Fiducial marker placement with electromagnetic navigation bronchoscopy: a subgroup analysis of the prospective, multicenter NAVIGATE study

[The role of endoscopy in the management of peripheral pulmonary nodules, part 2: Treatment]

The management of peripheral lung nodules is challenging, requiring specialized skills and sophisticated technologies. The diagnosis now appears accessible to advanced endoscopy (see Part 1), which can also guide treatment of these nodules; this second part provides an overview of endoscopy techniques that can enhance surgical treatment through preoperative marking, and stereotactic radiotherapy treatment through fiduciary marker placement. Finally, we will discuss how, in the near future, these advanced endoscopic techniques will help to implement ablation strategy.

CyberKnife® stereotactic radiation therapy for stage I lung cancer and pulmonary oligometastases: is fiducial implantation still relevant?-a cohort study

Background

Few studies have investigated whether there is a difference in local control or overall survival rates following treatment with robotic stereotactic body radiation therapy (SBRT) with or without prior fiducial marker implantation. Our study aimed to investigate this in patients with primary or secondary lung tumors.

Methods

A retrospective study was conducted at the Institut de Cancérologie de Lorraine of patients treated for primary lung cancer or pulmonary oligometastases with SBRT from January 2013 to July 2016. We included patients at least 18 years old who had stage I non-small cell lung cancer (NSCLC) or lung metastases and a follow-up of at least 1 month.

Results

A total of 294 patients were included. Tumors included 122 lung metastases, 89 stage I NSCLC, and 83 non-histologically confirmed lung lesions. The tracking methods were Synchrony® in 191 cases (119 gold seeds and 72 coils) and Xsight® Spine with 4D computed tomography in 103 cases. Median follow-up was 31.6 months [interquartile range (IQR), 18.1-50.2 months]. The two- and five-year probability of local control were respectively 92.22% [95% confidence interval (CI): 0.89-0.95] and 85.35% (95% CI: 0.79-0.99). The two- and five-year probability of overall survival were respectively 87.46% and 72.77% (P=0.586). Local control rates did not significantly differ between techniques at 2 and 5 years (P=0.685) (gold seeds, coils or Xsight® Spine) within tumors grouped by location, gross tumor volume (GTV) (respectively P=0.9, P=0.7, and P=0.4), planning target volume (PTV) (respectively P=0.4, P=0.9, and P=0.7), or PTV/GTV ratio (respectively P=0.6, P=0.6, and P=0.5). Metastasis-free survival and Overall survival rates did not significantly differ between techniques at 2 and 5 years (P=0.664 and P=0.586, respectively). There were no grade 4 or 5 toxicities and only one grade 3 pneumonitis and one grade 3 pneumothorax.

Conclusions

Fiducial-less SBRT using Xsight® Spine is a safe alternative to Synchrony® using gold seeds or coils, with comparable local control and overall survival rates and a similar toxicity profile.

Fiducial markers for stereotactic lung radiation therapy: review of the transthoracic, endovascular and endobronchial approaches

Stereotactic body radiation therapy is an alternative to surgery for early-stage, inoperable peripheral non-small cell lung cancer. As opposed to linear accelerator (linac)-based (e.g. gating) and free-breathing techniques, CyberKnife® with Synchrony® technology allows accurate radiation delivery by means of a real-time respiratory motion tracking system using, in most cases, metal fiducial markers (FMs) placed in the vicinity of the target. The aims of this review are as follows. First, to describe the safety and efficacy of the transthoracic, endovascular and endobronchial FM insertion techniques for peripheral pulmonary lesions (PPLs). Second, to analyse performance in terms of the migration and tracking rates of different FM types. Recent developments in FM tracking for central lesions will also be reviewed. In conclusion, for PPLs, the endobronchial approach provides a low rate of pneumothorax, offers the possibility of concurrent diagnostic sampling for both the PPL and the lymph nodes, and, finally, reduces the intervention time compared to other techniques. In this context, coil-tailed and coil-spring FMs have shown the lowest migration rate with a consequently high tracking rate.

Can bronchoscopically implanted anchored electromagnetic transponders be used to monitor tumor position and lung inflation during deep inspiration breath-hold lung radiotherapy?

PURPOSE

To evaluate the efficacy of using bronchoscopically implanted anchored electromagnetic transponders (EMTs) as surrogates for 1) tumor position and 2) repeatability of lung inflation during deep-inspiration breath-hold (DIBH) lung radiotherapy.

METHODS

41 patients treated with either hypofractionated (HF) or conventional (CF) lung radiotherapy on an IRB approved prospective protocol using coached DIBH were evaluated for this study. Three anchored EMTs were bronchoscopically implanted into small airways near or within the tumor. DIBH treatment was gated by tracking the EMT positions. Breath-hold cone-beam-CTs (CBCTs) were acquired prior to every HF treatment or weekly for CF patients. Retrospectively, rigid registrations between each CBCT and the breath-hold planning CT were performed to match to 1) spine 2) EMTs and 3) tumor. Absolute differences in registration between EMTs and spine were analyzed to determine surrogacy of EMTs for lung inflation. Differences in registration between EMTs and tumor were analyzed to determine surrogacy of EMTs for tumor position. The stability of the EMTs was evaluated by analyzing the difference between inter-EMT displacements recorded at treatment from that of the plan for the CF patients, as well as the geometric residual (GR) recorded at the time of treatment.

RESULTS

219 CBCTs were analyzed. The average differences between EMT centroid and spine registration among all CBCTs were 0.45±0.42cm, 0.29±0.28cm, and 0.18±0.15cm in superior-inferior (SI), anterior-posterior (AP) and lateral directions, respectively. Only 59% of CBCTs had differences in registration <0.5cm for EMT centroid compared to spine, indicating that lung inflation is not reproducible from simulation to treatment. The average differences between EMT centroid and tumor registration among all CBCTs were 0.13±0.13cm, 0.14±0.13cm and 0.12±0.12cm in SI, AP and lateral directions, respectively. 95% of CBCTs resulted in <0.5cm change between EMT centroid and tumor registration, indicating that EMT positions correspond well with tumor position during treatments. Six out of the 7 recorded CF patients had average differences in inter-EMT displacements to be ≤0.26cm and average GR ≤0.22cm, indicating that the EMTs are stable throughout treatment.

CONCLUSIONS

Bronchoscopically implanted anchored EMTs are good surrogates for tumor position and are reliable for maintaining tumor position when tracked during DIBH treatment, as long as the tumor size and shape are stable. Large differences in registration between EMTs and spine for many treatments suggest that lung inflation achieved at simulation is often not reproduced. This article is protected by copyright. All rights reserved.

[Application and Progress of Electromagnetic Navigation Bronchoscopy in Department of Thoracic Surgery]

Lung cancer ranks the first cancer-related morbidity and mortality in China. With the development and penetration of imaging technology, increasing small pulmonary peripheral Nodules (SPPNs) have been detected. However, precise location and diagnosis of SPPNs is still a tough problem for clinical diagnosis and treatment in department of thoracic surgery. With the development of electromagnetic navigation bronchoscopy (ENB), it provides a novel minimally invasive method for the diagnosis and treatment of SPPNs. In this review, we summarized the application and progress of ENB in preoperative positioning, diagnosis, and local treatment, then, discussed the clinical application of ENB in the hybrid operating room.
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NAVIGATE 24-Month Results: Electromagnetic navigation bronchoscopy for pulmonary lesions at 37 centers in Europe and the United States

INTRODUCTION

Electromagnetic navigation bronchoscopy (ENB) is a minimally invasive, image-guided approach to access lung lesions for biopsy or localization for treatment. However, no studies have reported prospective 24-month follow-up from a large, multinational, generalizable cohort. This study evaluated ENB safety, diagnostic yield, and usage patterns in an unrestricted, real-world observational design.

METHODS

The NAVIGATE single-arm, pragmatic cohort study (NCT02410837) enrolled subjects at 37 academic and community sites in 7 countries with prospective 24-month follow-up. Subjects underwent ENB using the superDimension navigation system versions 6.3 to 7.1. The prespecified primary endpoint was procedure-related pneumothorax requiring intervention or hospitalization.

RESULTS

A total of 1,388 subjects were enrolled for lung lesion biopsy (1,329; 95.7%), fiducial marker placement (272; 19.6%), dye marking (23; 1.7%), and/or lymph node biopsy (36; 2.6%). Concurrent endobronchial ultrasound-guided staging occurred in 456 subjects. General anesthesia (78.2% overall, 56.6% Europe, 81.4% US), radial endobronchial ultrasound (50.6%, 4.0%, 57.4%), fluoroscopy (85.0%, 41.7%, 91.0%), and rapid on-site evaluation use (61.7%, 17.3%, 68.5%) differed between regions. Pneumothorax and bronchopulmonary hemorrhage occurred in 4.7% and 2.7% of subjects, respectively (3.2% [primary endpoint] and 1.7% requiring intervention or hospitalization). Respiratory failure occurred in 0.6%. The diagnostic yield was 67.8% (range 61.9%-70.7%; 55.2% Europe, 69.8% US). Sensitivity for malignancy was 62.6%. Lung cancer clinical stage was I-II in 64.7% (55.3% Europe, 65.8% US).

CONCLUSIONS

Despite a heterogeneous cohort and regional differences in procedural techniques, ENB demonstrates low complications and a 67.8% diagnostic yield while allowing biopsy, staging, fiducial placement, and dye marking in a single procedure.

Cone beam CT augmented fluoroscopy allows safe and efficient diagnosis of a difficult lung nodule

Background

Detection of small peripheral lung nodules is constantly increasing with the development of low dose computed tomography lung cancer screening programs. A tissue diagnosis is often required to confirm malignity, with endobronchial biopsies being associated with a lower pneumothorax rate than percutaneous approaches. Endoscopic diagnosis of peripheral small size lung nodules is however often challenging using traditional bronchoscopy and endobronchial ultrasound alone. New virtual bronchoscopic navigation techniques such as electromagnetic navigational bronchoscopy (ENB) have developed to improve peripheral navigation, with diagnostic yield however remaining in the 30–50% range for small lesions. Recent studies have shown the benefits of combining Cone beam computed tomography (CBCT) with ENB to improve diagnostic yield to up to 83%. The use of ENB however remains limited by disposable cost, bronchus sign dependency and inaccuracies due to CT to body divergence.

Case presentation

This case report highlights the feasibility and usefulness of CBCT-guided bronchoscopy for the sampling of lung nodules difficult to reach through traditional bronchoscopy because of nodule size and peripheral position. Procedure was scheduled in a mobile robotic hybrid operating room with patient under general anaesthesia. CBCT acquisition was performed to localize the target lesion and plan the best path to reach it into bronchial tree. A dedicated software was used to segment the lesion and the bronchial path which 3D outlines were automatically fused in real time on the fluoroscopic images to augment live guidance. Navigation to the lesion was guided with bronchoscopy and augmented fluoroscopy alone. Before the sampling, CBCT imaging was repeated to confirm the proper position of the instrument into the lesion. Four transbronchial needle aspirations (TBNA) were performed and the tissue analysis showed a primary lung adenocarcinoma.

Conclusions

CBCT and augmented fluoroscopy technique is a safe and effective and has potential to improve early stage peripheral lesions endobronchial diagnostic yield without ENB. Additional studies are warranted to confirm its safety, efficacy and technical benefits, both for diagnosis of oncological and non-oncological disease and for endobronchial treatment of inoperable patients.

Comparison of technical success and safety of transbronchial versus percutaneous CT-guided fiducial placement for SBRT of lung tumors

OBJECTIVE

To evaluate the technical success and safety of transbronchial (bronchoscopic) fiducial placement compared to percutaneous CT-guided fiducial placement for stereotactic body radiotherapy (SBRT) of lung tumors.

MATERIALS AND METHODS

This IRB-approved, HIPAA-compliant retrospective study was performed at a single tertiary institution. Consecutive patients undergoing lung fiducial placement for purposes of guiding SBRT (CyberKnife®, Accuray, Inc.) between September 2005 to January 2013 were included in the study. Fiducial seeds were placed percutaneously with CT guidance or transbronchially with bronchoscopic guidance. We compared procedure-related complications (pneumothorax, chest tube placement), technical success (defined as implantation enabling adequate treatment planning with CT simulation) and migration rate. The need for repeat procedures and their mode was noted. Statistical analysis was performed using Fisher exact and Chi square probability tests.

RESULTS

Two hundred and forty-four patients with lung tumors and 272 fiducial seed placements were included in the study. Two hundred and twenty-one of the 272 (81.2%) fiducial markers were placed percutaneously and 51/272 (18.8%) were placed transbronchially. Pneumothorax was seen in 73/221 (33%) of percutaneously-placed fiducials and in 4/51 (7.8%) of transbronchial placements (p<0.001). No significant difference was seen in the rate of chest tube placement between the two groups: 20/221 (9%) of percutaneously placed fiducials and 2/51 (3.9%) of transbronchially placed fiducials (p=0.39). Fifteen of the 51 (29%) of fiducial placements with transbronchial approach were unsuccessful, as discovered at radiotherapy planning session, and required a repeat procedure. Nine of the 15 (60%) of repeat procedures were performed percutaneously, 5/15 (33%) were placed during repeat bronchoscopy, and 1/15 (7%) was placed at transesophageal endoscopic ultrasound. No repeat fiducial placements were required for patients who had the fiducials placed percutaneously (p<0.001), with a technical success rate of 100%.

CONCLUSION

Transbronchial fiducial marker placement has a significantly higher rate of failed seed placements requiring repeat procedures in comparison to percutaneous placement. Complication rate of pneumothorax requiring chest drain placement is similar between the two approaches.

The Impact of Biopsy Tool Choice and Rapid On-Site Evaluation on Diagnostic Accuracy for Malignant Lesions in the Prospective: Multicenter NAVIGATE Study

BACKGROUND

The diagnostic yield of electromagnetic navigation bronchoscopy (ENB) is impacted by biopsy tool strategy and rapid on-site evaluation (ROSE) use. This analysis evaluates usage patterns, accuracy, and safety of tool strategy and ROSE in a multicenter study.

METHODS

NAVIGATE (NCT02410837) evaluates ENB using the superDimension navigation system (versions 6.3 to 7.1). The 1-year analysis included 1215 prospectively enrolled subjects at 29 United States sites. Included herein are 416 subjects who underwent ENB-aided biopsy of a single lung lesion positive for malignancy at 1 year. Use of a restricted number of tools (only biopsy forceps, standard cytology brush, and/or bronchoalveolar lavage) was compared with an extensive multimodal strategy (biopsy forceps, cytology brush, aspirating needle, triple needle cytology brush, needle-tipped cytology brush, core biopsy system, and bronchoalveolar lavage).

RESULTS

Of malignant cases, 86.8% (361/416) of true positive diagnoses were obtained using extensive multimodal strategies. ROSE was used in 300/416 cases. The finding of malignancy by ROSE reduced the total number of tools used. A malignant ROSE call was obtained in 71% (212/300), most (88.7%; 188/212) by the first tool used (49.5% with aspirating needle, 20.2% with cytology brush, 17.0% with forceps). True positive rates were highest for the biopsy forceps (86.9%) and aspirating needle (86.6%). Use of extensive tool strategies did not increase the rates of pneumothorax (5.5% restricted, 2.8% extensive) or bronchopulmonary hemorrhage (3.6% restricted, 1.1% extensive).

CONCLUSION

These results suggest that extensive biopsy tool strategies, including the aspirating needle, may provide higher true positive rates for detecting lung cancer without increasing complications.

Electromagnetic Navigation Bronchoscopy-Guided Dye Marking for Localization of Pulmonary Nodules

BACKGROUND

Electromagnetic navigation bronchoscopy (ENB)-guided dye marking is a useful localization modality for small pulmonary nodules. The purpose of this study was to evaluate the efficacy and safety of intraoperative full virtual ENB-guided dye marking.

METHODS

Patients who underwent full virtual ENB-guided dye marking without adjunct intraoperative imaging (fluoroscopy or cone beam computed tomography) for small pulmonary nodules were investigated retrospectively. Efficacy was evaluated on the basis of the success rates of dye marking (visible dye mark) and nodule localization, and safety was evaluated on the basis of the rate of ENB-related complications.

RESULTS

ENB-guided dye marking was performed on 164 nodules in 134 patients. Twenty-seven (20.1%) patients had multiple nodules. The total number of dye-marking attempts was 241, and the mean number of markings per nodule was 1.5±0.7. The mean ENB procedure duration was 30±15.1 min. No ENB-related complications were observed. The success rate of dye marking was 86.7% (209/241), and that of localization was 94.5% (155/164). Among 63 nodules with multiple dye-marking attempts, 62 (98.4%) were successfully localized. In 101 nodules with a single dye-marking attempt, 88 (87.1%) were localized with the visceral pleural dye mark. Additionally, 6 (5.9%) nodules could be localized with the needle hole on the visceral pleura. The number of dye-marking attempts was a significant factor in the success of localization (1.5±0.7 versus 1.1±0.3, p=0.01).

CONCLUSIONS

Full virtual ENB-guided dye marking was effective and safe for the localization of small pulmonary nodules. A multiple dye-marking strategy is recommended to achieve a high success rate.

Advanced Diagnostic and Therapeutic Bronchoscopy: Technology and Reimbursement

Advanced interventional pulmonary procedures of the airways, pleural space, and mediastinum continue to evolve and be refined. Health care, finance, and clinical professionals are challenged by both the indications and related coding complexities. As the scope of interventional pulmonary procedures expands with advanced technique and medical innovation, program planning and ongoing collaboration among clinicians, finance executives, and reimbursement experts are key elements for success. We describe advanced bronchoscopic procedures, appropriate Current Procedural Terminology coding, valuations, and necessary modifiers to fill the knowledge gap between basic and advanced procedural coding. Our approach is to balance the description of procedures with the associated coding in a way that is of use to the proceduralist, the coding specialist, and other nonclinical professionals.

The feasibility of navigation bronchoscopy-guided pulmonary microcoil localization of small pulmonary nodules prior to thoracoscopic surgery

Background

Accurate preoperative localization of small pulmonary nodules facilitates the rapid and precise video-assisted thoracoscopic surgery (VATS). This study aims to evaluate the feasibility, safety, and efficacy of navigation bronchoscopy-guided pulmonary microcoil placement for preoperative pulmonary nodule localization.

Methods

Twelve lung lesions were simulated by mixing lipiodol in three porcine models. After 1 week, two microcoils per lesion were deployed under bronchoscopic guidance. Computed tomography scans were then performed 1 day, 1 week, 2 weeks, and 4 weeks after the deployment to assess the position of the microcoils relative to the lesions. Surgical resection of the simulated lesions was performed under fluoroscopy 5 weeks after the deployment and the accuracy, stability, and associated complications of the microcoil localization were evaluated. Following this, an exploratory clinical study was conducted on three patients with pure ground-glass pulmonary nodules.

Results

The mean diameter of the twelve simulated lung lesions was 9.55±2.36 mm, and the mean distance from the pleura to the lesions was 8.29±2.99 mm. Twenty-four pulmonary microcoils were implanted in the bronchi surrounding the lesions. Four weeks later, the mean distance between the microcoils and the center of the lesions was 16.12±8.97 mm and the average migration of the microcoils relative to the baseline position (1 day after implantation) was 3.48±4.56 mm. All microcoils and target lesions were successfully resected in both the animal experiment and clinical study and no complications, such as pneumothorax, were observed during marker implantation or postoperative follow-up.

Conclusions

The preoperative localization of pulmonary nodules by navigation bronchoscopy-guided microcoil placement is a safe, stable, and effective technique with minimal complication risk. This procedure can assist subsequent thoracoscopic resection.

Interventional Pulmonology: A Brave New World

Interventional pulmonology is a dynamic and evolving field in respiratory medicine. Advances have improved the ability to diagnose and manage diseases of the airways. A shift toward early detection of malignant disease has generated a focus on innovative diagnostic techniques. With patient populations living longer with malignant and benign diseases, the role for interventional bronchoscopy has grown. In cancer groups, novel immunotherapies have improved the prospects of clinical outcomes and reignited a focus on optimizing patient performance status to enable access to anticancer therapy. This review discusses current and emerging diagnostic modalities and therapeutic approaches available to manage airway diseases.

[Advances of Electromagnetic Navigation Bronchoscopy for Peripheral Pulmonary Lesions]

The incidence of peripheral pulmonary lesions (PPLs) is growing following the adoption of lung cancer screening by low-dose chest CT. The diagnosis and treatment of pulmonary nodules is one of the most difficult problems. Based on the electromagnetic positioning technology, the electromagnetic navigation bronchoscope is guided to the pulmonary nodules for biopsy or treatment, providing a new minimally invasive diagnosis and treatment method for suspicious lung lesions. This paper provides an overview of the current status and progress of electromagnetic navigation bronchoscopy in the diagnosis and treatment of peripheral pulmonary diseases.

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.

Pleural dye marking of lung nodules by electromagnetic navigation bronchoscopy

INTRODUCTION

Electromagnetic navigation bronchoscopy (ENB)-guided pleural dye marking is useful to localize small peripheral pulmonary nodules for sublobar resection.

OBJECTIVE

To report findings on the use of ENB-guided dye marking among participants in the NAVIGATE study.

METHODS

NAVIGATE is a prospective, multicentre, global and observational cohort study of ENB use in patients with lung lesions. The current subgroup report is a prespecified 1-month interim analysis of ENB-guided pleural dye marking in the NAVIGATE United States cohort.

RESULTS

The full United States cohort includes 1215 subjects from 29 sites (April 2015 to August 2016). Among those, 23 subjects (24 lesions) from seven sites underwent dye marking in preparation for surgical resection. ENB was conducted for dye marking alone in nine subjects while 14 underwent dye marking concurrent with lung lesion biopsy, lymph node biopsy and/or fiducial marker placement. The median nodule size was 10 mm (range 4-22) and 83.3% were <20 mm in diameter. Most lesions (95.5%) were located in the peripheral third of the lung, at a median of 3.0 mm from the pleura. The median ENB-specific procedure time was 11.5 minutes (range 4-38). The median time from dye marking to resection was 0.5 hours (range 0.3-24). Dye marking was adequate for surgical resection in 91.3%. Surgical biopsies were malignant in 75% (18/24).

CONCLUSION

In this study, ENB-guided dye marking to localize lung lesions for surgery was safe, accurate and versatile. More information is needed about surgical practice patterns and the utility of localization procedures.