detection of gastrointestinal neoplasia, which is accompanied by abundant neovascularization.

Endoscopic findings under narrow band imaging colonoscopy in ulcerative colitis

Narrow band imaging (NBI) depicts distinct intramucosal vascular network and pit pattern without any use of dye technique. It is thus suggested that NBI can be used for the assessment of severity in inflammatory bowel diseases, especially in ulcerative colitis (UC). In the active UC, NBI colonoscopy depicts friability as a black area. In the inflamed granular mucosa, crypt openings and villous structure become evident through the procedure. In the inactive UC, there are two types of mucosal vascular pattern; one being composed of deep, green vessels and superficial, black vessels, and the other lacking in superficial vessels. With used of a magnifying instrument, the mildly active mucosa can be classified into the mucosa with obvious crypt openings and that with villous structure. Mucosal vascular pattern in the inactive mucosa is shown as a honeycomb-like structure or irregular, tortuous structure under magnifying NBI observation. Furthermore, such NBI findings show close correlations with histologic findings including crypt distortion, goblet cell depletion and basal plasmacytosis. Therefore, NBI colonoscopy might be of value for the precise assessment of histologic severity in mildly active and inactive UC.

Autofluorescence imaging and magnification endoscopy

It is well known that angiogenesis is critical in the transition from premalignant to malignant lesions. Consequently, early detection and diagnosis based on morphological changes to the microvessels are crucial. In the last few years, new imaging techniques which utilize the properties of light-tissue interaction have been developed to increase early diagnosis of gastrointestinal (GI) tract neoplasia. We analyzed several “red-flag” endoscopic techniques used to enhance visualization of the vascular pattern of preneoplastic and neoplastic lesions (e.g. trimodal imaging including autofluorescence imaging, magnifying endoscopy and narrow band imaging). These new endoscopic techniques provide better visualization of mucosal microsurface structure and microvascular architecture and may enhance the diagnosis and characterization of mucosal lesions in the GI tract. In the near future, it is expected that trimodal imaging endoscopy will be practiced as a standard endoscopy technique as it is quick, safe and accurate for making a precise diagnosis of gastrointestinal pathology, with an emphasis on the diagnosis of early GI tract cancers. Further large-scale randomized controlled trials comparing these modalities in different patient subpopulations are warranted before their endorsement in the routine practice of GI endoscopy.

Narrow-banding images and structures of microvessels of colonic lesions

BACKGROUND

Magnifying colonoscopy with NBI has been shown to be useful for the differential diagnosis of tumors. However, the relationship between findings on NBI magnification and the microvessel architecture of colorectal lesions remains to be clarified.

AIMS

The aim of this study was to clarify the correlation between NBI findings and the microvascular architecture of colorectal lesions according to the depth of microvessels from the mucosal surface.

METHODS

A total of 22 colorectal lesions (11 tubular adenomas and 11 hyperplasia) obtained from 22 patients were studied. These lesions were analyzed microscopically on tissue specimens immunostained with CD34. Three-dimensional images were reconstructed from serial sections of tubular adenomas, hyperplasia, and normal mucosa.

RESULTS

Three-dimensional reconstructed images of tubular adenoma and normal mucosa to a depth of less than 150 μm from the mucosal surface showed similar structures to images obtained by NBI magnification. Microvessel diameter was significantly larger in tubular adenoma than in normal mucosa (P = 0.002) and hyperplasia (P = 0.034), and microvessel area was significantly larger in tubular adenoma than in normal mucosa (P < 0.001) and hyperplasia (P < 0.001) only in the superficial mucosal layer (to a depth of less than 150 μm).

CONCLUSIONS

TA was characterized by thicker microvessels and higher volume of microvessels than NM and HP. Compared with white light, NBI can more accurately depict the characteristics of microvessels because it uses light with short wavelengths, thereby contributing to high diagnostic capability.

Increased microcirculation in subepithelial invasion of lung cancer

BACKGROUND AND OBJECTIVE

Mucosal irregularity and hypervascularity associated with primary lung cancer in large airways are observed by bronchoscopy. The aim of this study was to evaluate microcirculation at subepithelial invasion sites of lung cancer.

METHODS AND PATIENTS

Between July 2001 and June 2007, 12 patients who had subepithelial invasion sites of lung cancer in the large airways (aged 52 to 74 years, 12 males) were enrolled into this study. They were 6 patients with adenocarcinoma, 4 patients with squamous cell carcinoma, and 2 patients with small cell carcinoma. We compared 12 control subjects without endobronchial abnormality (aged 51 to 83 years, 9 males and 3 females). The patients underwent conventional bronchoscopy and subsequent high magnification bronchovideoscopy with the conventional imaging and the narrow band imaging (NBI). For evaluating microcirculation of subepithelial invasion, hemoglobin index was calculated.

RESULTS

In high magnification view, aberrant microvessels and/or irregular mucosal thickening were observed at subepithelial invasion sites of lung cancer. Irregularly enlarged microvessels were increased and formed an aberrant microvessel network on the surface of irregular mucosa. The diameter of aberrant microvessels was significantly increased compared to normal microvessels. By switching to NBI, the aberrant microvessels were more clearly visualized. The levels of hemoglobin index were significantly higher in subepithelial invasion sites of lung cancer compared to normal mucosa.

CONCLUSION

In subepithelial invasion of lung cancer, aberrant microvessels are thought to be characteristic and subepithelial microcirculation may be increased.

A wireless narrowband imaging chip for capsule endoscope

This paper presents a dual-mode capsule gastrointestinal endoscope device. An endoscope combined with a narrowband image (NBI), has been shown to be a superior diagnostic tool for early stage tissue neoplasms detection. Nevertheless, a wireless capsule endoscope with the narrowband imaging technology has not been presented in the market up to now. The narrowband image acquisition and power dissipation reduction are the main challenges of NBI capsule endoscope. In this paper, we present the first narrowband imaging capsule endoscope that can assist clinical doctors to effectively diagnose early gastrointestinal cancers, profited from our dedicated dual-mode complementary metal-oxide semiconductor (CMOS) sensor. The dedicated dual-mode CMOS sensor can offer white-light and narrowband images. Implementation results show that the proposed 512 × 512 CMOS sensor consumes only 2 mA at a 3-V power supply. The average current of the NBI capsule with an 8-Mb/s RF transmitter is nearly 7 ~ 8 mA that can continuously work for 6 ~ 8 h with two 1.5-V 80-mAh button batteries while the frame rate is 2 fps. Experimental results on backside mucosa of a human tongue and pig's small intestine showed that the wireless NBI capsule endoscope can significantly improve the image quality, compared with a commercial-of-the-shelf capsule endoscope for gastrointestinal tract diagnosis.

Prospective replacement of magnifying endoscopy by a newly developed endocytoscope, the 'GIF-Y0002'

Endocytoscopy has the potential to reduce the need for histologic examination of biopsy specimens in cases of esophageal squamous cell carcinoma. Up to now, two types of endocytoscope have been used: the probe type and the integrated type. In this study we examined the utility of a newly developed endocytoscope, the 'GIF-Y0002,' which has a single lens allowing consecutive magnification from the conventional endoscopy level up to ×380. Using the GIF-Y0002, we examined 24 examples of normal esophageal mucosa to clarify the appearance of the microvasculature of the normal squamous epithelium in vivo. We also examined 11 cases of esophageal cancer in the same way, employing methylene blue as a vital dye to stain the surface cells. In normal squamous epithelium, we clarified the relationship between the subepithelial capillary network, IPCLs and subepithelial venules. With methylene blue staining, we observed typical squamous cells (low nuclear density and low N/C ratio without nuclear abnormality). When cancerous lesions were observed using lower-power magnification, we were able to visualize their microvascular architecture to the same extent as when conventional magnifying endoscopy was used. Furthermore, at higher magnification, we were able to visualize the features of blood flow in both superficial and advanced cancer. Methylene blue staining revealed an increase of nuclear density in all cases of cancer. The pathologist agreed to omit biopsy histology in 81.8% (9/11) of cancer cases considering the nuclear density and nuclear abnormality. The GIF-Y0002 provides information on cell abnormality in addition to the features revealed by currently available magnifying endoscopy.