Electromagnetic Navigation Bronchoscopy-Guided Fiducial Placement for Robotic Stereotactic Radiosurgery of Lung Tumors: A Feasibility Study

doi:10.1378/chest.07-0522

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Volume 132, Issue 3, September 2007, Pages 930-935

https://doi.org/10.1378/chest.07-0522 Get rights and content

Background

Stereotactic radiosurgery (Cyberknife; Accuray Incorporated; Sunnyvale, CA) is a treatment option for patients who are medically unfit to undergo lung tumor resection. For precise tumor ablation, the Cyberknife requires fiducial marker placement in or near the target tumor. Fiducial placement under transthoracic CT guidance is associated with a high risk of iatrogenic pneumothorax. Electromagnetic navigation bronchoscopy (ENB) may offer a less morbid alternative to accurately deploy fiducials to bronchoscopically invisible peripheral lung lesions.

Objective

Open-label, feasibility study to assess fiducial placement in peripheral lung tumors by ENB.

Method

Consecutive patients with peripheral lung tumors and who were evaluated to be nonsurgical candidates underwent fiducial placement under ENB. This procedure was considered successful if fiducials were placed in or near the tumors and remained in place without migration for radiosurgery to proceed. The need for alternative or additional intrathoracic fiducial placement was documented as procedure failure.

Results

A total of 39 fiducials markers were successfully deployed in eight of nine patients (89%). Of these eight successful cases, seven had fiducials placed directly within the tumor (88%). At Cyberknife planning, 7 to 10 days after fiducial placement, 35 of 39 fiducial markers (90%) were still in place and were adequate to allow radiosurgery to proceed. No immediate bronchoscopic complications were observed. One patient had a COPD exacerbation. Another patient returned within 1 day with transient, self-limiting fever.

Conclusions

ENB can be used to deploy fiducial markers for Cyberknife radiosurgery of lung tumors safely and accurately without the complications associated with transthoracic placement.

Section snippets

Materials and Methods

Nine consecutive patients who were referred for bronchoscopic fiducial placement were recruited between September 2005 and April 2006. All patients had peripheral lung tumors and no CT evidence of endobronchial pathology. The cases were reviewed at a multidisciplinary thoracic oncology clinic, and seven were deemed inoperable. Two additional patients declined surgery when informed of the potential surgical risks and complications due to their medical comorbidities. The indications for all nine

Results

Thirty-nine fiducial markers were placed in nine patients. Mean age of these patients was 69 ± 13 years (range, 46 to 92 years). Histology, size, and stage of the tumors are listed in Table 1. Majority of these patients had multiple comorbidities and poor pulmonary function. Mean FEV₁ was 39 ± 10% of predicted.

During ENB, the mean number of registration points used was 6 ± 1 (range, 5 to 7). Mean registration error was 6.1 ± 0.2 (range, 5.9 to 6.5 mm), while the documented navigation error was

Discussion

Cyberknife radiosurgery has emerged as an alternative for patients with lung cancers who are inoperable for medical reasons.¹¹ Bronchoscopic fiducial placement in the thorax is more attractive than either transthoracic or intravascular deployment because of the improved side effects profile. Transthoracic fiducial placement has a reported pneumothorax rate of 13%.¹¹ This percentage may not be representative of the actual incidence because the pneumothorax rate for transthoracic CT-guided

ACKNOWLEDGMENT

Arthur Dea and Robert Garland from Interventional Pulmonology, Beth Israel Deaconess Medical Center, Boston, assisted with manuscript editing and data collection.

References (15)

G Schreiber et al.
Performance characteristics of different modalities for diagnosis of suspected lung cancer: summary of published evidence
Chest
(2003)
WA Baaklini et al.
Diagnostic yield of fiberoptic bronchoscopy in evaluating solitary pulmonary nodules
Chest
(2000)
Y Schwarz et al.
Real-time electromagnetic navigation bronchoscopy to peripheral lung lesions using overlaid CT images: the first human study
Chest
(2006)
M Imura et al.
Insertion and fixation of fiducial markers for setup and tracking of lung tumors in radiotherapy
Int J Radiat Oncol Biol Phys
(2005)
RI Whyte et al.
Stereotactic radiosurgery for lung tumors: preliminary report of a phase I trial
Ann Thorac Surg
(2003)
KM Yeow et al.
Risk factors of pneumothorax and bleeding: multivariate analysis of 660 CT-guided coaxial cutting needle lung biopsies
Chest
(2004)
V Prasad et al.
Embolotherapy of pulmonary arteriovenous malformations: efficacy of platinum versus stainless steel coils
J Vasc Interv Radiol
(2004)

There are more references available in the full text version of this article.

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The role of endoscopy in the management of peripheral pulmonary nodules, part 2: Treatment
2024, Revue des Maladies Respiratoires
Si la découverte de nodules pulmonaires périphériques est devenue un problème majeur en pratique oncologique, leur diagnostic apparaît aujourd’hui accessible aux techniques d’endoscopie avancée. Ces techniques permettent également de guider le traitement de ces nodules. Dans cette deuxième partie, nous détaillerons comment les techniques d’endoscopie avancée peuvent aider le traitement chirurgical par le biais d’un marquage préopératoire, d’une part, et le traitement par radiothérapie stéréotaxique par le biais de la pose de marqueur fiduciaire, d’autre part. Enfin nous aborderons comment elles pourront, dans un futur proche, également participer à l’ablation endoscopique de ces nodules.
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.
Clinical Factors That Affect Fiducial Tracking in Robotic SABR for Lung Tumors
2023, Advances in Radiation Oncology
SABR is a treatment option for patients with lung tumors that employs fiducials to track tumors during the breathing cycle. Currently, there is a paucity of data on how relative fiducial location and patient clinical characteristics affect fiducial tracking and clinical outcomes. This study aimed to identify factors that reduce the number of fiducials tracked with respiratory motion management during SABR.
An institutional review board–approved retrospective review was performed of patients receiving robotic SABR for lung tumors at our institution from 2016 to 2019. Clinical data including demographics, medical history, treatment data, and follow-up were collected. Fiducial geometries were obtained with Velocity contouring software and MATLAB. Mann-Whitney U, χ², and t tests were completed using MedCalc.
A total of 73 patients with 77 treatments were identified. The χ² analysis revealed that chronic obstructive pulmonary disease was associated with having 3 or more fiducials tracked (P = .034). Tumors in lower lobes were associated with higher rates of uncertainty errors (P = .015). The number of fiducials tracked had no effect on local tumor control or overall survival, with a median of 36 months of follow-up. A total of 28 treatments had fiducial centroid data available for geometric analysis. The most common tracking errors were rigid body error (RBE; 57%) and spacing errors (36.4%). Spacing errors had a shorter average minimum interfiducial distance than nonspacing errors (1.0 cm vs 1.7 cm, respectively; P = .017). RBE treatments had a longer average maximum distance than non-RBE treatments (4.0 cm vs 3.0 cm; P = .022).
Greater motion in lower lobes can contribute to certain tracking errors that prevent more fiducials from being tracked. Maintaining interfiducial distance between experimentally determined guidelines may limit spacing errors and RBEs, the 2 most common tracking errors. An increased number of patients in a data set may result in stronger correlations between patient and tumor factors and outcomes.
Endobronchially Implanted Real-Time Electromagnetic Transponder Beacon–Guided, Respiratory-Gated SABR for Moving Lung Tumors: A Prospective Phase 1/2 Cohort Study
2023, Advances in Radiation Oncology
Endobronchial electromagnetic transponder beacons (EMT) provide real-time, precise positional data of moving lung tumors. We report results of a phase 1/2, prospective, single-arm cohort study evaluating the treatment planning effects of EMT-guided SABR for moving lung tumors.
Eligible patients were adults, Eastern Cooperative Oncology Group 0 to 2, with T1-T2N0 non-small cell lung cancer or pulmonary metastasis ≤4 cm with motion amplitude ≥5 mm. Three EMTs were endobronchially implanted using navigational bronchoscopy. Four-dimensional free-breathing computed tomography simulation scans were obtained, and end-exhalation phases were used to define the gating window internal target volume. A 3-mm expansion of gating window internal target volume defined the planning target volume (PTV). EMT-guided, respiratory-gated (RG) SABR was delivered (54 Gy/3 fractions or 48 Gy/4 fractions) using volumetric modulated arc therapy. For each RG-SABR plan, a 10-phase image-guided SABR plan was generated for dosimetric comparison. PTV/organ-at-risk (OAR) metrics were tabulated and analyzed using the Wilcoxon signed-rank pair test. Treatment outcomes were evaluated using RECIST (Response Evaluation Criteria in Solid Tumours; version 1.1).
Of 41 patients screened, 17 were enrolled and 2 withdrew from the study. Median age was 73 years, with 7 women. Sixty percent had T1/T2 non-small cell lung cancer and 40% had M1 disease. Median tumor diameter was 1.9 cm with 73% of targets located peripherally. Mean respiratory tumor motion was 1.25 cm (range, 0.53-4.04 cm). Thirteen tumors were treated with EMT-guided SABR and 47% of patients received 48 Gy in 4 fractions while 53% received 54 Gy in 3 fractions. RG-SABR yielded an average PTV reduction of 46.9% (P < .005). Lung V5, V10, V20, and mean lung dose had mean relative reductions of 11.3%, 20.3%, 31.1%, and 20.3%, respectively (P < .005). Dose to OARs was significantly reduced (P < .05) except for spinal cord. At 6 months, mean radiographic tumor volume reduction was 53.5% (P < .005).
EMT-guided RG-SABR significantly reduced PTVs of moving lung tumors compared with image-guided SABR. EMT-guided RG-SABR should be considered for tumors with large respiratory motion amplitudes or those located in close proximity to OARs.
Comparison of technical success and safety of transbronchial versus percutaneous CT-guided fiducial placement for SBRT of lung tumors
2021, Journal of Medical Imaging and Radiation Sciences
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.
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.
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%.
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.
Évaluer la réussite technique et la sécurité de la pose de repères transbronchiques (bronchoscopiques) par rapport à la pose de repères percutanés guidés par tomodensitométrie pour la radiothérapie stéréotaxique (SBRT) de tumeurs pulmonaires.
Cette étude rétrospective, approuvée par le comité d'éthique de la recherche et conforme à la loi HIPAA, a été réalisée dans un seul établissement tertiaire. L'étude a porté sur des patients consécutifs ayant subi une implantation de points de repères dans les poumons pour guider la SBRT (CyberKnife®, Accuray, Inc.) entre septembre 2005 et janvier 2013. Les repères fiduciaires ont été placés par voie percutanée avec guidage par tomodensitométrie ou par voie transbronchique avec guidage bronchoscopique. Nous avons comparé les complications liées à la procédure (pneumothorax, pose d'un drain thoracique), le succès technique (défini comme une implantation permettant une planification adéquate du traitement avec une simulation par tomodensitométrie) et le taux de migration. La nécessité de procédures répétées et leur mode ont été notés. L'analyse statistique a été réalisée à l'aide des tests de probabilité Fisher exact et Chi carré.
244 patients atteints de tumeurs pulmonaires et 272 placements de repères fiduciaires ont été inclus dans l'étude. 221/272 (81,2 %) marqueurs fiduciaires ont été placés par voie percutanée et 51/272 (18,8 %) ont été placés par voie transbronchique. Un pneumothorax a été observé dans 73/221 (33%) des repères placés par voie percutanée et dans 4/51 (7,8 %) des placements par voie transbronchique (p<0,001). Aucune différence significative n'a été observée dans le taux de mise en place d'un drain thoracique entre les deux groupes: 20/221 (9 %) des repères placés par voie percutanée et 2/51 (3,9 %) des repères placés par voie transbronchique (p=0,39). 15/51 (29 %) des placements de repères par voie transbronchique ont échoué, comme cela a été constaté lors de la séance de planification de la radiothérapie, et ont nécessité une nouvelle procédure. 9/15 (60 %) des procédures répétées ont été réalisées par voie percutanée, 5/15 (33 %) ont été placés lors d'une nouvelle bronchoscopie et 1/15 (7 %) a été placé lors d'une échographie endoscopique transœsophagienne. Aucun nouveau placement de repère n'a été nécessaire pour les patients chez qui les repères ont été placés par voie percutanée (p<0,001), avec un taux de réussite technique de 100 %.
La pose de marqueurs fiduciaires par voie transbronchique présente un taux d’échec du positionnement des repères significativement plus élevé nécessitant des procédures répétées, par rapport à la pose percutanée. Le taux de complication de pneumothorax nécessitant la pose d'un drain thoracique est similaire entre les deux approche.
Methylene Blue/Collagen Mixture for CT-Guided Presurgical Lung Nodule Marking: High Efficacy and Safety
2020, Journal of Vascular and Interventional Radiology
To assess outcomes of computed tomography (CT)-guided methylene blue/collagen marking of preoperative lung nodules before video-assisted thoracoscopic surgery (VATS) and robotic-assisted thoracic surgery (RATS).
A retrospective cohort study assessing 25 methylene blue/collagen solution CT-guided lung nodule localization procedures on 26 nodules in 25 patients was performed. The procedures were performed by a fellowship-trained radiologist 1–2 hours before scheduled surgery under local anesthesia. Approximately 4–6 ml of methylene blue/collagen solution was injected in a perinodular location under CT guidance with a 19-gauge trocar needle and along the track to the visceral pleural surface. Post-procedural CT images confirmed appropriate lung nodule location marking.
Perinodular CT-guided trocar needle placement was achieved in all marking procedures (n = 26/26). Increased consolidation near the target nodule was also demonstrated in all patients on the post-procedural localized CT scans. One patient with moderate emphysema developed a small to moderate-sized pneumothorax (∼20%–30%), and an 8-Fr thoracentesis catheter was placed under CT guidance before surgery. There was no bleeding or hemoptysis in any patient. Methylene blue/collagen solution was readily visible by the thoracic surgeon in association with all target nodules. One patient required conversion to open procedure due to the proximal portion of the right lower lobe pulmonary artery segmental branch. Of the 26 identified nodules, pathology specimens confirmed the adequacy of nodule resection in all cases.
Preoperative CT-guided methylene blue/collagen solution injection offers a safe and highly effective technique for marking subpleural lung nodules undergoing VATS or RATS.
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2019, Journal of Vascular and Interventional Radiology
To evaluate safety of endovascular coil fiducial placement and compare complication rates with transthoracic fiducial placement in patients with peripheral early-stage lung cancer receiving fiducial markers for stereotactic body radiotherapy (SBRT).
This retrospective study included consecutive patients who received endovascular coils (n = 416 patients, n = 1,335 coils) or transthoracic fiducials (n = 30 patients, n = 80 fiducials) for SBRT between August 2005 and January 2017. During the first 3 years of the study period, patients preferentially received cylindrical platinum fiducial markers by percutaneous transthoracic placement; only patients with contraindications received endovascular coils. Thereafter, patients received endovascular fiducials as the first-line procedure. Endovascular embolization coils were placed via the femoral vein into subsegmental pulmonary artery branches near the tumor. Complications were scored by SIR criteria.
The success rate of endovascular coil placement was 99.8%. One patient developed grade 2 hemoptysis requiring procedure discontinuation. Following placement, 1 patient (0.2%) developed grade 3 cardiac arrhythmia. A total of 36 patients (9%) developed grade 1 complications: mild hemoptysis (n = 4; 1%), small asymptomatic pulmonary infarction or hemorrhage (n = 30; 7%), hypoglycemia (n = 1; 0.2%), and vasovagal episode (n = 1; 0.2%). Following transthoracic marker placement, 4 patients (13%) developed a pneumothorax requiring hospital admission and chest tube (grade 2), 6 patients (20%) developed pneumothorax requiring no intervention (grade 1), 2 patients (7%) experienced asymptomatic pulmonary bleeding, and 1 patient (3%) developed persistent pain.
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The locatable sensor probes for electromagnetic navigation bronchoscopy were provided free of charge by superDimension. superDimension has supported continuing medical education courses at Harvard University through unrestricted educational grants. Dr. Ernst was a member of the Scientific Advisory Board of superDimension and has been reimbursed for time and travel expenses related to that function. Dr. Ernst also had stock options in superDimension, which have been returned in the past. Dr. DeCamp is a member of the Scientific Advisory Board of superDimension and Accuray and has been reimbursed for time and travel expenses related to that function. Neither Dr. Ernst nor Dr. DeCamp were involved in the consenting process. Drs. Anantham, Feller-Kopman, Shanmugham, Berman, Gangadharan, Eberhardt, and Herth have no conflict of interest to report.

A portion of this data was presented as an abstract at the European Respiratory Society Congress, Munich, Germany, 2006.

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ORIGINAL RESEARCHINTERVENTIONAL PULMONOLOGYElectromagnetic Navigation Bronchoscopy-Guided Fiducial Placement for Robotic Stereotactic Radiosurgery of Lung Tumors: A Feasibility Study

Background

Objective

Method

Results

Conclusions

Section snippets

Materials and Methods

Results

Discussion

ACKNOWLEDGMENT

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Int J Radiat Oncol Biol Phys

Ann Thorac Surg

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J Vasc Interv Radiol

ORIGINAL RESEARCH
INTERVENTIONAL PULMONOLOGY
Electromagnetic Navigation Bronchoscopy-Guided Fiducial Placement for Robotic Stereotactic Radiosurgery of Lung Tumors: A Feasibility Study