Effective detection of bronchial preinvasive lesions by a new autofluorescence imaging bronchovideoscope system

Role of I-scan technique in screening for lung cancer in smokers with positive sputum cytology

Background

Lung cancer has a very poor prognosis and high mortality. Positive sputum for malignant and/or atypical cells warrants the need for fibreoptic bronchoscopy. White light bronchoscopy (WLB) is usually unable to detect preinvasive lesions; therefore, autofluorescence bronchoscopy (AFB) was introduced as a gold standard for detecting such lesions. The aim of this work was to investigate the role of I-scan as a screening tool for cancer in smoker patients showing positive sputum cytology.

Results

New suspicious findings under I-scan occurred in 11 patients (36.7%). The overall sensitivity of WLB alone to diagnose malignancy is 23.3%, in contrast to an added sensitivity of 50% when I-scan was combined with white light (p value < 0.05). The specificity of I-scan could not be assessed in the absence of control cases (true negatives). No major complications or deaths occurred. Haemorrhage and bronchospasm were the commonest minor complications.

Conclusions

The addition of I-scan to the routine white light examination can increase the overall sensitivity of bronchoscopic screening in cases of sputum suspicious for malignancy if put in experienced hand. The suggested increase in procedure duration due to the combined use of I-scan and white light bronchoscopy is not associated with life-threatening complications.

Drastic healing process after pembrolizumab monotherapy in a case of advanced squamous cell carcinoma with severe bronchial stenosis observed over a two-year period using continuous bronchoscopy: A case report

Programmed cell death-1 immune checkpoint inhibitor (ICI) antibody has proven to be effective in advanced non-small cell lung cancer (NSCLC) patients positive for programmed cell death-1 ligand-1. However, there are currently no reports which evaluate drug efficacy by continuous bronchoscopic observation. A 75-year-old man with complete right atelectasis was diagnosed with squamous cell carcinoma (SCC) of the right lower lobe (tumor proportion score: TPS 90%, cT4N3M0, stage 3C). For first-line chemotherapy, carboplatin and nab-paclitaxel were effective for the primary lesion and the right lung atelectasis improved. However, due to repeated febrile neutropenia with pneumonia, treatment was modified to pembrolizumab monotherapy. Bronchoscopic rebiopsy prior to second-line treatment revealed high TPS, with a severe stenosis in the right main bronchus. After three courses of pembrolizumab, the right main bronchus opened completely, and no signs of malignancy were observed. Bronchoscopic narrow-band and autofluorescence imaging also confirmed a complete endobronchial response. Subsequent bronchoscopic observation two years after the initial diagnosis showed a complete and continued response to treatment. ICIs can result in a drastic bronchoscopic response. In this case, the healing process was notable with minimal scarring, and resulted in continued locally bronchoscopic and complete pathological response to treatment compared to previous cytotoxic chemotherapy.

Comparison of autofluorescence and white-light bronchoscopies performed with the Evis Lucera Spectrum for the detection of bronchial cancers: a meta-analysis

Background

Many recent studies have reported that autofluorescence bronchoscopy (AFB) has a superior sensitivity and decreased specificity in the diagnosis of bronchial cancers when compared with white-light bronchoscopy (WLB). We specifically analyzed the diagnostic performances of autofluorescence imaging video bronchoscopy (AFI) performed with the Evis Lucera Spectrum from Olympus, which is a relatively novel approach in detecting and delineating bronchial cancers, and compared it to the older WLB method.

Methods

We searched the PubMed, Embase, Web of Science, and CNKI databases from inception to July 12^th, 2018 for trials in which patients were diagnosed with lung cancer via concurrent or combined use of AFI and WLB. The included studies were required to have a histologic diagnosis as the gold standard comparison, and a sufficient amount of data was extracted to assess the diagnostic capacity. A 2×2 table was constructed, and the area under the receiver-operating characteristic curve (AUC) of AFI and WLB was estimated by using a stochastic model for diagnostic meta-analysis using STATA software.

Results

A total of 10 articles were eligible for the meta analysis, comprising 1,830 patients with complete data included in the analysis. AFI showed a superior sensitivity of 0.92 (95% CI, 0.88-0.95) over WLB's 0.70 (95% CI, 0.58-0.80) with P<0.01, and a comparable specificity of 0.67 (95% CI, 0.51-0.80) compared with WLB's 0.78 (95% CI, 0.68-0.86) with P=0.056. Egger's test P value (0.225) demonstrated that there was no publication bias.

Conclusions

Our research showed that in the evaluation of bronchial cancers, AFI was superior to conventional WLB. With its higher sensitivity, AFI could be valuable for avoiding misdiagnosis.

Feasibility of lung cancer screening in developing countries: challenges, opportunities and way forward

Lung cancer is the leading cause of all cancer deaths worldwide, comprising 18.4% of all cancer deaths. Low-dose computed tomography (LDCT) has shown mortality benefit in various trials and now a standard tool for lung cancer screening. Most researches have been carried out in developed countries where lung cancer incidence and mortality is very high. There is an increasing trend in lung cancer incidence in developing countries attributed to tobacco smoking and various environmental and occupational risk factors. Implementation of lung cancer screening is challenging, so organised lung cancer screening is practically non-existent. There are numerous challenges in implementing such programs ranging from infrastructure, trained human resources, referral algorithm to cost and psychological trauma due to over-diagnosis. Pulmonary tuberculosis and other chest infections are important issues to be addressed while planning for lung cancer screening in developing countries. Burden of these diseases is very high and can lead to over-diagnosis in view of cut off of lung nodule size in various studies. Assessment of high risk cases for lung cancer is difficult as various forms of smoking make quantification non-uniform and difficult. Lung cancer screening targets only high risk population unlike screening programs for other cancers where entire population is targeted. There is a need of lung cancer screening for high risk cases as it saves life. Tobacco control and smoking cessation remain the most important long term intervention to decrease morbidity and mortality from lung cancer in developing countries. There is no sufficient evidence supporting the introduction of population-based screening for lung cancer in public health services.

[Modern approaches to the diagnosis of precancerous pathology and early lung cancer]

AIM

To assess the possibilities of modern diagnostic techniques to diagnose precancerous pathology and early central lung cancer.

MATERIAL AND METHODS

Analysis of Russian and foreign publications for precancerous pathology and early lung cancer, results and comparison of various diagnostic techniques.

RESULTS

Central lung cancer has a stepwise development with transformation of normal bronchial epithelium to hyperplastic followed by focal metaplasia, dysplasia, cancer in situ (CIS) and microinvasive cancer. Fluorography, chest X-ray, computed tomography, magnetic resonance imaging and sputum cytology examination are used to diagnose lung cancer. However, endoscopy plays a leading role in diagnosis of early central lung cancer which rapidly and effectively detects changes of tracheobronchial tree mucosa at the initial stages of carcinogenesis thanks to the use of modern techniques (spectral, autofluorescent and ZOOM - endoscopy).

Bronchoscopy: Diagnostic and Therapeutic for Non-Small Cell Lung Cancer

The bronchoscope has gone through much advancement from its origin as a thin metal tube. It has become a highly sophisticated tool for clinicians. Both rigid and the flexible bronchoscopes are invaluable in the diagnosis and treatment of non-small cell lung cancer. Treatment of this disease process hinges on accurate diagnosis and lymph node staging. Technologies, such as endobronchial ultrasound, navigational bronchoscopy, and autofluorescence, have improved efficacy of endobronchial diagnosis and sample collection. If a patient is not a candidate for surgery and has a complication from a centrally located mass, the bronchoscope has been used to deliver palliative therapies.

The technique of endoscopic airway tumor treatment

More than half of primary lung cancers are not resectable at diagnosis and 40% of deaths may be secondary to loco-regional disease. Many of these patients suffer from symptoms related to airways obstruction. Indications for therapeutic endoscopic treatment are palliation of dyspnea and other obstructive symptoms in advanced cancerous lesions and cure of early lung cancer. Bronchoscopic management is also indicated for all those patients suffering from benign or minimally invasive neoplasm who are not suitable for surgery due to their clinical conditions. Clinicians should select cases, evaluating tumor features (size, location) and patient characteristics (age, lung function impairment) to choose the most appropriate endoscopic technique. Laser therapy, electrocautery, cryotherapy and stenting are well-described techniques for the palliation of symptoms due to airway involvement and local treatment of endobronchial lesions. Newer technologies, with an established role in clinical practice, are endobronchial ultrasound (EBUS), autofluorescence bronchoscopy (AFB), and narrow band imaging (NBI). Other techniques, such as endobronchial intra-tumoral chemotherapy (EITC), EBUS-guided-transbronchial needle injection or bronchoscopy-guided radiofrequency ablation (RFA), are in development for the use within the airways. These endobronchial interventions are important adjuncts in the multimodality management of lung cancer and should become standard considerations in the management of patients with advanced lung cancer, benign or otherwise not approachable central airway lesions. We aimed at revising several endobronchial treatment modalities that can augment standard antitumor therapies for advanced lung cancer, including rigid and flexible bronchoscopy, laser therapy, endobronchial prosthesis, and photodynamic therapy (PDT).

The role of bronchoscopy in the diagnosis of early lung cancer: a review

Lung cancer is the leading cause of cancer-related deaths worldwide with an overall 5-year survival rate of 17% after diagnoses. Indeed many patients tend to have a very poor prognosis, due to being diagnosed at an advanced stage. Conversely patients who are diagnosed at an early stage have a 5-year survival >70%, indicating that early detection of lung cancer is crucial to improve survival. Although flexible bronchoscopy is a relatively non-invasive procedure for patients suspected of having lung cancer, only 29% of carcinoma in situ (CIS) and 69% of microinvasive tumors were detectable using white light bronchoscopy (WLB) alone. As a result, in the past two decades, new bronchoscopic techniques have been developed to increase the yield and diagnostic accuracy, such as autofluorescence bronchoscopy (AFB), narrow band imaging (NBI) and high magnification bronchovideoscopy (HMB). However, due to the low specificity and the limitation to detect only proximal bronchial tree, new probe-based technologies have been introduced: radial endobronchial ultrasound (R-EBUS), optical coherence tomography (OCT), confocal laser endomicroscopy (CLE) and laser Raman spectroscopy (LRS). To date, although tissue biopsy remains the gold standard for diagnosing malignant/premalignant airway disease and some techniques are still investigational, bronchoscopic technologies can be considered the safest and most accurate tools to evaluate both central and distal airway mucosa.

White light, autofluorescence and narrow-band imaging bronchoscopy for diagnosing airway pre-cancerous and early cancer lesions: a systematic review and meta-analysis

BACKGROUND

We aimed to summarize the diagnostic accuracy of white light bronchoscopy (WLB) and advanced techniques for airway pre-cancerous lesions and early cancer, such as autofluorescence bronchoscopy (AFB), AFB combined with WLB (AFB + WLB) and narrow-band imaging (NBI) bronchoscopy.

METHODS

We searched for eligible studies in seven electronic databases from their date of inception to Mar 20, 2015. In eligible studies, detected lesions should be confirmed by histopathology. We extracted and calculated the 2×2 data based on the pathological criteria of lung tumor, including high-grade lesions from moderate dysplasia (MOD) to invasive carcinoma (INV). Random-effect model was used to pool sensitivity, specificity, diagnostic odds ratio (DOR) and the area under the receiver-operating characteristic curve (AUC).

RESULTS

In 53 eligible studies (39 WLB, 39 AFB, 17 AFB + WLB, 6 NBI), diagnostic performance for high-grade lesions was analyzed based on twelve studies (10 WLB, 7 AFB, 7 AFB + WLB, 1 NBI), involving with totally 2,880 patients and 8,830 biopsy specimens. The sensitivity, specificity, DOR and AUC of WLB were 51% (95% CI, 34-68%), 86% (95% CI, 73-84%), 6 (95% CI, 3-13) and 77% (95% CI, 73-81%). Those of AFB and AFB + WLB were 93% (95% CI, 77-98%) and 86% (95% CI, 75-97%), 52% (95% CI, 37-67%) and 71% (95% CI, 56-87%), 15 (95% CI, 4-57) and 16 (95% CI, 6-41), and 76% (95% CI, 72-79%) and 82% (95% CI, 78-85%), respectively. NBI presented 100% sensitivity and 43% specificity.

CONCLUSIONS

With higher sensitivity, advanced bronchoscopy could be valuable to avoid missed diagnosis. Combining strategy of AFB and WLB may contribute preferable diagnosis rather than their alone use for high-grade lesions. Studies of NBI warrants further investigation for precancerous lesions.

Accuracy of autofluorescence in diagnosing oral squamous cell carcinoma and oral potentially malignant disorders: a comparative study with aero-digestive lesions

Presently, various studies had investigated the accuracy of autofluorescence in diagnosing oral squamous cell carcinoma (OSCC) and oral potentially malignant disorders (OPMD) with diverse conclusions. This study aimed to assess its accuracy for OSCC and OPMD and to investigate its applicability in general dental practice. After a comprehensive literature search, a meta-analysis was conducted to calculate the pooled diagnostic indexes of autofluorescence for premalignant lesions (PML) and malignant lesions (ML) of the oral cavity, lung, esophagus, stomach and colorectum and to compute indexes regarding the detection of OSCC aided by algorithms. Besides, a u test was performed. Twenty-four studies detecting OSCC and OPMD in 2761 lesions were included. This demonstrated that the overall accuracy of autofluorescence for OSCC and OPMD was superior to PML and ML of the lung, esophagus and stomach, slightly inferior to the colorectum. Additionally, the sensitivity and specificity for OSCC and OPMD were 0.89 and 0.8, respectively. Furthermore, the specificity could be remarkably improved by additional algorithms. With relatively high accuracy, autofluorescence could be potentially applied as an adjunct for early diagnosis of OSCC and OPMD. Moreover, approaches such as algorithms could enhance its specificity to ensure its efficacy in primary care.

Lung cancer screening: history, current perspectives, and future directions

Lung cancer has remained the leading cause of death worldwide among all cancers. The dismal 5-year survival rate of 16% is in part due to the lack of symptoms during early stages and lack of an effective screening test until recently. Chest X-ray and sputum cytology were studied extensively as potential screening tests for lung cancer and were conclusively proven to be of no value. Subsequently, a number of studies compared computed tomography (CT) with the chest X-ray. These studies did identify lung cancer in earlier stages. However, they were not designed to prove a reduction in mortality. Later trials have focused on low-dose CT (LDCT) as a screening tool. The largest US trial - the National Lung Screening Trial (NLST) - enrolled approximately 54,000 patients and revealed a 20% reduction in mortality. While a role for LDCT in lung cancer screening has been established, the issues of high false positive rates, radiation risk, and cost effectiveness still need to be addressed. The guidelines of the international organizations that now include LDCT in lung cancer screening are reviewed. Other methods that may improve earlier detection such as positron emission tomography, autofluorescence bronchoscopy, and molecular biomarkers are also discussed.

A pilot study of autofluorescence in the diagnosis of pleural disease

BACKGROUND

Conventional medical thoracoscopy (MT), routinely performed in patients with pleural disease, does not always lead to a conclusive diagnosis. The endoscopic appearance of pleural diseases under white light could be misleading. Autofluorescence has been shown to be an interesting and effective diagnostic tool. The objective of this study was to evaluate the diagnostic value of autofluorescence imaging during MT.

METHODS

Patients with undiagnosed pleural effusion admitted to our clinical center between August 2013 and February 2014 were enrolled. MT was performed first with white light and then by autofluorescence. Endoscopic results of different diseases were recorded, and biopsy specimens were obtained for pathologic analysis. We calculated the diagnostic sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the two methods by comparing them with the pathologic results.

RESULTS

Thirty-seven eligible patients were studied, including 21 with malignancy, nine with tuberculous pleurisy, three with infective pleurisy, and four with no diagnosed condition. Autofluorescence revealed additional malignant lesions, which were missed under white light in five patients. The diagnostic sensitivity and NPV of autofluorescence were 100% (95% CI, 98.5%-100%) and 100% (95% CI, 93.9%-100%), respectively. Autofluorescence was superior to white light, with a sensitivity of 92.8% (95% CI, 89.3%-95.3%) and NPV of 76.8% (95% CI, 67.0%-84.4%). For the specificity and PPV, no significant difference was found.

CONCLUSIONS

The advantage of autofluorescence is its high sensitivity and NPV. It is useful to detect microlesions and delineate the pathologic margins. Autofluorescence can benefit patients with its better visualization.

Photodynamic diagnoses of malignant pleural diseases using the autofluorescence imaging system

BACKGROUND

We conducted a study on photodynamic diagnosis (PDD) using autofluorescence in video-assisted thoracic surgery for minute intrathoracic small dissemination or early malignant pleural mesothelioma.

METHODS

Autofluorescence is the spontaneous emission of light that occurs when mitochondria, lysosomes, and other intracellular organelles absorb light. In normal tissues, green autofluorescence of approximately 520 nm is observed in response to 400-450 nm blue excitation rays. However, in cancer lesions, green autofluorescence is reduced due to thickening of the mucosal epithelium, a decrease in autofluorescent substances, etc., and the color spectrum thus shifts to red-violet. This phenomenon is the basis of PDD.

RESULTS

The color spectrum shift was observed in all tumors located on the pleural surface but not in cases with pleural fibrous disease. Among patients with primary lung cancer, those with pleural infiltration (pl) scores of 1 or greater showed color spectrum shifts due to reduced autofluorescence.

CONCLUSION

Localization of pleural lesions by autofluorescence imaging was found to be useful. In primary lung cancer cases, differentiation between pl0 and pl1 lesions appears to be useful for determining therapeutic strategies including surgical procedures.

Advanced bronchoscopic techniques in diagnosis and staging of lung cancer

The role of advanced brochoscopic diagnostic techniques in detection and staging of lung cancer has steeply increased in recent years. Bronchoscopic imaging techniques became widely available and easy to use. Technical improvement led to merging in technologies making autofluorescence or narrow band imaging incorporated into one bronchoscope. New tools, such as autofluorescence imagining (AFI), narrow band imaging (NBI) or fuji intelligent chromo endoscopy (FICE), found their place in respiratory endoscopy suites. Development of endobronchial ultrasound (EBUS) improved minimally invasive mediastinal staging and diagnosis of peripheral lung lesions. Linear EBUS proven to be complementary to mediastinoscopy. This technique is now available in almost all high volume centers performing bronchoscopy. Radial EBUS with mini-probes and guiding sheaths provides accurate diagnosis of peripheral pulmonary lesions. Combining EBUS guided procedures with rapid on site cytology (ROSE) increases diagnostic yield even more. Electromagnetic navigation technology (EMN) is also widely used for diagnosis of peripheral lesions. Future development will certainly lead to new improvements in technology and creation of new sophisticated tools for research in respiratory endoscopy. Broncho-microscopy, alveoloscopy, optical coherence tomography are some of the new research techniques emerging for rapid technological development.

Transformed lymphoplasmacytic lymphoma involving the main carina: A case report

A 41-year-old male was admitted to Nagoya City University Hospital subsequent to experiencing a cough with bloody sputum for a few days. The patient had a 4-year history of lymphoplasmacytic lymphoma (LPL) and had achieved a good partial response to anticancer chemotherapy. Chest computed tomography (CT) showed an endobronchial tumor of the main carina. A bronchoscopy revealed an exophytic tumor at the main carina, and autofluorescence imaging bronchovideoscopy showed that the tumor and surrounding area were magenta in color. The biopsy specimens demonstrated that the endobronchial tumor was composed of large atypical lymphoid cells. The patient was diagnosed with a high-grade transformation of LPL. In addition to describing a rare case of transformed LPL involving the main carina, the present study also summarizes and discusses endobronchial lymphomas, with a brief review of a number of published studies.

Diagnosis and treatment of bronchial intraepithelial neoplasia and early lung cancer of the central airways: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

Bronchial intraepithelial lesions may be precursors of central airway lung carcinomas. Identification and early treatment of these preinvasive lesions might prevent progression to invasive carcinoma.

METHODS

We systematically reviewed the literature to develop evidence-based recommendations regarding the diagnosis and treatment of intraepithelial lesions.

RESULTS

The risk and timeline for progression of bronchial intraepithelial lesions to carcinoma in situ (CIS) or invasive carcinoma are not well understood. Multiple studies show that autofluorescence bronchoscopy (AFB) is more sensitive that white light bronchoscopy (WLB) to identify these lesions. In patients with severe dysplasia or CIS in sputum cytology who have chest imaging studies showing no localizing abnormality, we suggest use of WLB; AFB may be used as an adjunct when available. Patients with known severe dysplasia or CIS of central airways should be followed with WLB or AFB, when available. WLB or AFB is also suggested for patients with early lung cancer who will undergo resection for delineation of tumor margins and assessment of synchronous lesions. However, AFB is not recommended prior to endobronchial therapy for CIS or early central lung cancer. Several endobronchial techniques are recommended for the treatment of patients with superficial limited mucosal lung cancer who are not candidates for resection.

CONCLUSION

Additional information is needed about the natural history and rate of progression of preinvasive central airway lesions. Patients with severe dysplasia or CIS may be treated endobronchially; however, it remains unclear if these therapies are associated with improved patient outcomes.

Detection and minimally invasive treatment of early squamous lung cancer

Non-small cell lung cancer (NSCLC) is the most common cause of cancer deaths worldwide. The majority of patents presenting with NSCLC have advanced disease, which precludes curative treatment. Early detection and treatment might result in the identification of more patients with early central lung cancer and improve survival. In addition, the study of early lung cancer improves understanding of lung carcinogenesis and might also reveal new treatment targets for advanced lung cancer. Bronchoscopic investigation of the central airways can reveal both early central lung cancer in situ (stage 0) and other preinvasive lesions such as dysplasia. In the current review we discuss the detection of early squamous lung cancer, the natural history of preinvasive lesions and whether biomarkers can be used to predict progression to cancer. Finally we will review the staging and management of preinvasive lung cancer lesions and the different therapeutic modalities that are available.

Early lung cancer: methods for detection

Early detection and surgical resection are essential for the treatment of lung cancer. It would be ideal to be able to detect and treat preinvasive bronchial lesions, defined as dysplasia and carcinoma in situ before progressing to invasive cancer. Advanced airway-assessment techniques have opened an avenue for early detection and surveillance of endobronchial malignancy. This article reviews currently available advanced imaging techniques for early detection of lung cancer, including autofluorescence bronchoscopy, narrow-band imaging, high-magnification bronchovideoscopy, endobronchial ultrasonography, and optical coherence tomography. Also discussed are the more recently developed endocytoscopy system and confocal fluorescence microendoscopy, currently used only for research purposes.

Detection of premalignant bronchial lesions can be significantly improved by combination of advanced bronchoscopic imaging techniques

BACKGROUND:

The search for the most efficient bronchoscopic imaging tool in detection of early lung cancer is still active. The major aim of this study was to determine sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of each bronchoscopic technique and their combination in detection of premalignant bronchial lesions.

METHODS:

This was a prospective trial that enrolled 96 patients with indication for bronchoscopy. Lesions were classified as visually positive if pathological fluorescence was observed under autofluorescence imaging (AFI) videobronchoscopy or dotted, tortuous, and abrupt-ending blood vessels were identified under narrow band imaging (NBI) videobronchoscopy. Squamous metaplasia, mild, moderate, or severe dysplasia, and carcinoma in situ (CIS) were regarded as histologically positive lesions.

RESULTS:

Sensitivity, specificity, PPV, and NPV of white light videobronchoscopy (WLB) in detection of premalignant lesions were 26.5%, 63.9%, 34.4%, and 54.9%, respectively; the corresponding values for AFI were 52%, 79.6%, 64.6%, and 69.9% respectively, for NBI were 66%, 84.6%, 75.4%, 77.7%, respectively, while the values for combination of NBI and AFI were 86.1%, 86.6%, 84.6%, and 88%, respectively. Combination of NBI and AFI significantly improves sensitivity when compared to each individual technique (P < 0.001). When specificity is of concern, combination of techniques improves specificity of WLB (P < 0.001) and specificity of AFI (P = 0.03), but it does not have significant influence on specificity of NBI (P = 0.53).

CONCLUSION:

Combination of NBI and AFI in detection of premalignant bronchial lesions increases both sensitivity and specificity of each technique. However, it seems that NBI is most sufficient and effective in detection of these lesions.

Diagnostic value of autofluorescence bronchoscopy in lung cancer

The role of autofluorescence bronchoscopy (AFB) was primarily investigated in regard to the detection of precancerous lesions of bronchial mucosa. Most of the results confirmed higher sensitivity for the detection of precancerous bronchial lesions, when compared to white light bronchoscopy (WLB) alone. However, it is commonly known that the specificity of AFB remains low. Our findings agree in terms of the detection of premalignant bronchial lesions and early lung cancer, but regarding the detection of synchronous lesions or in the evaluation of lung cancer extension, the specificity of AFB is significantly higher. There is still an ongoing debate in the scientific community whether or not autofluorescence should be used as a screening tool for lung cancer. Results of the majority of published series did not support the general use of AFB as a screening tool for lung cancer; however, these results suggest its use in groups of patients with a high risk of lung cancer. Despite this, some authors still do not recommend its use even in high-risk cases. In recent years, the indications for AFB have been widening and this tool may find its place in routine bronchoscopy. With new indications for AFB, such as the evaluation of tumor extension or follow up after surgical resection, bronchoscopists may make use of this tool more often. A sharp learning curve and a clear distinction between healthy and pathologically altered mucosa make this technology acceptable for inexperienced bronchoscopists. We also investigate new hardware and software improvements in AFB. The addition of backscattered light analysis, ultraviolet spectra, fluorescence-reflectance or dual digital systems could improve the diagnostic yield of this technology.

Comparison of autofluorescence imaging bronchoscopy and white light bronchoscopy for detection of lung cancers and precancerous lesions

BACKGROUND

The purpose of this paper was to compare the sensitivity, specificity, and overall diagnostic performance of autofluorescence imaging bronchoscopy (AFI) versus white light bronchoscopy (WLB) in the detection of lung cancers and precancerous lesions by meta-analysis.

METHODS

We performed a literature search using the PubMed and EMBASE databases to identify studies published between March 1991 and March 2012. Article selection, quality assessment, and data extraction were then performed. The pooled sensitivity, specificity, diagnostic odds ratio, and area under the curve of the summary receiver operating characteristic for AFI versus WLB were calculated using Stata version 12.0 software.

RESULTS

Six studies were included in the meta-analysis. The pooled sensitivity of AFI and WLB was 0.89 (95% confidence interval [CI] 0.81-0.94) and 0.67 (95% CI 0.46-0.83) and the pooled specificity of AFI and WLB was 0.64 (95% CI 0.37-0.84) and 0.84 (95% CI 0.74-0.91), respectively. The diagnostic odds ratio for AFI and WLB was 14.5 (95% CI 3.76-55.63) and 10.9 (95% CI 3.12-38.21), and the area under the curve for AFI and WLB was 0.89 (95% CI 0.86-0.92) and 0.85 (95% CI 0.81-0.88), respectively. The pooled positive and negative likelihood ratios were 2.5 (95% CI 1.21-4.97) and 0.17 (95% CI 0.08-0.36) for AFI, and the corresponding values for WLB were 4.3 (95% CI 2.13-8.52) and 0.39 (95% CI 0.21-0.73). The pooled positive likelihood ratio for AFI and WLB was not higher than 10, and the pooled negative likelihood ratio for AFI and WLB was not lower than 0.1.

CONCLUSION

The sensitivity of AFI is higher than that of WLB, while the specificity of AFI is lower than that of WLB. The overall diagnostic performance of AFI is slightly better than that of WLB in detecting lung cancers and precancerous lesions. AFI should find its place in routine bronchoscopic examination and may improve the diagnostic outcome on endoscopy.

New aspects of photodynamic therapy for central type early stage lung cancer

BACKGROUND

and Objective Photodynamic therapy (PDT) has come to be considered as the first choice of treatment for central type early stage lung cancer (CELC). Recent advances in the ability to diagnose CELC, and in photosensitizers, as well as sophisticated clinical management, may improve the therapeutic outcome and expand the indications of PDT.

MATERIALS AND METHODS

We made the search for papers on PDT for lung cancer to select the most relevant articles. Based on this review and our recent data, we discussed the best available evidence for the diagnosis, the definition of indications, photosensitizers, and clinical management with regard to PDT.

RESULTS

To obtain complete response (CR) by PDT, the selection of the indications is extremely important, including the extent of the tumor on the bronchial surface and the depth of invasion in the bronchial wall. The development of autofluorescence bronchoscopy (AFB) and endobronchial ultrasonography (EBUS) have had a large impact on diagnostic bronchoscopy for CELC. CELCs less than 1 cm in diameter showed a favorable cure rate by PDT, thus this is a good indication for PDT. The relatively newer photosensitizer NPe6, which has a stronger antitumor effect than Photofrin, showed similar treatment outcome even for large tumors >1.0 cm in diameter. Furthermore, comprehensive management including photodynamic diagnosis before and after PDT should be effective to minimize the possibility of local recurrence after PDT.

CONCLUSION

The present guidelines of PDT for CELC were established based on the data obtained from studies in the 1980's. We postulate that comprehensive diagnosis and the new generation of photosensitizers may increase the CR rate and expand the indications of PDT for larger tumors.

Frontiers in bronchoscopic imaging

Bronchoscopy is a minimally invasive method for diagnosis of diseases of the airways and the lung parenchyma. Standard bronchoscopy uses the reflectance/scattering properties of white light from tissue to examine the macroscopic appearance of airways. It does not exploit the full spectrum of the optical properties of bronchial tissues. Advances in optical imaging such as optical coherence tomography (OCT), confocal endomicroscopy, autofluorescence imaging and laser Raman spectroscopy are at the forefront to allow in vivo high-resolution probing of the microscopic structure, biochemical compositions and even molecular alterations in disease states. OCT can visualize cellular and extracellular structures at and below the tissue surface with near histological resolution, as well as to provide three-dimensional imaging of the airways. Cellular and subcellular imaging can be achieved using confocal endomicroscopy or endocytoscopy. Contrast associated with light absorption by haemoglobin can be used to highlight changes in microvascular structures in the subepithelium using narrow-band imaging. Blood vessels in the peribronchial space can be displayed using Doppler OCT. Biochemical compositions can be analysed with laser Raman spectroscopy, autofluorescence or multispectral imaging. Clinically, autofluorescence and narrow-band imaging have been found to be useful for localization of preneoplastic and neoplastic bronchial lesions. OCT can differentiate carcinoma in situ versus microinvasive cancer. Endoscopic optical imaging is a promising technology that can expand the horizon for studying the pathogenesis and progression of airway diseases such as COPD and asthma, as well as to evaluate the effect of novel therapy.

Optical detection of preneoplastic lesions of the central airways

Current routine diagnosis of premalignant lesions of the central airways is hampered due to a limited sensitivity (white light bronchoscopy) and resolution (computer tomography (CT), positron emission tomography (PET)) of currently used techniques. To improve the detection of these subtle mucosal abnormalities, novel optical imaging bronchoscopic techniques have been developed over the past decade. In this review we highlight the technological developments in the field of endoscopic imaging, and describe their advantages and disadvantages in clinical use.

Update on interventional bronchoscopy for the thoracic radiologist

Interventional bronchoscopy, together with other domains of interventional pulmonology, has experienced tremendous technological advances. Diagnostic applications include endobronchial ultrasound, which enables endoscopists to see through airway walls. White light videobronchoscopy, autofluorescence imaging, and narrow band imaging have enhanced the ability to detect early lung cancer at a preinvasive stage. Electromagnetic navigational bronchoscopy, ultrathin bronchoscopy, and virtual bronchoscopy increase the diagnostic yield of biopsy of small peripheral lung lesions. The options that are currently available for the relief of central airway obstruction are also numerous, with both flexible and rigid bronchoscopic applications. Stents, although dichotomized to silicone and metal, come in various sizes and shapes to suit the requirements of the pathology being treated. Ablative techniques are categorized into those with an immediate effect and those with a delayed effect. Laser, electrocautery, and argon plasma coagulation can immediately relieve obstruction and control hemoptysis, whereas cryosurgery, brachytherapy, and photodynamic therapy have established roles in subacute airway obstruction and in the treatment of early lung cancer. Microdebriders have recently been added to the armamentarium of modalities for mechanical debulking of tumor. Distal airway obstruction has also been targeted with bronchial thermoplasty treatment of refractory asthma and with bronchoscopic lung volume reduction for the management of severe emphysema. This array of new technology has fostered collaborative work with a wide range of other medical specialties to deliver safer, more effective, minimally invasive treatment.

Dual-wavelength excitation of mucosal autofluorescence for precise detection of diminutive colonic adenomas

BACKGROUND

The mucosal layer of the colon contains metabolism-related fluorophores, such as reduced nicotinamide adenine dinucleotide (NADH), which might have the potential to serve as biomarkers for detecting neoplasia.

OBJECTIVE

To examine NADH fluorescence in human colonic adenoma while eliminating the effect of hemoglobin absorption and to develop a novel imaging technique for precise detection of adenomas.

DESIGN

Cross-sectional study.

PATIENTS AND INTERVENTIONS

A total of 66 endoscopically resected colonic polyps were investigated. After serial acquisition of autofluorescence images between 450 and 490 nm illuminated with dual-wavelength excitation at 365 nm (F(365ex)) and 405 nm (F(405ex)) on cross sections of the samples, ratio images were created by dividing F(365ex) by F(405ex). The excitation-emission wavelength combinations in F(365ex) and F(405ex) were optimized for NADH fluorescence and reference fluorescence.

MAIN OUTCOME MEASUREMENTS

The F(365ex)/F(405ex) ratio in the tumorous (T) and normal (N) mucosa.

RESULTS

F(365ex)/F(405ex) ratio images showed a 1.81- and 1.12-fold higher signal intensity in the adenomas and hyperplastic polyps, respectively, than in the adjacent normal mucosa. The ratio between signal intensities in tumorous mucosa and normal mucosa in F(365ex)/F(405ex) ratio images for tubular adenomas was significantly higher than that for hyperplastic polyps. The signal intensity in F(365ex)/F(405ex) ratio images was not correlated with the hemoglobin concentration index evaluated by reflection images at 550 nm and 610 nm. Diminutive adenomas (<5 mm) and large adenomas were well discriminated in F(365ex)/F(405ex) ratio images.

LIMITATIONS

Ex vivo experiment.

CONCLUSIONS

These results suggest that the precise measurement of NADH fluorescence intensity together with eliminating the influence of blood hemoglobin concentration serves as a method for visualizing colonic adenomas and that the dual-wavelength excitation method is a promising technique applicable to endoscopic detection of early colonic adenomas.

Autofluorescence imaging videobronchoscopy in the detection of lung cancer: from research tool to everyday procedure

Autofluorescence imaging videobronchoscopy (AFI) is one of the new systems of autofluorescence bronchoscopy designed for thorough examination of bronchial mucosa. The integration of autofluorescence and videobronchoscopy provides clear images of normal and pathologically altered bronchial mucosa. Major indications for AFI include evaluation of early-stage lung cancer and detection of precancerous lesions. However, in recent years, the indications for AFI are widening, and this tool might find its place in routine daily bronchoscopic practice. With new indications for AFI, such as evaluation of tumor extension or follow-up after surgical resection, this tool might be more often used by bronchoscopists. A sharp learning curve and clear distinction between healthy and pathologically altered mucosa make this technology acceptable for young and inexperienced bronchoscopists. One of the major disadvantages of AFI is low specificity in the detection of premalignant lesions and early-stage lung cancer. This disadvantage could be overcome with the appearance of new and improved technologies in autofluorescence, such as the addition of backscattered light analysis, ultraviolet spectra, fluorescence-reflectance or dual digital systems. Quantitative image analysis is also one of the ways to improve objectivity and minimize observer errors. However, one of the most appropriate solutions would be the addition of AFI to narrow band imaging, and merging the two technologies into one videobronchoscope.

Evaluation of visualization of squamous cell carcinoma of esophagus and pharynx using an autofluorescence imaging videoendoscope system

BACKGROUND AND AIM

An autofluorescence imaging (AFI) videoendoscope system produces pseudo-color images combining autofluorescence and green reflectance, with the utility of this system previously confirmed for the diagnosis of bronchial squamous cell carcinoma (SCC). Our aim was to evaluate visualization of esophageal and pharyngeal SCC comparing AFI with white light endoscopy (WLE).

METHODS

Thirty-two patients with superficial esophageal SCC and 11 patients with superficial pharyngeal SCC diagnosed in other hospitals were enrolled in this prospective study. We observed the esophagus and pharynx with WLE followed by AFI and took both WLE and AFI images of the esophageal and pharyngeal SCC. Three experienced endoscopists subsequently evaluated the visualization quality of images from both systems on a three-tier scale: visible, illegible and invisible.

RESULTS

A total of 39 superficial esophageal SCC were diagnosed with 20, 11 and eight lesions classified as visible, illegible and invisible, respectively, by WLE compared to 31, three and five lesions, respectively, using AFI. Using AFI, 79% of superficial esophageal SCC lesions were visible, compared to only 51% with WLE (P < 0.05). In addition, 12 superficial pharyngeal SCC were diagnosed with four, five and three lesions considered as visible, illegible and invisible, respectively, using WLE in contrast to nine, three and 0 lesions, respectively, by AFI. Thus, using AFI, 75% of superficial pharyngeal SCC lesions were visible compared with only 33% with WLE (P = 0.13).

CONCLUSION

The AFI system appears to be more useful than WLE for early diagnosis of SCC of the esophagus and pharynx.

Centrally located squamous cell carcinoma of the lung mimicking endobronchial tuberculosis

Here we report a case of centrally located squamous cell carcinoma of the lung mimicking endobronchial tuberculosis. On the basis of the white light bronchoscopic (WLB) findings, bronchial tuberculosis was initially suspected. But transbronchial biopsy of the lesion revealed squamous cell carcinoma. Autofluorescence imaging bronchovideoscopy (AFI) showed the lesion area as magenta. After four cycles of chemotherapy, the magenta area was markedly shrunk on AFI. Performance of AFI might be useful for differentiating centrally located lung cancer from endobronchial tuberculosis.

Color fluorescence ratio for detection of bronchial dysplasia and carcinoma in situ

BACKGROUND

Autofluorescence bronchoscopy is more sensitive than conventional bronchoscopy for detecting early airway mucosal lesions. Decreased specificity can lead to excessive biopsy and increased procedural time. Onco-LIFE, a device that combines fluorescence and reflectance imaging, allows numeric representation by expressing red-to-green ratio (R/G ratio) within the region of interest. The aim of the study was to determine if color fluorescence ratio (R/G ratio) added to autofluorescence bronchoscopy could provide an objective means to guide biopsy.

METHODS

Subjects at risk for lung cancer were recruited at two centers: VU University Medical Centre (Amsterdam) and BC Cancer Agency (Canada). R/G ratio for each site appearing normal or abnormal was measured before biopsy. R/G ratios were correlated with pathology, and a receiver operating characteristic curve of R/G ratio for high-grade and moderate dysplasia was done. Following analysis of the training data set obtained from two centers, a prospective validation study was done.

RESULTS

Three thousand three hundred sixty-two adequate biopsies from 738 subjects with their corresponding R/G ratios were analyzed. R/G ratio 0.54 conferred 85% sensitivity and 80% specificity for the detection of high-grade and moderate dysplasia, area under the curve was 0.90, and 95% confidence interval was 0.88 to 0.92. In another 70 different sites that were assessed, kappa measurements of agreement of R/G ratios with visual scores and pathology were 0.66 (P < 0.0001) and 0.61 (P < 0.0001), respectively. R/G ratio combined with visual score improved specificity to 88% (95% confidence interval, 0.73-0.96) for high-grade and moderate dysplasia.

CONCLUSION

Color fluorescence ratio can objectively guide the bronchoscopist in selecting sites for biopsy with good pathologic correlation.

Autofluorescence videobronchoscopy (AFI) for the assessment of tumor extension in lung cancer

The major objective of our study was to determine the specificity and sensitivity of AFI videobronchoscopy vs. white light videobronchoscopy, in the assessment of lung cancer extent. Secondary objective was to investigate whether or not AFI can reveal greater extension of the tumor, and can it influence therapy making decision. Autofluorescence videobronchoscopy systems are new technology for visualization of bronchial mucosa, and the proper indications for such systems will be determined in the near future. In this prospective trial we have enrolled 27 patients with suspected lung cancer in whom we performed 108 diagnostic biopsies and 54 control biopsies. All patients underwent WL videobronchoscopy followed by Auto Fluorescence Imaging (AFI) examination of tracheobronchial tree. We were using videobronchoscope BF-F260 and EVIS LUCERA SPECTRUM processor unit. Overall specificity for AFI in the diagnostics of lung cancer was found to be 85%, sensitivity was 90%, positive predictive value (PPV) 78%, and negative predictive value (NPV) 94%. Specificity, sensitivity, PPV, and NPV for WL videobronchoscopy in lung cancer diagnostics were 54%, 64%, 51%, and 69%, respectively. Relative sensitivity ratio of AFI over WL videobronchoscopy, which is calculated to be 1.41, confirmed superiority of AFI in lung cancer diagnostics. We confirmed significant correlation between the greater extension of the tumor (assessed with AFI) and the therapeutical decision in lung cancer treatment (p = 0.01). Influence of AFI on therapeutical decision was significant (p = 0.034). AFI videobronchoscopy system yields significantly higher sensitivity and specificity for the assessment of lung cancer extent than WLB videobronchoscopy alone. It had shown to be able to influence therapeutic option for lung cancer treatment. Further studies are needed to evaluate and validate these results.

Detection and localization of intraepithelial neoplasia and invasive carcinoma using fluorescence-reflectance bronchoscopy: an international, multicenter clinical trial

OBJECTIVES

The primary objective of this study was to evaluate the benefit of using a new fluorescence-reflectance imaging system, Onco-LIFE, for the detection and localization of intraepitheal neoplasia and early invasive squamous cell carcinoma. A secondary objective was to evaluate the potential use of quantitative image analysis with this device for objective classification of abnormal sites.

DESIGN

This study was a prospective, multicenter, comparative, single arm trial. Subjects for this study were aged 45 to 75 years and either current or past smokers of more than 20 pack-years with airflow obstruction, forced expiratory volume in 1 second/forced vital capacity less than 75%, suspected to have lung cancer based on either sputum atypia, abnormal chest roentgenogram/chest computed tomography, or patients with previous curatively treated lung or head and neck cancer within 2 years.

MATERIALS AND METHODS

The primary endpoint of the study was to determine the relative sensitivity of white light bronchoscopy (WLB) plus autofluorescence-reflectance bronchoscopy compared with WLB alone. Bronchoscopy with Onco-LIFE was carried out in two stages. The first stage was performed under white light and mucosal lesions were visually classified. Mucosal lesions were classified using the same scheme in the second stage when viewed with Onco-LIFE in the fluorescence-reflectance mode. All regions classified as suspicious for moderate dysplasia or worse were biopsied, plus at least one nonsuspicious region for control. Specimens were evaluated by the site pathologist and then sent to a reference pathologist, each blinded to the endoscopic findings. Positive lesions were defined as those with moderate/severe dysplasia, carcinoma in situ (CIS), or invasive carcinoma. A positive patient was defined as having at least one lesion of moderate/severe dysplasia, CIS, or invasive carcinoma. Onco-LIFE was also used to quantify the fluorescence-reflectance response (based on the proportion of reflected red light to green fluorescence) for each suspected lesion before biopsy.

RESULTS

There were 115 men and 55 women with median age of 62 years. Seven hundred seventy-six biopsy specimens were included. Seventy-six were classified as positive (moderate dysplasia or worse) by pathology. The relative sensitivity on a per-lesion basis of WLB + FLB versus WLB was 1.50 (95% confidence interval [CI], 1.26-1.89). The relative sensitivity on a per-patient basis was 1.33 (95% CI, 1.13-1.70). The relative sensitivity to detect intraepithelial neoplasia (moderate/severe dysplasia or CIS) was 4.29 (95% CI, 2.00-16.00) and 3.50 (95% CI, 1.63-12.00) on a per-lesion and per-patient basis, respectively. For a quantified fluorescence reflectance response value of more than or equal to 0.40, a sensitivity and specificity of 51% and 80%, respectively, could be achieved for detection of moderate/severe dsyplasia, CIS, and microinvasive cancer.

CONCLUSIONS

Using autofluorescence-reflectance bronchoscopy as an adjunct to WLB with the Onco-LIFE system improves the detection and localization of intraepitheal neoplasia and invasive carcinoma compared with WLB alone. The use of quantitative image analysis to minimize interobserver variation in grading of abnormal sites should be explored further in future prospective clinical trial.

In vivo time-resolved spectroscopy of the human bronchial early cancer autofluorescence

Time-resolved measurements of tissue autofluorescence (AF) excited at 405 nm were carried out with an optical-fiber-based spectrometer in the bronchi of 11 patients. The objectives consisted of assessing the lifetime as a new tumor/normal (T/N) tissue contrast parameter and trying to explain the origin of the contrasts observed when using AF-based cancer detection imaging systems. No significant change in the AF lifetimes was found. AF bronchoscopy performed in parallel with an imaging device revealed both intensity and spectral contrasts. Our results suggest that the spectral contrast might be due to an enhanced blood concentration just below the epithelial layers of the lesion. The intensity contrast probably results from the thickening of the epithelium in the lesions. The absence of T/N lifetime contrast indicates that the quenching is not at the origin of the fluorescence intensity and spectral contrasts. These lifetimes (6.9 ns, 2.0 ns, and 0.2 ns) were consistent for all the examined sites. The fact that these lifetimes are the same for different emission domains ranging between 430 and 680 nm indicates that there is probably only one dominant fluorophore involved. The measured lifetimes suggest that this fluorophore is elastin.

Scanning single fiber endoscopy: a new platform technology for integrated laser imaging, diagnosis, and future therapies

Remote optical imaging of human tissue in vivo has been the foundation for the growth of minimally invasive medicine. This article describes a new type of endoscopic imaging that has been developed and applied to the human esophagus, pig bile duct, and mouse colon. The technology is based on a single optical fiber that is scanned at the distal tip of an ultrathin and flexible shaft that projects red, green, and blue laser light onto tissue in a spiral pattern. The resulting images are high-quality color video that is expected to produce future endoscopes that are thinner, longer, more flexible, and able to directly integrate the many recent advances of laser diagnostics and therapies.