Bronchoscopic navigation and tissue diagnosis

PneumaOCT: Pneumatic optical coherence tomography endoscopy for targeted distortion-free imaging in tortuous and narrow internal lumens

The complex anatomy of internal luminal organs, like bronchioles, poses challenges for endoscopic optical coherence tomography (OCT). These challenges include limited steerability for targeted imaging and nonuniform rotation distortion (NURD) with proximal scanning. Using rotary micromotors for distal scanning could address NURD but raises concerns about electrical safety and costs. We present pneumaOCT, the first pneumatic OCT endoscope, comprising a steerable catheter with a soft pneumatic actuator and an imaging probe with a miniature pneumatic turbine. With a diameter of 2.8 mm, pneumaOCT allows for a bending angle of up to 237°, facilitating navigation through narrow turns. The pneumatic turbine enables adjustable imaging speeds from 51 to 446 revolutions per second. We demonstrate the pneumaOCT in vivo imaging of mouse esophagus and colon, as well as targeted and distortion-free imaging of peripheral bronchioles in a bronchial phantom and a porcine lung. This advancement substantially improves endoscopic OCT for navigational imaging in curved and narrow lumens.

An alternative bronchoscopic transparenchymal nodule access by "invisible tunnel" technique under electromagnetic navigation without the transbronchial access tool

BACKGROUND

The diagnosis of peripheral pulmonary lesions (PPL) is still challenging. We describe a novel method for sampling PPL without bronchial signs by creating invisible tunnel under electromagnetic navigation without the transbronchial access tool (TABT).

METHODS

During electromagnetic navigation, we adjust the angle of the edge extended working channel catheter based on the real-time position of the lesion in relation to the locating guide rather than preset route. A biopsy brush or biopsy forceps is used to punch a hole in the bronchial wall. A locating guide is then re-inserted to real-time navigate through the lung parenchyma to the lesion. Safety and feasibility of this method was analyzed.

RESULTS

A total of 32 patients who underwent electromagnetic navigation bronchoscopy were retrieved. The mean size of the lesion is 23.1 mm. The mean operative time of all patients was 12.4 min. Ten of the patients did not have a direct airway to the lesion, thus creating an invisible tunnel. For them, the length of the tunnel from the bronchial wall POE to the lesion was 11-30 mm, with a mean length of 16.9 mm and a mean operation time of 14.1 min. Adequate samples were obtained from 32 patients (100%), and the diagnostic yield was 87.5% (28/32). Diagnostic yield of with create the invisible tunnel TBAT was 90% (9/10), and one patient undergone pneumothorax after operation.

CONCLUSIONS

This method is feasible and safe as a novel approach sampling pulmonary lesions without bronchial signs, and it further improves current tunnel technique.

CT-guided needle biopsy is not associated with increased ipsilateral pleural metastasis

INTRODUCTION

Histological confirmation of a lung tumor is the prerequisite for treatment planning. It has been suspected that CT-guided needle biopsy (CTGNB) exposes the patient to a higher risk of pleural recurrence. However, the distance between tumor and pleura has largely been neglected as a possible confounder when comparing CTGNB to bronchoscopy.

METHODS

All patients with lung cancer histologically confirmed by bronchoscopy or CTGNB between 2010 and 2020 were enrolled and studied. Patients' medical histories, radiologic and pathologic findings and surgical records were reviewed. Pleural recurrence was diagnosed by pleural biopsy, fluid cytology, or by CT chest imaging showing progressive pleural nodules.

RESULTS

In this retrospective unicenter analysis, 844 patients underwent curative resection for early-stage lung cancer between 2010 and 2020. Median follow-up was 47.5 months (3-137). 27 patients (3.2 %) with ipsilateral pleural recurrence (IPR) were identified. The distance of the tumor to the pleura was significantly smaller in patients who underwent CTGNB. A tendency of increased risk of IPR was observed in tumors located in the lower lobe (HR: 2.18 [±0.43], p = 0.068), but only microscopic pleural invasion was a significant independent predictive factor for increased risk of IPR (HR: 5.33 [± 0.51], p = 0.001) by multivariate cox analysis. Biopsy by CTGNB did not affect IPR (HR: 1.298 [± 0.39], p = 0.504).

CONCLUSION

CTGNB is safe and not associated with an increased incidence of IPR in our cohort of patients. This observation remains to be validated in a larger multicenter patient cohort.

Early comparison robotic bronchoscopy versus electromagnetic navigational bronchoscopy for biopsy of pulmonary nodules in a thoracic surgery practice

Pulmonary nodules are frequently encountered in high-risk patients. Often these require biopsy which can be challenging. We relate our experience comparing use of electromagnetic navigational bronchoscopy (ENB) to a robotic bronchoscopy system (RB). A retrospective review of patients undergoing bronchoscopic biopsy from 2015 to 2021. The timeframe overlapped with transition from ENB using Veran SPiN system to RB using Ion system by Intuitive. Patient and nodule characteristics were collected. Primary end point was overall diagnostic yield which was defined by pathologic confirmation of malignancy or benign finding. Secondary outcomes included diagnostic yield based on overall size of nodules and need for further work up and testing. 116 patients underwent ENB or RB of 134 nodules. No perioperative complications occurred. Diagnostic yield of ENB was 49.5% (41/91 nodules) versus 86.1% (37/43 nodules) for RB. Average nodule size for ENB was 2.55 cm versus 1.96 cm for RB. When divided based on size, ENB had a 30% diagnostic yield for nodules 1-2 cm (11/37 nodules, mean size 1.46 cm) and 64% yield for nodules 2-3 cm (14/22 nodules, mean size 2.38 cm). RB had an 81% yield for nodules 1-2 cm (mean size 1.41 cm) and 100% yield for nodules 2-3 cm (mean 2.3 cm). RB showed superiority over ENB in early implementation trials for biopsy of suspicious pulmonary nodules. It is a safe technology allowing for increased access to all lung fields and utilization in the thoracic surgical practice will be paramount to advancing the field.

Virtual bronchoscopic navigation with intraoperative cone-beam CT for the diagnosis of peripheral pulmonary nodules

OBJECTIVE

Transbronchial biopsy is a safe manner with fewer complications than percutaneous transthoracic needle biopsy; however, the current diagnostic yield is still necessitating further improvement. We aimed to evaluate the diagnostic yield of using virtual bronchoscopic navigation (VBN) and cone-beam CT (CBCT) for transbronchial biopsy and to investigate the factors that affected the diagnostic sensitivity.

METHODS

We retrospectively investigated 255 patients who underwent VBN-CBCT-guided transbronchial biopsy at our two centers from May 2021 to April 2022. A total of 228 patients with final diagnoses were studied. Patient characteristics including lesion size, lesion location, presence of bronchus sign, lesion type and imaging tool used were collected and analyzed. Diagnostic yield was reported overall and in groups using different imaging tools.

RESULTS

The median size of lesion was 21 mm (range of 15.5-29 mm) with 46.1% less than 2 cm in diameter. Bronchus sign was present in 87.7% of the patients. The overall diagnostic yield was 82.1%, and sensitivity for malignancy was 66.3%. Patients with lesion > 2 cm or with bronchus sign were shown to have a significantly higher diagnostic yield. Four patients had bleeding and no pneumothorax occurred.

CONCLUSION

Guided bronchoscopy with VBN and CBCT was an effective diagnostic method and was associated with a high diagnostic yield in a safe manner. In addition, the multivariant analysis suggested that lesion size and presence of bronchus sign could be a predictive factor for successful bronchoscopic diagnosis.

Comparison of Synapse 3D system (Version 4.4) and DirectPath system (Version 2.0) in virtual bronchoscopic navigation application for peripheral pulmonary nodules

BACKGROUND

Differences between virtual bronchoscopic navigation (VBN) systems and their impacts on the diagnostic yield of transbronchial biopsy (TBB) of peripheral pulmonary nodules (PPNs) remain unclear.

OBJECTIVES

To compare the Synapse 3D system (Version 4.4, Fujifilm, Japan) and DirectPath system (Version 2.0, Olympus, Japan) in the VBN application of PPNs.

DESIGN

Retrospective study with self-paired design and exploratory study with retrospective cohort design.

METHODS

The study analyzed patients with PPNs using the Synapse 3D system (Group S) and DirectPath system (Group D) and compared differences between the two groups in bronchial tree reconstruction, navigation pathway planning, and VBN-assisted TBB of PPNs.

RESULTS

In all, 289 patients were analyzed ultimately. Bronchial tree reconstruction quality was better in Group S (p < 0.001). Navigation pathway planning duration in Group S was longer than that in Group D (median 1.35 vs 1.04 s, p < 0.001). Automated navigation pathway planning success rate in Group S was higher than that in Group D (36.7% vs 19.7%, p < 0.001), and CT image reconstruction parameter and nodule diameter, bronchus sign, and distance from the hilum had significant effects on it in both groups. Fifty-six patients in Group S and forty-two patients in Group D were analyzed ultimately. The localization success rate and diagnostic yield of PPNs between the two groups were not significantly different (85.3% vs 91.2% and 67.6% vs 61.8%, respectively, p > 0.05).

CONCLUSION

Synapse 3D system (Version 4.4) and DirectPath system (Version 2.0) had their own merits. Localization success rate and diagnostic yield of VBN-assisted TBB were of no statistical difference for these two VBN systems. Improvements in segmentation algorithms of VBN systems and using the most suitable chest CT scan data for them may be the breakthrough to improve the efficiency of VBN, especially for poor experienced interventional physicians.

Artificial intelligence in interventional pulmonology

PURPOSE OF REVIEW

In recent years, there has been remarkable progress in the field of artificial intelligence technology. Artificial intelligence applications have been extensively researched and actively implemented across various domains within healthcare. This study reviews the current state of artificial intelligence research in interventional pulmonology and engages in a discussion to comprehend its capabilities and implications.

RECENT FINDINGS

Deep learning, a subset of artificial intelligence, has found extensive applications in recent years, enabling highly accurate identification and labeling of bronchial segments solely from intraluminal bronchial images. Furthermore, research has explored the use of artificial intelligence for the analysis of endobronchial ultrasound images, achieving a high degree of accuracy in distinguishing between benign and malignant targets within ultrasound images. These advancements have become possible due to the increased computational power of modern systems and the utilization of vast datasets, facilitating detections and predictions with greater precision and speed.

SUMMARY

Artificial intelligence integration into interventional pulmonology has the potential to enhance diagnostic accuracy and patient safety, ultimately leading to improved patient outcomes. However, the clinical impacts of artificial intelligence enhanced procedures remain unassessed. Additional research is necessary to evaluate both the advantages and disadvantages of artificial intelligence in the field of interventional pulmonology.

Two-stage contextual transformer-based convolutional neural network for airway extraction from CT images

Accurate airway segmentation from computed tomography (CT) images is critical for planning navigation bronchoscopy and realizing a quantitative assessment of airway-related chronic obstructive pulmonary disease (COPD). Existing methods face difficulty in airway segmentation, particularly for the small branches of the airway. These difficulties arise due to the constraints of limited labeling and failure to meet clinical use requirements in COPD. We propose a two-stage framework with a novel 3D contextual transformer for segmenting the overall airway and small airway branches using CT images. The method consists of two training stages sharing the same modified 3D U-Net network. The novel 3D contextual transformer block is integrated into both the encoder and decoder path of the network to effectively capture contextual and long-range information. In the first training stage, the proposed network segments the overall airway with the overall airway mask. To improve the performance of the segmentation result, we generate the intrapulmonary airway branch label, and train the network to focus on producing small airway branches in the second training stage. Extensive experiments were performed on in-house and multiple public datasets. Quantitative and qualitative analyses demonstrate that our proposed method extracts significantly more branches and longer lengths of the airway tree while accomplishing state-of-the-art airway segmentation performance. The code is available at https://github.com/zhaozsq/airway_segmentation.

Phenomic Studies on Diseases: Potential and Challenges

The rapid development of such research field as multi-omics and artificial intelligence (AI) has made it possible to acquire and analyze the multi-dimensional big data of human phenomes. Increasing evidence has indicated that phenomics can provide a revolutionary strategy and approach for discovering new risk factors, diagnostic biomarkers and precision therapies of diseases, which holds profound advantages over conventional approaches for realizing precision medicine: first, the big data of patients' phenomes can provide remarkably richer information than that of the genomes; second, phenomic studies on diseases may expose the correlations among cross-scale and multi-dimensional phenomic parameters as well as the mechanisms underlying the correlations; and third, phenomics-based studies are big data-driven studies, which can significantly enhance the possibility and efficiency for generating novel discoveries. However, phenomic studies on human diseases are still in early developmental stage, which are facing multiple major challenges and tasks: first, there is significant deficiency in analytical and modeling approaches for analyzing the multi-dimensional data of human phenomes; second, it is crucial to establish universal standards for acquirement and management of phenomic data of patients; third, new methods and devices for acquirement of phenomic data of patients under clinical settings should be developed; fourth, it is of significance to establish the regulatory and ethical guidelines for phenomic studies on diseases; and fifth, it is important to develop effective international cooperation. It is expected that phenomic studies on diseases would profoundly and comprehensively enhance our capacity in prevention, diagnosis and treatment of diseases.

Innovative Invasive Loco-Regional Techniques for the Treatment of Lung Cancer

Surgical resection is still the standard treatment for early-stage lung cancer. A multimodal treatment consisting of chemotherapy, radiotherapy and/or immunotherapy is advised for more advanced disease stages (stages IIb, III and IV). The role of surgery in these stages is limited to very specific indications. Regional treatment techniques are being introduced at a high speed because of improved technology and their possible advantages over traditional surgery. This review includes an overview of established and promising innovative invasive loco-regional techniques stratified based on the route of administration, including endobronchial, endovascular and transthoracic routes, a discussion of the results for each method, and an overview of their implementation and effectiveness.

Non‑diagnostic electromagnetic navigation bronchoscopy biopsy: Predictive factors and final diagnoses

The present study aimed to explore the final diagnosis of pulmonary nodules with an initial non-diagnostic result on electromagnetic navigation bronchoscopy (ENB) biopsy and the predictive factors for a non-diagnostic result. A total of 198 nodules from 194 patients that were suspected to be malignant tumors were included in the present study. The initial biopsy pathology results were divided into two groups: The diagnostic group and the non-diagnostic group. The diagnostic group was defined as a successful initial biopsy to obtain a diagnosis, including malignant and benign diagnoses. The non-diagnostic group was defined as a non-specific benign diagnosis, normal lung tissue or an unsuccessful biopsy. Among the 198 nodules, 139 (70.2%) were in the diagnostic group and 59 (29.8%) were in the non-diagnostic group. Predictive factors for a non-diagnostic biopsy included nodule size ≤1.5 cm [odds ratio (OR), 2.05; 95% confidence interval (CI), 1.03-4.09], non-solid nodules (OR, 2.71; 95% CI, 1.33-5.64) and nodules in the left lung (OR, 2.50; 95% CI, 1.27-4.92). Of the 59 non-diagnostic biopsies, 46 were finally confirmed to be malignant by surgery. Notably, non-diagnostic biopsies with non-solid nodules (OR, 7.64; 95% CI, 3.11-18.76) were more likely to be malignant. In conclusion, the predictive factors for a non-diagnostic biopsy were nodule size ≤1.5 cm and non-solid nodules. It was not rare for patients to finally be diagnosed with a malignancy in the non-diagnostic group. Therefore, care should be taken when the results of an ENB are non-diagnostic to prevent misdiagnosis.

Photodynamic therapy to a primary cancer of the peripheral lung: Case report

Photodynamic therapy (PDT) is an FDA approved treatment for lung cancer. In the United States the photosensitizer porfimer sodium (Photofrin®, Pinnacle Biologics) is intravenously introduced at 2mg/kg. After approximately 48 h, illumination to activate the photosensitizer is initiated, with 630nm red light at 200J/cm, delivered by fiber-optic catheter, brought to the tumor endo- bronchially, and delivered for 500 s. This will create, in the presence of oxygen, a Type II Photodynamic Reaction (PDR) which generates singlet oxygen species that are tumor ablative. Classically, PDT for lung cancer has been employed for symptomatic central and obstructing tumors with great success. This case report describes an innovative approach to treat a peripheral, early stage lung cancer employing magnetic navigation and endobronchial treatment. We report on a 79 year old male with numerous comorbidities including pulmonary fibrosis, who was found to have a biopsy proven peripheral and solitary non-small cell cancer. Due to prior SBRT (stereotactic body radiation therapy) with dose levels causing radiation fibrosis, he was not a candidate for repeat SBRT, and he was not a surgical candidate due to comorbidities. Tumor control with PDT was achieved without treatment related morbidity. This report details our findings.

Advances in diagnostic tools for respiratory tract infections: from tuberculosis to COVID-19 - changing paradigms?

Respiratory tract infections (RTIs) are one of the most common reasons for seeking healthcare, but are amongst the most challenging diseases in terms of clinical decision-making. Proper and timely diagnosis is critical in order to optimise management and prevent further emergence of antimicrobial resistance by misuse or overuse of antibiotics. Diagnostic tools for RTIs include those involving syndromic and aetiological diagnosis: from clinical and radiological features to laboratory methods targeting both pathogen detection and host biomarkers, as well as their combinations in terms of clinical algorithms. They also include tools for predicting severity and monitoring treatment response. Unprecedented milestones have been achieved in the context of the COVID-19 pandemic, involving the most recent applications of diagnostic technologies both at genotypic and phenotypic level, which have changed paradigms in infectious respiratory diseases in terms of why, how and where diagnostics are performed. The aim of this review is to discuss advances in diagnostic tools that impact clinical decision-making, surveillance and follow-up of RTIs and tuberculosis. If properly harnessed, recent advances in diagnostic technologies, including omics and digital transformation, emerge as an unprecedented opportunity to tackle ongoing and future epidemics while handling antimicrobial resistance from a One Health perspective.

Contemporary Concise Review 2021: Pulmonary nodules from detection to intervention

The US Preventive Task Force (USPSTF) has updated screening criteria by expanding age range and reducing smoking history required for eligibility; the International Lung Screen Trial (ILST) data have shown that PLCOM2012 performs better for eligibility than USPSTF criteria. Screening adherence is low (4%-6% of potential eligible candidates in the United States) and depends upon multiple system and patient/candidate-related factors. Smoking cessation in lung cancer improves survival (past prospective trial data, updated meta-analysis data); smoking cessation is an essential component of lung cancer screening. Circulating biomarkers are emerging to optimize screening and early diagnosis. COVID-19 continues to affect lung cancer treatment and screening through delays and disruptions; specific operational challenges need to be met. Over 70% of suspected malignant lesions develop in the periphery of the lungs. Bronchoscopic navigational techniques have been steadily improving to allow greater accuracy with target lesion approximation and therefore diagnostic yield. Fibre-based imaging techniques provide real-time microscopic tumour visualization, with potential diagnostic benefits. With significant advances in peripheral lung cancer localization, bronchoscopically delivered ablative therapies are an emerging field in limited stage primary and oligometastatic disease. In advanced stage lung cancer, small-volume samples acquired through bronchoscopic techniques yield material of sufficient quantity and quality to support clinically relevant biomarker assessment.

Predictors of Success When Implementing an Electromagnetic Navigational Bronchoscopy Program

INTRODUCTION

With the advent of lung cancer screening, lung nodules are being discovered at an increasing rate. With improvements in transbronchial biopsy technology, it is important for thoracic surgeons to be involved with diagnostic procedures. The aim of this project is to relate the thoracic surgeon experience in implementing an electromagnetic navigational bronchoscopy (ENB) program at our institution and describe the factors that led to successful navigation (the ability to position a biopsy instrument in range for biopsy) and diagnostic biopsy of nodules.

METHODS

The thoracic surgery ENB program was initiated in 2014. A retrospective analysis of patients referred to thoracic surgery from 2014 to 2019 for lung nodule evaluation was performed. Patients who underwent ENB and biopsy were included. Recursive partitioning (CART) and multivariable regression analyses were used to identify predictors of successful navigation and biopsy.

RESULTS

There were 73 patients who underwent ENB evaluation of 91 nodules from 2014 to 2019. There was successful navigation in 75.8% of nodules, and on multivariable analysis, bronchus sign, lesion size, and pleural distance were significant predictors of successful navigation. Of the lesions that had successful navigation, 65.2% had a diagnostic biopsy. Based on CART analysis, positive bronchus sign and lesion size ≥ 1.3 cm were most predictive of obtaining a diagnostic biopsy with a probability of 0.75.

CONCLUSIONS

Nodule size, distance to the pleura, and bronchus size are independent variables of successful navigation when using ENB. However, of the lesions that were successfully reached, combined lesion size >1.3 cm and a positive bronchus sign were most predictive of obtaining a diagnostic biopsy. These factors should be considered when implementing an ENB program in a thoracic surgery practice.

Intraoperative margin assessment by wireless signals in thoracoscopic anterior (S3) segmentectomy using a radiofrequency identification marker

Despite the use of near-infrared thoracoscopy with intravenous indocyanine green, intraoperative assessment of the surgical margin for the resection of non-palpable tumors located near the intersegmental plane requires highly advanced surgical skill for the prevention of local recurrence. Because the demarcation line is limited to the pleural surface, to overcome uncertainty in tumor palpation for deeply located small-sized lesions, other supplemental localization techniques have been proposed. Here, we present a novel surgical technique using radiofrequency identification markers for intraoperative assessment of the lateral surgical margin in segmentectomy.

Validity of surgical decision based on intraoperative frozen section diagnosis for unconfirmed pulmonary nodules with previous malignancy

OBJECTIVES

The lung is a major target organ of metastasis in several cancers. To distinguish primary lung cancer from pulmonary metastases is a clinical challenge. Small pulmonary nodules (PNs) are frequently diagnosed by frozen section diagnosis (FSD) intraoperatively after resection. Intraoperative FSD is very important to determine the extent of subsequent surgical procedures. This study aimed to know the validity of surgical decision based on FSD for preoperatively unconfirmed PN with previous malignancy.

METHODS

We retrospectively evaluated 96 patients with suspected malignant PN who underwent intraoperative FSD between 2018 and 2020. Intraoperative FSD, final diagnosis, and surgical procedure data were examined.

RESULTS

Surgical procedure adequacy, based on FSD for preoperatively unconfirmed PN with previous malignancy, was 91% (88/96). The overall diagnostic accuracy of FSD was 83.3% (80/96). Discrepancy was noted in two cases (2.1%), and conclusive diagnosis could not be reached intraoperatively in 14 cases (14.6%). A second surgery was required in three patients and no additional excision for primary lung cancer was performed in three patients. Conversely, there were three cases of over-surgery, namely, lobectomy for pulmonary metastasis.

CONCLUSIONS

Surgical decision-making based on FSD for preoperatively unconfirmed PN in patients with previous malignancy was generally adequate. However, there were inadequate or excessive surgical procedures due to limitations in the accuracy of intraoperative FSD. Improving the accuracy of intraoperative FSD is a necessary step for obtaining adequate surgical decision-making and precision medicine.

Photodynamic Theranostics of Central Lung Cancer: Capabilities of Early Diagnosis and Minimally Invasive Therapy (Review)

The aim of the study was to assess the prospects for central lung cancer (CLC) screening using fluorescent diagnostics and its treatment by endobronchial photodynamic therapy (PDT). Bronchoscopic fluorescent diagnostics using chlorin e6 photosensitizers and a developed instrumental system enable to reveal tumor changes in large bronchi mucosa at early stages, and a developed PDT technique performed under fluorescent control helps achieve personalized treatment. Such an approach is considered as a theranostic technique - photodynamic theranostics. central lung cancer screening requires a fluorescent dye characterized by availability and can be used directly within the examination. Indocyanine green can be used as a dye, its peculiarity is the necessity to excite and record fluorescence in the near-infrared (NIR) wavelength band. First experiments using NIR bands to diagnose a bronchoscopic system showed the detectability of tumor areas using on-site bronchoscopic photodynamic theranostics, which consists in NIR imaging of tumor foci when a standard dose of indocyanine green is administered during the examination.

Conclusion

Further progress of early diagnostics and minimally invasive CLC therapy will be determined by the development of new photosensitizers, which should be characterized by a high absorption band in NIR area, quick accumulation in a tumor, high yield of single oxygen in NIR illumination, bright fluorescence, high potential in terms of the induction of an anti-tumor immune response.

Advanced Bronchoscopic Technologies for Biopsy of the Pulmonary Nodule: A 2021 Review

The field of interventional pulmonology (IP) has grown from a fringe subspecialty utilized in only a few centers worldwide to a standard component in advanced medical centers. IP is increasingly recognized for its value in patient care and its ability to deliver minimally invasive and cost-effective diagnostics and treatments. This article will provide an in-depth review of advanced bronchoscopic technologies used by IP physicians focusing on pulmonary nodules. While most pulmonary nodules are benign, malignant nodules represent the earliest detectable manifestation of lung cancer. Lung cancer is the second most common and the deadliest cancer worldwide. Differentiating benign from malignant nodules is clinically challenging as these entities are often indistinguishable radiographically. Tissue biopsy is often required to discriminate benign from malignant nodule etiologies. A safe and accurate means of definitively differentiating benign from malignant nodules would be highly valuable for patients, and the medical system at large. This would translate into a greater number of early-stage cancer detections while reducing the burden of surgical resections for benign disease. There is little high-grade evidence to guide clinicians on optimal lung nodule tissue sampling modalities. The number of novel technologies available for this purpose has rapidly expanded over the last decade, making it difficult for clinicians to assess their efficacy. Unfortunately, there is a wide variety of methods used to determine the accuracy of these technologies, making comparisons across studies impossible. This paper will provide an in-depth review of available data regarding advanced bronchoscopic technologies.

Electromagnetic bronchoscopy guided microwave ablation for early stage lung cancer presenting as ground glass nodule

Background

Patients with early-stage lung cancer are sometimes medically inoperable, and for patients with multiple primary lung cancers, surgical resection alone sometimes proves to be impractical. Local treatments like microwave ablation (MWA) are investigational alternatives for these patients. Most reported MWA procedures for lung cancers are performed percutaneously under CT guidance. MWA navigated by electromagnetic bronchoscopy (ENB) has been limitedly studied. In this study, we aimed to evaluate the safety and feasibility of MWA under ENB guidance in patients with inoperable early-stage lung cancers or multiple primary lung cancers which cannot be completely resected.

Methods

From June 2019 to December 2020, preliminary attempts of ENB-guided MWA were made in five medically inoperable patients with a single early-stage lung cancer and ten patients with multiple primary lung cancers which were difficult to resect at the same time. For patients with concomitant pulmonary nodules which needed surgical resection, thoracoscopic resections were performed following ENB-guided MWA. The safety, feasibility, and technique effectiveness of treatments were evaluated.

Results

ENB-guided MWA for 15 ground glass nodules (GGNs) in 15 patients was completed in accordance with the planned protocol. Biopsy of 13 GGNs showed malignancy. Five patients received simple ENB-guided MWA without simultaneous surgical resection and ten patients received simultaneous surgical resection for 13 concomitant pulmonary nodules. CT scan by the first postoperative week showed technique effectiveness of ablation for 11 nodules indicated for MWA. Four patients had mild complications after the procedure and recovered shortly after treatment.

Conclusions

For medically inoperable patients with a single GGN manifesting early-stage lung cancer and patients with multiple primary early-stage lung cancers which cannot be resected at the same time, ENB-guided MWA might be a safe and feasible alternative local treatment, whether combined with surgical resection or not. However, large, prospective, randomized, multicenter studies are needed to confirm its role in the treatment of early-stage lung cancer.

Diversity of lymphatic flow in patients with lung cancer revealed by computed tomography lymphography

OBJECTIVES

This study was conducted to verify the optimal extent of lymph node dissection or sampling during lung cancer surgery based on the sentinel node (SN) map created by computed tomography (CT) lymphography.

METHODS

From April 2010 to January 2015, patients with clinical stage I non-small-cell lung cancer, who were candidates for lobectomy or segmentectomy with standard hilar and mediastinal lymph node dissection, and in whom bronchus reached the tumour, were enrolled. An ultrathin bronchoscope was inserted to the target bronchus under the guidance of virtual bronchoscopic navigation images. CT images of the chest were obtained 30 s after 2.5 ml of iopamidol was injected. SNs were identified when the maximum CT attenuation value of the lymph nodes on postcontrast CT images increased by 30 Hounsfield units or more compared with the precontrast images. Patients underwent lobectomy with standard lymph node dissection.

RESULTS

SNs were identified in 36 (87.8%) of the 41 patients. The average number of SNs was 1.6 (range, 1-4). There was 1 false negative case; therefore, the accuracy of SN identification was 97.2% (35/36). In 5 (13.9%) of 36 patients, SNs were outside the lobe-specific lymph node station range (#11i from right S1, #7 from right S1, #4R from right S8, #12u from right S8, #7 and #12l from left S1 + 2).

CONCLUSIONS

CT lymphography demonstrated the diversity of lymphatic spreading patterns and there were cases in which lymph flows are found outside the lymph node dissection range.

The LungVision navigational platform for peripheral lung nodule biopsy and the added value of cryobiopsy

BACKGROUND

The LungVision system is a novel augmented-fluoroscopy-based real-time navigation and guidance technology for bronchoscopy that can be integrated with any standard biopsy tool, including the cryoprobe, to enable real-time visualization and localization of pulmonary nodules.

OBJECTIVES

To evaluate the diagnostic yield and safety among patients undergoing peripheral pulmonary nodule biopsy with the LungVision system.

METHODS

This prospective, single-center study was conducted at Rabin Medical Center in Israel. All patients that underwent peripheral pulmonary nodule biopsy with the LungVision system from January 2016 to August 2020 were included. All procedures were performed under moderate sedation. The primary outcome was tissue diagnosis by either identification of malignant cells or benign diagnosis. Secondary outcomes were safety and the added value of cryobiopsy.

RESULTS

Sixty-three procedures were performed during the study period. Median lesion size (interquartile range) was 25.0 mm (18-28 mm). The diagnostic yield overall was 27/33 (81.8%) and for lesions smaller than 20 mm was 13/18 (72.2%). In nine cases the transbronchial cryobiopsy showed tissue with malignant cells that were not found in any other biopsy material taken with other sampling tools. One patient was treated with a chest tube for a pneumothorax. No other major complications were reported.

CONCLUSIONS

The LungVision system showed good feasibility and safety for peripheral pulmonary nodule biopsy. The system is compatible with all biopsy tools, including the cryoprobe. Randomized controlled trials are needed to accurately ascertain its diagnostic yield.

Bronchoscopic biopsy of peripheral pulmonary lesions in 2020: a review of existing technologies

There are over 200,000 new cases of lung cancer diagnosed annually in the United States resulting in nearly 150,000 deaths, making lung cancer the most lethal of all forms of cancer. Only 1 in 6 lung cancers are diagnosed at an early stage an over half are diagnosed with distant metastasis. Despite advances in screening and treatment, the 5-year survival rate for all lung cancers remains low, around 20%. The advent of effective lung cancer screening with low-dose computed tomography has started to shift diagnosis to earlier stages. Screening, along with the ever-increasing use of chest CT, have led to an exponential increase in the detection of indeterminate lung nodules. For many nodules, effective diagnosis relies on invasive tissue sample collection. Advances in bronchoscopic technology have allowed for safe and increasingly effective tissue diagnosis of these nodules; however, inconsistencies across studies evaluating diagnostic yield remain. This review will provide an overview of the advanced bronchoscopic technologies currently in wide use, the quality of data supporting their use, some of the perceived weaknesses and strengths of each technology, and introduce promising emerging diagnostic platforms poised to advance the field. Ultimately, quality comparative research is needed to accurately characterize the diagnostic test performance of currently available bronchoscopic platforms, improve the efficacy of bronchoscopy-generated diagnostic yields while maintaining, their strong safety profile.

The value of navigation bronchoscopy in the diagnosis of peripheral pulmonary lesions: A meta-analysis

Background

To compare the diagnostic yield of peripheral pulmonary lesions (PPLs) with and without navigation system.

Methods

Studies dating from January 1990 to October 2019 were collected from databases. Diagnostic yield of navigation bronchoscopy and non‐navigation bronchoscopy was extracted from comparative studies. Subgroup analysis was adopted to test diagnostic yield variation by lesion size, lobe location of the lesion, distance from the hilum, bronchus sign and nature of the lesion.

Results

In total, 2131 patients from 10 studies were enrolled into the study. Diagnostic yield of navigation bronchoscopy was statistically higher than non‐navigation bronchoscopy for PPLs (odds ratio [OR] 1.69, 95% confidence interval [CI] 1.32, 2.18, P < 0.001), particularly for PPLs in the peripheral third lung (OR 2.26, 95% CI 1.48, 3.44, P < 0.001) and for bronchus sign positive PPLs (OR 2.26, 95% CI 1.21, 4.26, P = 0.011). Navigation bronchoscopy had better performance than non‐navigation bronchoscopy when PPLs were ≤ 20 mm (OR 2.09, 95% CI 1.44, 3.03, P < 0.001). It also elevated diagnostic yield of malignant PPLs (OR 1.67, 95% CI 1.26, 2.22, P < 0.001) and PPLs in the bilateral upper lobes (OR 1.50, 95% CI 1.09, 2.08, P = 0.014).

Conclusions

Navigation bronchoscopy enhanced diagnostic yield when compared to non‐navigation bronchoscopy, particularly for PPLs in the peripheral third lung, PPLs being bronchus sign positive, PPLs ≤ 20 mm, malignant PPLs and PPLs in the bilateral upper lobes.

Key points

The current study provided systematic evaluation on the diagnostic value of navigation bronchoscopy by comparing it with non‐navigation bronchoscopy, and exploring the factors affecting the diagnostic yield.