Electromagnetic navigational bronchoscopy in the diagnosis of lung lesions

Diagnostic accuracy of imaging-guided biopsy of peripheral pulmonary lesions: a systematic review

The histologic definition of peripheral pulmonary lesion (PPL) is critical for a correct diagnosis and appropriate therapy. Non-invasive techniques for PPL biopsy are imaging-guided, using endobronchial ultrasound (EBUS), computed tomography (CT), and electromagnetic navigation bronchoscopy (ENB). To assess the diagnostic accuracy of PPL biopsy and provide a framework for reporting data for accuracy studies of PPL biopsy. A systematic review was conducted on PubMed, Scopus, and Web of Science to identify all the articles assessing the accuracy of EBUS, CT, and ENB between January 2000 and June 2023 basing search queries on keywords emerging from PICO question. Only studies investigating biopsy of PPL and reporting accuracy or necessary data to calculate it independently were included. Risk of bias was based on QUADAS-2 tool. In total, 81 studies were included. Median accuracy was 0.78 (range=0.51-0.94) in the EBUS group, 0.91 (range=0.73-0.97) in the CT group, 0.72 (range=0.59-0.97) in the ENB group, and 0.77 (range=0.61-0.92) in the combined group. Sensitivity and NPV ranges were 0.35-0.94 and 0.26-0.88 in the EBUS group, 0.71-0.97 and 0.46-1.00 in the CT group, 0.55-0.96 and 0.32-0.90 in the ENB group, and 0.70-0.90 and 0.28-0.79 in the combined group. Specificity and PPV were 1.00 in almost all studies. Overall complication rate was 3%, 30%, 8%, and 5% in the EBUS, CT, ENB, and combined groups. CT-guided biopsy was the most accurate technique, although with the highest complication rate. When calculating accuracy, indeterminate results must be considered false negatives according to the "intention-to-diagnose" principle.

The effect of combining different sampling tools on the performance of electromagnetic navigational bronchoscopy for the evaluation of peripheral lung lesions and factors associated with its diagnostic yield

BACKGROUND

We assessed the performance of Electromagnetic navigational bronchoscopy (ENB) as a standalone diagnostic technique and the performance of different sampling tools used during the procedure.

METHODS

We recruited 160 consecutive patients who underwent ENB for peripheral lung lesions (PLL) at a tertiary care centre. The diagnostic performance of ENB and sampling tools was assessed using a logistic regression model and a ROC-curve in which the dependent variable was diagnostic success. A multivariate model was built to predict diagnostic success before performing ENB to select the best candidates for the procedure.

RESULTS

Most patients with PLLs in the study were male (65%), with a mean age of 67.9 years. The yield was 66% when the most common techniques were used together as suction catheter + transbronchial biopsy forceps (TBBx) + bronchoalveolar lavage + bronchial washing (p < 0.001) and increased to 69% when transbronchial needle aspiration (TBNA) and cytology brush were added (p < 0.001). Adding diagnostic techniques such as TBBx and TBNA resulted in an increase in diagnostic performance, with a statistically significant trend (p = 0.002). The logistic model area-under the ROC-curve for diagnostic success during ENB was 0.83 (95% CI:0.75-0.90; p < 0.001), and a logit value ≥ 0.12 was associated with ≥ 50% probability of diagnostic success.

CONCLUSIONS

ENB, as a stand-alone diagnostic tool for the evaluation of PLLs when performed by experienced operators using a multi-modality technique, has a good diagnostic yield. The probability of having a diagnostic ENB could be assessed using the proposed model.

Guided Bronchoscopy for the Evaluation of Pulmonary Lesions: An Updated Meta-analysis

BACKGROUND

Guided bronchoscopy is increasingly used to diagnose peripheral pulmonary lesions (PPLs). A meta-analysis published in 2012 demonstrated a pooled diagnostic yield of 70%; however, recent publications have documented yields as low as 40% and as high as 90%.

RESEARCH QUESTION

Has the diagnostic yield of guided bronchoscopy in patients with PPLs improved over the past decade?

STUDY DESIGN AND METHODS

A comprehensive search was performed of studies evaluating the diagnostic yield of differing bronchoscopic technologies used to reach PPLs. Study quality was assessed using the Quality assessment of diagnostic accuracy of studies (QUADAS-2) assessment tool. Number of lesions, type of technology used, overall diagnostic yield, and yield by size were extracted. Adverse events were recorded. Meta-analytic techniques were used to summarize findings across all studies.

RESULTS

A total of 16,389 lesions from 126 studies were included. There was no significant difference in diagnostic yield prior to 2012 (39 studies; 3,052 lesions; yield 70.5%) vs after 2012 (87 studies; 13,535 lesions; yield 69.2%) (P > .05). Additionally, there was no significant difference in yield when comparing different technologies. Studies with low risk of overall bias had a lower diagnostic yield than those with high risk of bias (66% vs 71%, respectively; P = .018). Lesion size > 2 cm, presence of bronchus sign, and reports with a high prevalence of malignancy in the study population were associated with significantly higher diagnostic yield. Significant (P < .0001) between-study heterogeneity was also noted.

INTERPRETATION

Despite the reported advances in bronchoscopic technology to diagnose PPLs, the diagnostic yield of guided bronchoscopy has not improved.

Comparison of electromagnetic navigation bronchoscopy and transthoracic needle biopsy for diagnosing bronchus sign-positive pulmonary lesions

OBJECTIVES

Electromagnetic navigation bronchoscopy (ENB) is an advanced technique for diagnosing peripheral pulmonary lesions, and the bronchus sign is a well-established factor for improving the diagnostic performance. However, ENB is a novel technology compared to the commonly adopted transthoracic needle biopsy (TTNB). There are limited data on the comparison of these techniques for diagnosing bronchus sign-positive lesions. Therefore, we aimed to compare the diagnostic yield and complication rates of ENB and TTNB for diagnosing lung cancer in bronchus sign-positive pulmonary lesions.

MATERIALS AND METHODS

We assessed 2,258 individuals who underwent either of the techniques for initial biopsy between September 2016 and May 2022 at a tertiary center in South Korea and analyzed 1,248 participants (153 ENB and 1,095 TTNB cases) with a positive bronchus sign. We performed multivariable logistic regression analyses to evaluate the factors associated with the diagnostic yield, sensitivity for malignancy, and procedure-related complications. In addition, the outcomes were compared between the two techniques after a 1:2 propensity score-matching to control for pre-procedural factors.

RESULTS

After adjustments for clinical/radiological factors, performing TTNB over ENB was not significantly associated with a higher diagnostic yield but with a higher risk of pneumothorax (OR = 9.69, 95% CI = 4.15-22.59). Propensity score-matching resulted in 459 participants (153 ENB and 306 TTNB cases) with balanced pre-procedural characteristics. The overall diagnostic yield did not differ significantly between ENB and TTNB (85.0% vs. 89.9%, p = 0.124). The diagnostic yield (86.7% vs. 90.3%, p = 0.280) and sensitivity for malignancy (85.3% vs. 88.8%, p = 0.361) were comparable among patients with a class 2 bronchus sign. However, TTNB demonstrated a significantly higher complication rate of pneumothorax (28.8% vs. 3.9%, p < 0.001) and pneumothorax requiring tube drainage (6.5% vs. 2.0%, p = 0.034) than ENB.

CONCLUSION

ENB demonstrated a diagnostic yield comparable with that of TTNB for diagnosing bronchus sign-positive peripheral pulmonary lesions with significantly lower complication rates.

Evaluation of electromagnetic navigational bronchoscopic biopsy of lung lesions performed by a thoracic surgical service

BACKGROUND

With the increasing use of computed tomography scans for lung cancer screening and surveillance of other cancers, thoracic surgeons are being referred patients with lung lesions for biopsies. Electromagnetic navigational bronchoscopy-guided lung biopsy is a relatively new technique for bronchoscopic biopsy. Our objective was to evaluate the diagnostic yields and safety of electromagnetic navigational bronchoscopy-guided lung biopsy.

METHODS

We conducted a retrospective review of patients who underwent an electromagnetic navigational bronchoscopy biopsy, performed by a thoracic surgical service, and evaluated its safety and diagnostic accuracy.

RESULTS

In total, 110 patients (men 46, women 64) underwent electromagnetic navigational bronchoscopy sampling of pulmonary lesions (n = 121; median size 27 mm; interquartile range 17-37 mm). There was no procedure-related mortality. Pneumothorax requiring pigtail drainage occurred in 4 patients (3.5%). Ninety-three (76.9%) of the lesions were malignant. Eighty-seven (71.9%) of the 121 lesions had an accurate diagnosis. Accuracy increased with increased lesion size (P = .0578) with a yield of 50% for lesions <2 cm, increasing to 81% for lesions ≥2 cm. The lesions that demonstrated a positive "bronchus sign" had a yield of 87% (45/52) compared with 61% (42/69) in lesions with a negative "bronchus sign" (P = .0359).

CONCLUSION

Thoracic surgeons can perform electromagnetic navigational bronchoscopy safely, with minimal morbidity and with good diagnostic yields. Accuracy increases with the presence of a bronchus sign and increasing lesion size. Patients with larger tumors and the bronchus sign may be candidates for this approach to biopsy. Further work is required to define the role of electromagnetic navigational bronchoscopy in the diagnosis of pulmonary lesions.

Learning Curve of Real-Time Imaging with C-Arm Based Tomography for Peripheral Lung Nodule Biopsy

The number of procedures required to attain proficiency with new bronchoscopic biopsy technologies for peripheral pulmonary lesions (PPLs) is uncertain. A prospective, single-center study evaluated learning curves of two operators performing PPL biopsies using a novel, real-time, intraoperative tomographic imaging system in consecutive procedures in adults with CT-detected PPLs. Operators were considered “proficient” when they asked three or fewer questions of the manufacturer’s clinical representative with no subsequent navigations in which they asked more than three questions. A total of 31 procedures were performed on 31 patients (Operator 1: 18, Operator 2: 13). Proficiency was achieved after an average of 10 procedures (Operator 1: 12, Operator 2: 8). From the learning curve to the post-learning curve period, the number of questions (median [IQR]: 23 [9.5–41.5] versus 0 [0–1], p < 0.001) and radiation dose (median [IQR]: 19.5 mGy/m2 [1.9–43.5] versus 1.5 mGy/m2 [0.7–3.3], p = 0.05) decreased significantly; procedure time decreased (median [IQR]: 12 min [7–20] versus 8 min [3–15], p = 0.29); and diagnostic yield increased significantly (13/20 cases [65%] to 11/11 cases [100%]), (p = 0.03). Based on this unique, clinically relevant method of assessing learning curve, proficiency with the Body Vision system was achieved at approximately the tenth procedure. These findings require validation in larger, diverse populations.

Safety and Feasibility of Photodynamic Therapy for Ablation of Peripheral Lung Tumors

BACKGROUND

Newer navigational bronchoscopy technologies render peripheral lung lesions accessible for biopsy and potential treatment. We investigated whether photodynamic therapy (PDT) delivered via navigational bronchoscopy is feasible and safe for ablation of peripheral lung tumors.

METHODS

Two studies evaluated PDT in patients with solid peripheral lung tumors followed by clinical follow-up (nonresection study, N=5) or lobectomy (resection study, N=10). Porfimer sodium injection was administered 40 to 50 hours before navigational bronchoscopy. Lesion location was confirmed by radial probe endobronchial ultrasonography. An optical fiber diffuser was placed within or adjacent to the tumor under fluoroscopic guidance; laser light (630 nm wavelength) was applied at 200 J/cm of diffuser length for 500 seconds. Tumor response was assessed by modified Response Evaluation Criteria in Solid Tumors at 3 and 6 months postprocedure (nonresection study) and pathologically (resection study).

RESULTS

There were no deaths, discontinuations for adverse events, or serious or grade ≥3 adverse events related to study treatments. Photosensitivity reactions occurred in 8 of 15 patients: 6 mild, 1 moderate, 1 severe (elevated porphyrins noted in blood after treatment). Among 5 patients with clinical follow-up, 1 had complete response, 3 had stable disease, and 1 had progressive disease at 6 months follow-up. Among 10 patients who underwent lobectomy, 1 had no evidence of tumor at resection (complete response), 3 had 40% to 50% tumor cell necrosis, 2 had 20% to 35%, and 4 had 5% to 10%.

CONCLUSION

PDT for nonthermal ablation of peripheral lung tumors was feasible and safe in this small study. Further study is warranted to evaluate efficacy and corroborate the safety profile.

When Pulmonologists Are Novice to Navigational Bronchoscopy, What Predicts Diagnostic Yield?

Predicting factors of diagnostic yield in electromagnetic navigation bronchoscopy (ENB) have been explored in a number of previous studies based on data from experienced operators. However, little is known about predicting factors when the procedure is carried out by operators in the beginning of their learning curve. We here aim to identify the role of operators' experience as well as lesion- and procedure characteristics on diagnostic yield of ENB procedures in the hands of novice ENB operators. Four operators from three centers without prior ENB experience were enrolled. The outcome of consecutive ENB procedures was assessed and classified as either diagnostic or non-diagnostic and predicting factors of diagnostic yield were assessed. A total of 215 procedures were assessed. A total of 122 (57%) of the ENB procedures resulted in diagnostic biopsies. Diagnostic ENB procedures were associated with a minor yet significant difference in tumor size compared to non-diagnostic/inconclusive ENB procedures (28 mm vs. 24 mm; p = 0.03). Diagnostic ENB procedures were associated with visible lesions at either fluoroscopy (p = 0.003) or radial endobronchial ultrasound (rEBUS), (p = 0.001). In the logistic regression model, lesion visibility on fluoroscopy, but none of operator experience, the presence of a bronchus sign, lesion size, or location nor visibility on rEBUS significantly impacted the diagnostic yield. In novice ENB operators, lesion visibility on fluoroscopy was the only factor found to increase the chance of obtaining a diagnostic sample.

The Feasibility of Using the "Artery Sign" for Pre-Procedural Planning in Navigational Bronchoscopy for Parenchymal Pulmonary Lesion Sampling

BACKGROUND

Electromagnetic navigation bronchoscopy (ENB) and robotic-assisted bronchoscopy (RAB) systems are used for pulmonary lesion sampling, and utilize a pre-procedural CT scan where an airway, or "bronchus sign", is used to map a pathway to the target lesion. However, up to 40% of pre-procedural CT's lack a "bronchus sign" partially due to surrounding emphysema or limitation in CT resolution. Recognizing that the branches of the pulmonary artery, lymphatics, and airways are often present together as the bronchovascular bundle, we postulate that a branch of the pulmonary artery ("artery sign") could be used for pathway mapping during navigation bronchoscopy when a "bronchus sign" is absent. Herein we describe the navigation success and safety of using the "artery sign" to create a pathway for pulmonary lesion sampling.

METHODS

We reviewed data on consecutive cases in which the "artery sign" was used for pre-procedural planning for conventional ENB (superDimension™, Medtronic) and RAB (Monarch™, Johnson & Johnson). Patients who underwent these procedures from July 2020 until July 2021 at the University of Minnesota Medical Center and from June 2018 until December 2019 at the University of Chicago Medical Center were included in this analysis (IRB #19-0011 for the University of Chicago and IRB #00013135 for the University of Minnesota). The primary outcome was navigation success, defined as successfully maneuvering the bronchoscope to the target lesion based on feedback from the navigation system. Secondary outcomes included navigation success based on radial EBUS imaging, pneumothorax, and bleeding rates.

RESULTS

A total of 30 patients were enrolled in this analysis. The median diameter of the lesions was 17 mm. The median distance of the lesion from the pleura was 5 mm. Eleven lesions were solid, 15 were pure ground glass, and 4 were mixed. All cases were planned successfully using the "artery sign" on either the superDimension™ ENB (n = 15) or the Monarch™ RAB (n = 15). Navigation to the target was successful for 29 lesions (96.7%) based on feedback from the navigation system (virtual target). Radial EBUS image was acquired in 27 cases (90%) [eccentric view in 13 (43.33%) and concentric view in 14 patients (46.66%)], while in 3 cases (10%) no r-EBUS view was obtained. Pneumothorax occurred in one case (3%). Significant airway bleeding was reported in one case (3%).

CONCLUSIONS

We describe the concept of using the "artery sign" as an alternative for planning EMN and RAB procedures when "bronchus sign" is absent. The navigation success based on virtual target or r-EBUS imaging is high and safety of sampling of such lesions compares favorably with prior reports. Prospective studies are needed to assess the impact of the "artery sign" on diagnostic yield.

Does the Addition of Radial Endobronchial Ultrasound Improve the Diagnostic Yield of Electromagnetic Navigation Bronchoscopy? A Systematic Review

BACKGROUND

Lung cancer is the leading cause of cancer-related death worldwide. Early diagnosis is crucial to increased survival rates. Radial endobronchial ultrasound (rEBUS) and electromagnetic navigation bronchoscopy (ENB) have been developed for the diagnosis of small lung lesions. The aim of this systematic review was to evaluate whether the combination of rEBUS and ENB is superior to ENB alone.

METHOD

A systematic search was performed using MEDLINE, Embase, and Cochrane Library databases on "ENB," and conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The project was registered with PROSPERO, number CRD42020214682.

RESULTS

In total, 2,092 studies were identified through a literature search. Five studies were included in the final review. One study found that the addition of rEBUS increased diagnostic yield, while another concluded the converse. Three studies did not have significant results. Meta-analysis was not feasible due to heterogeneity and the small number of studies.

CONCLUSION

As the current evidence on the topic is sparse and heterogeneous, it is not possible to conclude whether the addition of rEBUS to ENB has a significant impact on diagnostic yield. Further studies are needed to illuminate this question in order to ensure optimal choice of endoscopic technique as well as used time and resources. The project received funding from the Region of Southern Denmark's PhD fund.

Optimizing Diagnostic and Staging Pathways for Suspected Lung Cancer: A Decision Analysis

BACKGROUND

The optimal diagnostic and staging strategy for patients with suspected lung cancer is not known.

RESEARCH QUESTION

What diagnostic and staging strategies are most cost-effective for lung cancer?

STUDY DESIGN AND METHODS

A decision model was developed by using a hypothetical patient with a high probability of lung cancer. Sixteen unique permutations of bronchoscopy with fluoroscopy, radial endobronchial ultrasound, electromagnetic navigation, convex endobronchial ultrasound with or without rapid-onsite evaluation (ROSE), CT-guided biopsy (CTBx), and surgery were evaluated. Outcomes included cost, complications, mortality, time to complete the evaluation, rate of undetected N2-3 disease at surgery, incremental cost-complication ratio, and willingness-to-pay thresholds. Sensitivity analyses were performed on primary outcomes.

RESULTS

For a peripheral lung lesion and radiographic N0 disease, the best bronchoscopy strategy costs $1,694 more than the best CTBx strategy but resulted in fewer complications (risk difference, 14%). The additional cost of bronchoscopy to avoid one complication from a CTBx strategy was $12,037. The cost and cumulative complications of bronchoscopy strategies increased compared with CTBx strategies for small lesions. The cost and cumulative complications of bronchoscopy strategies decreased compared with CTBx strategies when a bronchus sign was present, but bronchoscopy remained more costly overall. For a central lesion and/or radiographic N1-3 disease, convex endobronchial ultrasound with ROSE followed by lung biopsy with incremental cost-effectiveness ratio, if required, was more cost-effective than any CTBx strategy across all outcomes. Strategies with ROSE were always more cost-effective than those without, irrespective of scenario. Trade-offs also exist between different bronchoscopy strategies, and optimal choices depend on the value placed on individual outcomes and willingness-to-pay.

INTERPRETATION

The most cost-effective strategies depend on nodal stage, lesion location, type of peripheral bronchoscopic biopsy, and the use of ROSE. For most clinical scenarios, many strategies can be eliminated, and trade-offs between the remaining competitive strategies can be quantified.

Lesion characteristics affecting yield of electromagnetic navigational bronchoscopy

RATIONALE

Electromagnetic navigational bronchoscopy (ENB) is an important, minimally invasive diagnostic tool for malignant and benign peripheral lung lesions, offering lower complication risks than transthoracic needle aspirations. As a relatively new technology, the best sampling modality and lesion characteristics for ENB has yet to be determined. We evaluated the sensitivity and diagnostic yield of different sampling modalities (needle aspiration, brush biopsy, transbronchial forceps biopsies) and radiographical lesion characteristics by Tsuboi classification. We also evaluated the difference in yield and sensitivity with the addition of radial probe EBUS to augment ENB.

METHODS

We completed a retrospective chart review of all patients that had ENB performed at our institution since its implementation in 2011. We reviewed the lesion size, location, Tsuboi classification, cytology, pathology results and analyzed biopsy specimen tool types.

RESULTS

We included a total of 248 patients who had ENB performed between 2011 and 2018. Average age was 67 years and 50% female. A total of 270 lesions were targeted with a mean size of 24 ± 12 mm. Sensitivity for malignancy was 59.2% with a diagnostic yield of 72.3%. Sensitivity and diagnostic accuracy trended higher with combined sampling modalities (brush and transbronchial needle aspiration and forcep biopsy). Lesions with type I and type II Tsuboi classification of bronchus sign had higher sensitivity compared to type III classification (67.9% [n = 101 type I], 64.6% [n = 65 type II], 37.9% [n = 36 type III]), p = 0.01 and p = 0.04.

CONCLUSION

For navigation bronchoscopy, sensitivity is higher in bronchus sign lesions that end directly into lesion (Tsuboi type I) and travel through malignant lesions (Tsuboi type II) compared to tangentially circumventing the lesion (Tsuboi type III).

The Diagnostic Accuracy and Sensitivity for Malignancy of Radial-Endobronchial Ultrasound and Electromagnetic Navigation Bronchoscopy for Sampling of Peripheral Pulmonary Lesions: Systematic Review and Meta-analysis

BACKGROUND

Lung cancer screening with computed tomography chest is identifying peripheral pulmonary lesions (PPLs) suspicious for early-stage lung cancer at increasing rates. Radial-endobronchial ultrasound (R-EBUS) and electromagnetic navigation bronchoscopy (ENB) are 2 methods to sample PPLs to diagnose and treat early lung cancer. ENB has a higher operating financial cost, however, the rationale for its use is possible higher diagnostic accuracy versus R-EBUS.

OBJECTIVE

The objective of this study was to determine the comparative diagnostic accuracy, sensitivity, and negative predictive value for R-EBUS and ENB in sampling PPLs.

METHODS

A systematic review and meta-analysis were conducted. The Ovid Medline database was queried for original research reporting a diagnostic yield of R-EBUS or ENB for PPLs identified on computed tomography chest suspicious for malignancy. The I statistic assessed study heterogeneity. Random effects models produced pooled estimates of diagnostic accuracy and sensitivity for malignancy. Reasons for heterogeneity were explored with meta-regression. Publication bias and small study effects were assessed.

RESULTS

A total of 41 studies involved 2988 lung nodules (R-EBUS 2102, ENB 886) in 3204 patients (R-EBUS 2097, ENB 1107). Overall sensitivity to detect cancer was 70.7% [95% confidence interval (CI): 67.2-74.0]; R-EBUS 70.5% (95% CI: 66.1-74.8), ENB 70.7% (95% CI: 64.7-76.8). Pooled overall diagnostic accuracy was 74.2% (95% CI: 71.0-77.3); R-EBUS 72.4% (95% CI: 68.7-76.1), ENB 76.4% (95% CI: 70.8-82.0). The localization modalities had comparative safety profiles of <2% complications.

CONCLUSION

Both technologies have a high proportion of successful PPL localization with similar sensitivity for malignancy and accuracy. As such, both reasonable options for health care authorities to employ diagnostic algorithms.

Jet Ventilation Decreases Target Motion and Increases Yield of ENB Especially in Lesions With Negative Bronchus Sign

BACKGROUND

Electromagnetic navigational bronchoscopy (ENB) is used to obtain peripheral lung tissue samples for evaluation and staging of central and peripheral lung lesions. Jet ventilation delivers and maintains a sustained airway pressure at high frequency, chest wall and diaphragmatic movement is drastically reduced compared with traditional ventilation. The current study looks to examine the effectiveness of tissue sampling (diagnostic yield) while using jet ventilation on target-lesion movement when compared with traditional ventilation.

METHODS

A total of 36 patients received total intravenous anesthesia with both jet and traditional ventilation during ENB procedure where sensor to lesion displacement was recorded. When planning the ENB procedure, the presence or absence of a viable airway to the lesion was recorded. Sensor to lesion movement was recorded and compared for significance using χ and t tests, utilizing stringent P-values.

RESULTS

Overall patients with an airway to the lesion (n=23) had a higher proportion of successful diagnostic biopsies, 83% compared with those patients that lacked an airway to the lesion (n=13) 70% proportion of successful diagnostic biopsies. When using jet ventilation, the chance of nonzero displacement was 8.3% (0.14 mm), regardless of the presence of an airway. Compared with traditional ventilation, the chance of a nonzero displacement between the sensor and target-lesion was 83% (6.4 mm), independent of airway presence to the lesions.

CONCLUSION

In patients without an airway, jet ventilation significantly decreased target displacement when compared with traditional ventilation (2 vs. 17 mm). In patients with direct airway to the lesion, jet ventilation did not significantly decrease target displacement when compared with the traditional approach.

[Clinical Application of Electromagnetic Navigation Bronchoscopy on the Diagnosis of Peripheral Lung Lesions]

背景与目的

电磁导航支气管镜是一种能够进行肺部病变精准定位的工具，在肺部病变诊断中具有重要价值，但由于价格昂贵，在我国应用尚未普及，急需总结其在临床中的应用，尤其是肺部结节诊断中的经验。

方法

回顾性分析我科2017年7月-2018年12月诊断为肺外周病变，且行电磁导航支气管镜检查患者的临床资料，总结其应用经验。

结果

18例患者（男性10例，女性8例），共21处病变，11例诊断明确，8例诊断为肺腺癌，1例诊断为肺结核，2例诊断为小细胞肺癌，诊断阳性率为61.1%，敏感性为73.3%，诊断阳性率与病变大小相关， > 2 cm病变诊断阳性率为100.0%（P=0.04）。

结论

电磁导航支气管镜在临床中安全有效，对于病变 > 2 cm的肺外周病变诊断阳性率较高，有着广阔的临床应用前景。

Slow-growing metastatic adenocarcinoma diagnosed via electro-navigational bronchoscopy

Here, we describe the case of a 67-year-old man who had been under surveillance for solitary pulmonary nodule for two years and was diagnosed with malignancy via electro-navigational bronchoscopy (ENB). Surveillance computed tomography scan of the thorax showed annual growth increments of the pulmonary nodule. In view of his Brock score showing a 35% probability of malignancy, the patient was subjected to ENB, and metastatic adenocarcinoma from the gastrointestinal tract was diagnosed. ENB was done using a machine on loan from Veran Medical Technologies. The procedure was successful, with no immediate or long-term complications. The diagnosis following histopathological examination was adenocarcinoma, and he was subsequently referred to our oncology unit for further management.

Sensitivity and Safety of Electromagnetic Navigation Bronchoscopy for Lung Cancer Diagnosis: Systematic Review and Meta-analysis

BACKGROUND

Bronchoscopy is a useful tool for the diagnosis of lesions near central airways; however, the diagnostic accuracy of these procedures for peripheral pulmonary lesions (PPLs) is a matter of ongoing debate. In this setting, electromagnetic navigation bronchoscopy (ENB) is a technique used to navigate and obtain samples from these lesions. This systematic review and meta-analysis aims to explore the sensitivity of ENB in patients with PPLs suspected of lung cancer.

RESEARCH QUESTION

In patients with peripheral pulmonary lesion suspected of lung cancer, what is the sensitivity and safety of electromagnetic navigation bronchoscopy compared to surgery or longitudinal follow up?

STUDY DESIGN AND METHODS

A comprehensive search of several databases was performed. Extracted data included sensitivity of ENB for malignancy, adequacy of the tissue sample, and complications. The study quality was assessed using the QUADAS-2 tool, and the combined data were meta-analyzed using a bivariate method model. A summary receiver operatic characteristic curve (sROC) was created. Finally, the quality of evidence was rated using the Grading of Recommendations Assessment, Development and Evaluation approach.

RESULTS

Forty studies with a total of 3,342 participants were included in our analysis. ENB reported a pooled sensitivity of 77% (95% CI, 72%-82%; I² = 80.6%) and a specificity of 100% (95% CI, 99%-100%; I² = 0%) for malignancy. The sROC showed an area under the curve of 0.955 (P = .03). ENB achieved a sufficient sample for ancillary tests in 90.9% (95% CI, 84.8%-96.9%; I² = 80.7%). Risk of pneumothorax was 2.0% (95% CI, 1.0-3.0; I² = 45.2%). We found subgroup differences according to the risk of bias and the number of sampling techniques. Meta-regression showed an association between sensitivity and the mean distance of the sensor tip to the center of the nodule, the number of tissue sampling techniques, and the cancer prevalence in the study.

INTERPRETATION

ENB is very safe with good sensitivity for diagnosing malignancy in patients with PPLs. The applicability of our findings is limited because most studies were done with the superDimension navigation system and heterogeneity was high.

TRIAL REGISTRY

PROSPERO; No.: CRD42019109449; URL: https://www.crd.york.ac.uk/prospero/.

Electromagnetic navigation bronchoscopy for lung nodule evaluation. Patient selection, diagnostic variables and safety

BACKGROUND

Electromagnetic navigation bronchoscopy (ENB) is a relatively new technique to diagnose pulmonary lesions in patients with reduced lung function. Several parameters have been shown to affect diagnostic yield including patient selection. We performed a prospective registration of data on one hundred patients who consecutively underwent electromagnetic navigation bronchoscopy. Selection criteria, patient characteristics, lesion size, distance to pleura, location of the lesion and presence of bronchus sign on computed tomography were registered.

METHODS

Navigation was performed using the superDimension hardware and software system. Patients were referred to ENB from a multidisciplinary team conference. We did not use fluoroscopy, endobronchial ultrasound equipment, rapid onsite evaluation or general anesthesia during the procedure. All patients in whom no malignant diagnose was found were subsequently followed for two years in order to verify a benign nature of the pulmonary lesion.

RESULTS

One hundred and nine ENB procedures were performed between September 2009 and November 2014. Overall diagnostic yield was 68%. Twenty seven of 49 malignant tumors were found by ENB leading to a sensitivity for malignancy of 55%. The sensitivity for malignancy was significantly higher for lesions in the upper and middle lobes compared to the lower lobes (P = 0.01). Lesions size, distance to pleura and presence of bronchus sign did not affect sensitivity.

CONCLUSION

ENB is a safe diagnostic procedure in an everyday setting with an acceptable diagnostic yield even without addition of supportive diagnostic methods and offers a possibility to diagnose pulmonary nodules in patients for whom other diagnostic procedures are too hazardous or have proven unsuccessful.

Computed Tomography Bronchus Sign and the Diagnostic Yield of Guided Bronchoscopy for Peripheral Pulmonary Lesions. A Systematic Review and Meta-Analysis

RATIONALE

Indeterminate peripheral pulmonary lesions (PPLs) often require tissue diagnosis. If nonsurgical biopsy techniques are considered, deciding between bronchoscopic transbronchial versus computed tomography-guided transthoracic biopsy can be difficult. The former has a low diagnostic yield with a low complication risk, whereas the latter has a better diagnostic yield but a higher complication rate. Investigators have looked at various lesion characteristics that can predict the diagnostic yield of guided bronchoscopic biopsies. Although consensus exists that larger size and proximity to the hilum increase the diagnostic yield, there is ongoing debate about the association between computed tomography bronchus sign (air-filled bronchus in close proximity of the lesion as seen on computed tomography imaging) and the diagnostic yield of guided bronchoscopic modalities.

OBJECTIVES

To perform a meta-analysis and systematic review, determining the association between computed tomography bronchus sign and the diagnostic yield of guided bronchoscopy for PPLs.

METHODS

MEDLINE, Embase, Scopus, and Google Scholar were searched in January 2018 for guided bronchoscopy studies that had assessed the impact of computed tomography bronchus sign on the diagnostic yield. The quality of included studies was assessed using Quality Assessment of Diagnostic Accuracy Studies-2 tool. Meta-analysis was performed using MedCalc (version 18). Odds ratios were used to compare yield of lesions with and without bronchus sign. Random effects model was used when significant heterogeneity was observed (I² > 40%).

RESULTS

For 2,199 lesions with computed tomography bronchus sign, the overall weighted diagnostic yield was 74.1% (95% confidence interval, 68.3-79.5%). For 971 lesions without computed tomography bronchus sign, the overall weighted diagnostic yield was 49.6% (95% confidence interval, 39.6-59.5%). The odds ratio for successfully diagnosing a lesion with computed tomography bronchus sign was 3.4 (95% confidence interval, 2.4-5.0). Possible sources of heterogeneity in the meta-analysis included differences in study designs, guidance modalities, and cancer prevalence. The odds ratio for successfully diagnosing a lesion with computed tomography bronchus sign was relatively lower for prospective studies.

CONCLUSIONS

PPLs with computed tomography bronchus sign are more likely to be diagnosed with guided bronchoscopy than the lesions without computed tomography bronchus sign. Clinicians should consider this, along with the lesion size and distance from the hilum, when contemplating guided bronchoscopy for PPLs.

Navigation Bronchoscopy

With the advent of lung cancer screening, and the increasingly frequent use of computed tomography (CT) scanning for investigating non-pulmonary pathology (for example CT coronary angiogram), the number of pulmonary nodules requiring further investigation has risen significantly. Most of these nodules are found in the lung periphery, which presents challenges to biopsy, and many centers rely on trans-thoracic needle biopsy performed under image guidance by radiologists. However, the desire to minimize complications is driving the development of increasingly accurate navigation bronchoscopy platforms, something that will be crucial in the new era of bronchoscopic therapeutics for lung cancer. This review describes these platforms, summarizes the current evidence for their use, and takes a look at future developments.

Cone-Beam CT With Augmented Fluoroscopy Combined With Electromagnetic Navigation Bronchoscopy for Biopsy of Pulmonary Nodules

BACKGROUND

Electromagnetic navigation bronchoscopy (ENB) has been widely adopted as a guidance technique for biopsy of peripheral lung nodules. However, ENB is limited by the lack of real-time confirmation of the biopsy devices. Intraprocedural cone-beam computed tomography (CBCT) imaging can be utilized to assess or confirm the location of biopsy devices. The aim of this study is to determine the safety and diagnostic yield (DY) of image fusion of intraprocedural CBCT data with live fluoroscopy (augmented fluoroscopy) during ENB-guided biopsy of peripheral lung nodules.

METHODS

Data from 75 consecutive patients who underwent biopsy with ENB was collected retrospectively. Patients underwent CBCT imaging while temporarily suspending mechanical ventilation. CBCT data were acquired and 3-dimensional segmentation of nodules was performed using commercially available software (OncoSuite). During ENB, the segmented lesions were projected and fused with live fluoroscopy enabling real-time 3-dimensional guidance.

RESULTS

A total of 93 lesions with a median size of 16.0 mm were biopsied in 75 consecutive patients. The overall DY by lesion was 83.7% (95% confidence interval, 74.8%-89.9%). Multivariate regression analysis showed no independent correlation between lesion size, lesion location, lesion visibility under standard fluoroscopy, and the presence of a bronchus sign with DY. Pneumothorax occurred in 3 patients (4%).

CONCLUSION

Intraprocedural CBCT imaging with augmented fluoroscopy is feasible and effective and is associated with high DY during ENB-guided biopsies.

Clinical updates of approaches for biopsy of pulmonary lesions based on systematic review

BACKGROUND

Convenient approaches for accurate biopsy are extremely important to the diagnosis of lung cancer. We aimed to systematically review the clinical updates and development trends of approaches for biopsy, i.e., CT-guided PTNB (Percutaneous Transthoracic Needle Biopsy), ENB (Electromagnetic Navigation Bronchoscopy), EBUS-TBNA (Endobroncheal Ultrasonography-Transbronchial Needle Aspiration), mediastinoscopy and CTC (Circulating Tumor Cell).

METHODS

Medline and manual searches were performed. We identified the relevant studies, assessed study eligibility, evaluated methodological quality, and summarized diagnostic yields and complications regarding CT-guided PTNB (22 citations), ENB(31 citations), EBUS-TBNA(66 citations), Mediastinoscopy(15 citations) and CTC (19 citations), respectively.

RESULTS

The overall sensitivity and specificity of CT-guided PTNB were reported to be 92.52% ± 3.14% and 97.98% ± 3.28%, respectively. The top two complications of CT-guided PTNB was pneumothorax (946/4170:22.69%) and hemorrhage (138/1949:7.08%). The detection rate of lung cancer by ENB increased gradually to 79.79% ± 15.34% with pneumothorax as the top one complication (86/1648:5.2%). Detection rate of EBUS-TBNA was 86.06% ± 9.70% with the top three complications, i.e., hemorrhage (53/8662:0.61%), pneumothorax (46/12432:0.37%) and infection (34/11250:0.30%). The detection rate of mediastinoscopy gradually increased to 92.77% ± 3.99% with .hoarseness as the refractory complication (4/2137:0.19%). Sensitivity and specificity of CTCs detection by using PCR (Polymerase Chain Reaction) were reported to be 78.81% ± 14.72% and 90.88% ± 0.53%, respectively.

CONCLUSION

The biopsy approaches should be chosen considering a variety of location and situation of lesions. CT-guided PTNB is effective to reach lung parenchyma, however, diagnostic accuracy and incidence of complications may be impacted by lesion size or needle path length. ENB has an advantage for biopsy of smaller and deeper lesions in lung parenchyma. ENB plus EBUS imaging can further improve the detection rate of lesion in lung parenchyma. EBUS-TBNA is relatively safer and mediastinoscopy provides more tissue acquisition and better diagnostic yield of 4R and 7th lymph node. CTC detection can be considered for adjuvant diagnosis.

Electromagnetic navigation bronchoscopy-Chungnam National University Hospital experience

Background

To find small pulmonary nodules or ground grass nodules (GGNs) with video-assisted thoracoscopic surgery (VATS) is very difficult. There are several conventional methods to localize small nodules or GGNs, which require additional radiation exposure and may cause some complications such as pneumothorax or hemothorax. We aimed to evaluate the effectiveness and feasibility of electromagnetic navigational bronchoscopy-guided pulmonary localization in a minimally invasive thoracic surgery field.

Methods

We retrospectively reviewed the medical records from a prospectively collected database of the patients who underwent ENB procedure for biopsy and/or localization of pulmonary resection at the Chungnam National University Hospital from January 2017 to January 2018.

Results

A total of 37 ENB-guided dye-markings or biopsies for 37 lesions in 30 patients were performed. Thirty-two ENB-guided localizations using dye-marking for resection were performed in 25 patients. The median nodule size was 9 mm (IQR: 7-13 mm), and the median distance from the pleura was 6 mm (IQR: 3-10 mm). The failure of an ENB-guided localization was noted in 4 cases (12.5%). There was no major complication noted with the procedure, and just two patients showed mild intrabronchial bleeding stopped spontaneously. The most common lobar location was right lower lobe (11 cases, 34.4%), and all cases of localization failure were right lower lobe. A pathologic diagnosis was obtained from surgically resected specimen (not from ENB biopsy: 32 of 32 localizations, 100%), neoplastic lesions were 23 cases (72%). Of them, a primary lung cancer and metastatic lung cancer were noted in 11 cases, and in 11cases, respectively. All margins of the nodules were negative.

Conclusions

The ENB-guided dye localization by a well-trained thoracic surgeon enables accurate intraoperative identification of GGN or a small pulmonary nodule, with minimal complications and enables minimally invasive surgery including single port surgery.

Interventional bronchoscopy in adults

INTRODUCTION

The field of interventional pulmonology (IP) is a rapidly maturing subspecialty of pulmonary medicine, which emphasizes advanced diagnostic and therapeutic bronchoscopy for the evaluation and management of central airway obstruction, mediastinal/hilar adenopathy and lung nodules/masses, as well as minimally invasive diagnostic and therapeutic pleural procedures. Areas covered: This review describes advances in diagnostic and therapeutic bronchoscopic techniques. Expert commentary: In the past decade, there has been a remarkable growth in available technology and equipment, as well as clinical and translational research efforts focused on patient-centered outcomes. Furthermore, the recent establishment of a uniform accreditation standard for all IP fellowship programs in the United States was an important step in the continued evolution of this subspecialty of pulmonary medicine.

Advanced bronchoscopic techniques for the diagnosis of peripheral pulmonary lesions

PURPOSE OF REVIEW

The review describes recent advances in bronchoscopic modalities used to diagnose peripheral pulmonary lesions.

RECENT FINDINGS

The pooled diagnostic yield and sensitivity of radial probe endobronchial ultrasound (r-EBUS) has been reported to be 56% for lesions less than 2 cm and 78% for lesions more than 2 cm and 73%, respectively. The pooled diagnostic yield and sensitivity of electromagnetic navigational bronchoscopy (ENB) has been reported to be 65 and 71%, respectively. However, significant heterogeneity between studies was evident for both r-EBUS and ENB (sensitivity of r-EBUS: I = 75%; sensitivity of ENB: I = 57% and diagnostic yield of ENB: I = 66%). Recent studies show that these technologies do not perform in the clinical setting as well as reported in the literature. Conceptually, the domains of advanced bronchoscopic modalities that affect performance are navigation, maneuverability, and location verification. Combining technologies that deal with different domains, such as ENB (navigation) and r-EBUS (location verification), has led to synergistic effects with improved outcomes.

SUMMARY

The performance characteristics of the different advanced bronchoscopic modalities reported in the literature may not be representative of performance in clinical practice because of clinical and statistical heterogeneity in the published literature. However, evidence is accumulating that synergistic combinations of technologies may ultimately lead to better performance.

The introduction of electromagnetic navigation bronchoscopy for the diagnosis of small pulmonary peripheral lesions in an Asian population

Background

Electromagnetic navigation bronchoscopy (ENB) is emerging as a useful new technique for diagnosing small pulmonary peripheral lesions (SPPLs). However, the accuracy and efficiency of ENB have not been investigated in Asian populations where the differential diagnoses for SPPLs may be different. To analyze this question, this study included patients who received diagnostic ENB followed by surgery for the excision of SPPLs.

Methods

Consecutive patients referred to the Department of Thoracic Surgery, Shanghai Pulmonary Hospital (Tongji University), between May 2014 and April 2015 were recruited. ENB was used to obtain biopsy tissue and make a diagnosis, which was then confirmed by histopathological examination.

Results

The ENB was performed on 84 SPPLs of 78 patients in the study, with four patients having more than one SPPL. It successfully reached and biopsied 81 lesions. The average ENB navigation time was 10.8 minutes (range, 0.5-52 minutes). No mortality occurred, with only two complications (one bleeding and one pneumothorax). The mean diameter of the biopsied SPPLs was 19.0 mm (range, 5.0-30.0 mm). The distance from the sensor probe to the focus was 8.0 mm (range, 1-16 mm). ENB diagnosis had identical results with histopathology examination in 81 lesions (37 lung cancer and 41 non-lung cancer). The sensitivity of ENB was 92.9% (78 out of 84 lesions) in this study.

Conclusions

These data suggested that ENB was an accurate and efficient procedure to sample and diagnose SPPLs in the Asian population. It appeared that ENB had a high percentage of successful results in both navigating and aiding in the diagnosis of SPPLs in the Asian population.

Diagnostic Yield of Electromagnetic Navigation Bronchoscopy Using a Curved-tip Catheter to Aid in the Diagnosis of Pulmonary Lesions

BACKGROUND

Electromagnetic navigation bronchoscopy (ENB) may aid in the diagnosis of solitary pulmonary lesions with a lower complication rate than conventional diagnostic modalities. A curved-tip catheter is now available for use with ENB; however, the diagnostic yield of this device has not been previously reported.

METHODS

A single-center, single-operator retrospective chart review was performed on patients who underwent ENB for the diagnosis of pulmonary lesions. A curved-tip catheter was used in all procedures; angle options were chosen depending on lesion location. After navigation to the target lesion, fine-needle aspiration, brushings, biopsies, and bronchoalveolar lavage were performed in all patients. Correct localization was confirmed with fluoroscopy.

RESULTS

Thirty-one consecutive patients underwent ENB between February and October 2014. The mean lesion size was 1.8 cm (range, 0.4 to 4.0 cm) and 35% were in the right upper lobe. The probe tip was navigated to the target lesion in all cases. A diagnosis was obtained in 30/31 patients (96.8%). Twenty-two (71%) had a definitive histologic diagnosis of malignancy. One case was nondiagnostic requiring a repeat fine-needle aspiration. The remaining 8 nonmalignant cases were followed radiologically and demonstrated no progression of lesion size through at least 1 year. Fiducials were placed in 48% of cases. There were 2 pneumothoraces (6.5%), one of which required chest tube placement (3.2%).

CONCLUSIONS

This study suggests that the curved-tip catheter is a useful modality for diagnosing peripheral pulmonary lesions with ENB. The diagnostic yield of ENB using this catheter was superior to that reported in other studies utilizing straight catheters.

Improved targeting accuracy of lung tumor biopsies with scanning-beam digital x-ray tomosynthesis image guidance

PURPOSE

Electromagnetic navigation bronchoscopy (ENB) provides improved targeting accuracy during transbronchial biopsies of suspicious nodules. The greatest weakness of ENB-based guidance is the registration divergence that exists between the planning CT, acquired days or weeks before the intervention, and the patient on the table on the day of the intervention. Augmenting ENB guidance with real-time tomosynthesis imaging during the intervention could mitigate the divergence and further improve the yield of ENB-guided transbronchial biopsies. The real-time tomosynthesis prototype, the scanning-beam digital x-ray (SBDX) system, does not currently display images reconstructed by the iterative algorithm that was developed for this lung imaging application. A protocol using fiducial markers was therefore implemented to permit evaluation of potential improvements that would be provided by the SBDX system in a clinical setting.

METHODS

Ten 7 mm lesions (5 per side) were injected into the periphery of each of four preserved pig lungs. The lungs were then placed in a vacuum chamber that permitted simulation of realistic motion and deformation due to breathing. Standard clinical CT scans of the pig lung phantoms were acquired and reconstructed with isotropic resolution of 0.625 mm. Standard ENB-guided biopsy procedures including target identification, path planning, CT-to-lung registration and navigation to the lesion were carried out, and a fiducial marker was placed at the location at which a biopsy would have been acquired. The channel-to-target distance provided by the ENB system prior to fiducial placement was noted. The lung phantoms were then imaged using the SBDX system, and using high-resolution conebeam CT. The distance between the fiducial marker tip and the lesion was measured in SBDX images and in the gold-standard conebeam-CT images. The channel-to-target divergence predicted by the ENB system and measured in the SBDX images was compared to the gold standard to determine if improved targeting accuracy could be achieved using SBDX image guidance.

RESULTS

As expected, the ENB system showed poorer targeting accuracy for small peripheral nodules. Only 20 nodules of the 40 injected could be adequately reached using ENB guidance alone. The SBDX system was capable of visualizing these small lesions, and measured fiducial-to-target distances on SBDX agreed well with measurements in gold-standard conebeam-CT images (p = 0.0001). The correlation between gold-standard conebeam-CT distances and predicted fiducial-to-target distances provided by the ENB system was poor (p = 0.72), primarily due to inaccurate ENB CT-to-body registration and movement due to breathing.

CONCLUSIONS

The SBDX system permits visualization of small lung nodules, as well as accurate measurement of channel-to-target distances. Combined use of ENB with SBDX real-time image guidance could improve accuracy and yield of biopsies, particularly of those lesions located in the periphery of the lung.

Navigation bronchoscopy for diagnosis and small nodule location

Lung cancer continues to be the most common cause of cancer death. Screening programs for high risk patients with the use of low-dose computed tomography (CT) has led to the identification of small lung lesions that were difficult to identify using previous imaging modalities. Electromagnetic navigational bronchoscopy (ENB) is a novel technique that has shown to be of great utility during the evaluation of small, peripheral lesions, that would otherwise be challenging to evaluate with conventional bronchoscopy. The diagnostic yield of navigational bronchoscopy however is highly variable, with reports ranging from 59% to 94%. This variability suggests that well-defined selection criteria and standardized protocols for the use of ENB are lacking. Despite this variability, we believe that this technique is a useful tool evaluating small peripheral lung lesions when patients are properly selected.

Electromagnetic navigation bronchoscopy: clinical utility in the diagnosis of lung cancer

Electromagnetic navigation bronchoscopy (ENB) is one of several technological advances which have broadened the indications for bronchoscopy in the diagnostic workup of lung cancer. The technique facilitates bronchoscopic sampling of peripheral pulmonary nodules as well as mediastinal lymph nodes, although wide availability and expertise in endobronchial ultrasonography has limited its application in routine clinical practice to the former. ENB in this setting is quite versatile and may be considered an established alternative to more invasive techniques, especially in selected patients with underlying pulmonary disease or comorbidities at high risk for complications from computer topography-guided fine needle aspiration or surgical resection. Nodule sampling may be performed with a variety of instruments, including forceps, cytology brushes, and transbronchial needles. Although samples are generally small, they are often suitable for molecular analysis.

Design of a prospective, multicenter, global, cohort study of electromagnetic navigation bronchoscopy

Background

Electromagnetic navigation bronchoscopy (ENB) procedures allow physicians to access peripheral lung lesions beyond the reach of conventional bronchoscopy. However, published research is primarily limited to small, single-center studies using previous-generation ENB software. The impact of user experience, patient factors, and lesion/procedural characteristics remains largely unexplored in a large, multicenter study.

Methods/Design

NAVIGATE (Clinical Evaluation of superDimension™ Navigation System for Electromagnetic Navigation Bronchoscopy) is a prospective, multicenter, global, cohort study. The study aims to enroll up to 2,500 consecutive subjects presenting for evaluation of lung lesions utilizing the ENB procedure at up to 75 clinical sites in the United States, Europe, and Asia. Subjects will be assessed at baseline, at the time of procedure, and at 1, 12, and 24 months post-procedure. The pre-test probability of malignancy will be determined for peripheral lung nodules. Endpoints include procedure-related adverse events, including pneumothorax, bronchopulmonary hemorrhage, and respiratory failure, as well as quality of life, and subject satisfaction. Diagnostic yield and accuracy, repeat biopsy rate, tissue adequacy for genetic testing, and stage at diagnosis will be reported for biopsy procedures. Complementary technologies, such as fluoroscopy and endobronchial ultrasound, will be explored. Success rates of fiducial marker placement, dye marking, and lymph node biopsies will be captured when applicable. Subgroup analyses based on geography, demographics, investigator experience, and lesion and procedure characteristics are planned.

Discussion

Study enrollment began in April 2015. As of February 19, 2016, 500 subjects had been enrolled at 23 clinical sites with enrollment ongoing. NAVIGATE will be the largest prospective, multicenter clinical study on ENB procedures to date and will provide real-world experience data on the utility of the ENB procedure in a broad range of clinical scenarios.

Trial registration

ClinicalTrials.gov NCT02410837. Registered 31 March 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-016-0228-y) contains supplementary material, which is available to authorized users.

Navigational Bronchoscopy for Early Lung Cancer: A Road to Therapy

Peripheral lung nodules remain challenging for accurate localization and diagnosis. Once identified, there are many strategies for diagnosis with heterogeneous risk benefit analysis. Traditional strategies such as conventional bronchoscopy have poor performance in locating and acquiring the required tissue. Similarly, while computerized-assisted transthoracic needle biopsy is currently the favored diagnostic procedure, it is associated with complications such as pneumothorax and hemorrhage. Video-assisted thoracoscopic and open surgical biopsies are invasive, require general anesthesia and are therefore not a first-line approach. New techniques such as ultrathin bronchoscopy and image-based guidance technologies are evolving to improve the diagnosis of peripheral lung lesions. Virtual bronchoscopy and electromagnetic navigation systems are novel technologies based on assisted-computerized tomography images that guide the bronchoscopist toward the target peripheral lesion. This article provides a comprehensive review of these emerging technologies.

Diagnostic yield of electromagnetic navigational bronchoscopy

OBJECTIVES

Peripheral lung nodules (PLNs) are a common and diagnostically challenging finding. Electronavigational bronchoscopy (ENB) is used to increase the diagnostic yield and is considered safe. Multiple factors have been correlated with a better diagnostic yield. We sought to assess the effect of nodule characteristics and prior workup on the diagnostic yield in ENB.

METHODS

This was a retrospective chart review of 98 ENB procedures in a community referral center. Two investigators reviewed patients' charts and images independently. Multiple logistic regression analyses was used to determine if factors such as bronchus sign, ground glass opacification (GGO), distance from pleura, prior use of endobronchial ultrasound (EBUS) and positron emission tomography (PET) had an impact on the diagnostic yield.

RESULTS

We evaluated 98 ENBs performed in 92 patients. Most of the lesions were in the upper lobes. The diagnostic yield was 60%. A PET scan was performed prior to ENB in 47% of cases. EBUS was performed in 24% of cases. Bronchus sign was present in 60% of cases and GGO in only 6% of nodules. The odds ratio for diagnostic yield with a bronchus sign was 1.89 [95% confidence interval (CI): 0.83-4.33] and with nodules showing GGO characteristics it was 4.51 (95% CI: 0.51-39.68). Pneumothorax occurred in 6% of cases.

CONCLUSION

In our cohort, diagnostic yield was 60% with a 6% pneumothorax rate. A suggestive trend for the presence of bronchus sign on computed tomography scan, albeit statistically nonsignificant, as a predictor for improved diagnostic yield needs to be validated in a larger cohort.

The effect of general anesthesia versus intravenous sedation on diagnostic yield and success in electromagnetic navigation bronchoscopy

BACKGROUND

Navigational bronchoscopy is utilized to guide biopsies of peripheral lung nodules and place fiducial markers for treatment of limited stage lung cancer with stereotactic body radiotherapy. The type of sedation used for this procedure remains controversial. We performed a retrospective chart review to evaluate the differences of diagnostic yield and overall success of the procedure based on anesthesia type.

METHODS

Electromagnetic navigational bronchoscopy was performed using the superDimension software system. Once the targeted lesion was within reach, multiple tissue samples were obtained. Statistical analysis was used to correlate the yield with the type of sedation among other factors. A successful procedure was defined if a diagnosis was made or a fiducial marker was adequately placed.

RESULTS

Navigational bronchoscopy was performed on a total of 120 targeted lesions. The overall complication rate of the procedure was 4.1%. The diagnostic yield and success of the procedure was 74% and 87%, respectively. Duration of the procedure was the only significant difference between the general anesthesia and IV sedation groups (mean, 58 vs. 43 min, P=0.0005). A larger tumor size was associated with a higher diagnostic yield (P=0.032). All other variables in terms of effect on diagnostic yield and an unsuccessful procedure did not meet statistical significance.

CONCLUSIONS

Navigational bronchoscopy is a safe and effective pulmonary diagnostic tool with relatively low complication rate. The diagnostic yield and overall success of the procedure does not seem to be affected by the type of sedation used.

Meta-analysis of the diagnostic yield and safety of electromagnetic navigation bronchoscopy for lung nodules

OBJECTIVE

This meta-analysis is to evaluate the overall diagnostic yield and accuracy of electromagnetic navigation bronchoscopy (ENB)-based targeted biopsies in detecting peripheral lesions.

METHODS

A systematic search in PubMed was performed using "electromagnetic navigation bronchoscopy" crossed with "peripheral lesions" and "lung nodules". Test performance characteristics with the use of forest plots, summary receiver operating characteristic curves (SROCs) and bivariate random effects were summarized using Meta-Disc software. Adverse events and complications were recorded if reported.

RESULTS

A total of 17 studies (1,106 patients with peripheral lung lesions) were included in this analysis. The pooled sensitivity, specificity, positive likelihood ratios (PLRs), negative likelihood ratios (NLRs), and diagnostic odds ratios (DORs) of ENB was 82%, 100%, 19.36, 0.23, and 97.62, respectively. The area under the curve (AUC) for the SROC was 0.9786. No procedure-related complication was found.

CONCLUSIONS

ENB is an effective and safe procedure in diagnosing peripheral lung lesions.

Patient dose simulations for scanning-beam digital x-ray tomosynthesis of the lungs

PURPOSE

An improved method of image guidance for lung tumor biopsies could help reduce the high rate of false negatives. The aim of this work is to optimize the geometry of the scanning-beam digital tomography system (SBDX) for providing real-time 3D tomographic reconstructions for target verification. The unique geometry of the system requires trade-offs between patient dose, imaging field of view (FOV), and tomographic angle.

METHODS

Tomosynthetic angle as a function of tumor-to-detector distance was calculated. Monte Carlo Software (PCXMC) was used to calculate organ doses and effective dose for source-to-detector distances (SDDs) from 90 to 150 cm, patient locations with the tumor at 20 cm from the source to 20 cm from the detector, and FOVs centered on left lung and right lung as well as medial and distal peripheries of the lungs. These calculations were done for two systems, a SBDX system and a GE OEC-9800 C-arm fluoroscopic unit. To evaluate the dose effect of the system geometry, results from PCXMC were calculated using a scan of 300 mAs for both SBDX and fluoroscopy. The Rose Criterion was used to find the fluence required for a tumor SNR of 5, factoring in scatter, air-gap, system geometry, and patient position for all models generated with PCXMC. Using the calculated fluence for constant tumor SNR, the results from PCXMC were used to compare the patient dose for a given SNR between SBDX and fluoroscopy.

RESULTS

Tomographic angle changes with SDD only in the region near the detector. Due to their geometry, the source array and detector have a peak tomographic angle for any given SDD at a source to tumor distance that is 69.7% of the SDD assuming constant source and detector size. Changing the patient location in order to increase tomographic angle has a significant effect on organ dose distribution due to geometrical considerations. With SBDX and fluoroscopy geometries, the dose to organs typically changes in an opposing manner with changing patient location. When tumor SNR is held constant (i.e., x-ray fluence is scaled appropriately), SBDX gives 2-10 times less dose than fluoroscopy for the same conditions within the typical range of patient locations. The relative position of the patient (as a percent of SDD) has a much more significant impact on dose than either SDD or patient position. The patient position providing the minimum dose for a given tumor SNR and SDD is approximately the same as the position of maximum tomographic angle.

CONCLUSIONS

SBDX offers a significant dose advantage over currently used C-arm fluoroscopy. The patient location with lowest dose coincides with the location of maximum tomographic angle. In order to provide adequate space for the patient and for the pulmonologists' equipment, a SDD of 100 cm is recommended.