Prospective Randomized Trial for Image-Guided Biopsy Using Cone-Beam CT Navigation Compared with Conventional CT

Cone Beam Computed Tomography for the Interventional Oncologist: A Practical Approach

Transarterial treatment of liver tumors is becoming increasingly common and is considered first- or second-line therapy for many tumor types and stages. Such therapies are heavily dependent on imaging during the procedures; while angiography remains the mainstay of intraprocedural therapies, cone beam computed tomography (CBCT) is becoming increasingly commonly used to guide therapy. This article describes the role of CBCT during transarterial therapies and offers guidance as to how CBCT can be optimally used for these procedures.

Fully automatic online geometric calibration for non-circular cone-beam CT orbits using fiducials with unknown placement

BACKGROUND

Cone-beam CT (CBCT) with non-circular scanning orbits can improve image quality for 3D intraoperative image guidance. However, geometric calibration of such scans can be challenging. Existing methods typically require a prior image, specialized phantoms, presumed repeatable orbits, or long computation time.

PURPOSE

We propose a novel fully automatic online geometric calibration algorithm that does not require prior knowledge of fiducial configuration. The algorithm is fast, accurate, and can accommodate arbitrary scanning orbits and fiducial configurations.

METHODS

The algorithm uses an automatic initialization process to eliminate human intervention in fiducial localization and an iterative refinement process to ensure robustness and accuracy. We provide a detailed explanation and implementation of the proposed algorithm. Physical experiments on a lab test bench and a clinical robotic C-arm scanner were conducted to evaluate spatial resolution performance and robustness under realistic constraints.

RESULTS

Qualitative and quantitative results from the physical experiments demonstrate high accuracy, efficiency, and robustness of the proposed method. The spatial resolution performance matched that of our existing benchmark method, which used a 3D-2D registration-based geometric calibration algorithm.

CONCLUSIONS

We have demonstrated an automatic online geometric calibration method that delivers high spatial resolution and robustness performance. This methodology enables arbitrary scan trajectories and should facilitate translation of such acquisition methods in a clinical setting.

Time-Driven Activity-Based Cost Comparison of Osteoid Osteoma Ablation Techniques

OBJECTIVE

Compare the cost of performing an osteoid osteoma ablation using cone beam CT (CBCT) with overlay fluoroscopic guidance to ablation using conventional CT (CCT) guidance and microwave ablation (MWA) to radiofrequency ablation (RFA).

METHODS

An 11-year retrospective study was performed of all patients undergoing osteoid osteoma ablation. Ablation equipment included a Cool tip RFA probe (Covidien, Minneapolis, Minnesota) or a Neuwave PR MWA probe (Ethicon, Rariton, New Jersey). The room times as well as immediate recovery time were recorded for each case. Cost analysis was then performed using time-driven activity-based costing for rate-dependent variables including salaries, equipment depreciation, room time, and certain supplies. Time-independent costs included the disposable interventional radiology supplies and ablation systems. Costs were reported for each service providing care and using conventional cost accounting methods with variable and fixed expenditures.

RESULTS

A total of 91 patients underwent 96 ablation procedures in either CBCT (n = 66) or CCT (n = 30) using either MWA (n = 51) or RFA (n = 45). The anesthesia induction (22.7 ± 8.7 min versus 15.9 ± 7.2 min, P < .001), procedure (64.7 ± 27.5 min versus 47.3 ± 15.3 min; P = .001), and room times (137.7 ± 33.7 min versus 103.9 ± 22.6. min; P < .001) were significantly longer for CBCT procedures. The procedure time did not differ significantly between MWA and RFA (62.1 ± 27.4 min versus 56.1 ± 23.3 min; P = .27). Multiple regression analysis demonstrated lower age (P = .046), CBCT use (P = .001), RFA use (P = .02), and nonsupine patient position (P = .01) significantly increased the total procedural cost. After controlling for these variables, the total cost of CBCT ($5,981.32 ± $523.93 versus $5,378.93 ± $453.12; P = .001) remained higher than CCT and the total cost of RFA ($5,981.32 ± $523.93 versus $5,674.43 ± $549.14; P = .05) approached a higher cost than MWA.

CONCLUSION

The use of CBCT with overlay fluoroscopic guidance for osteoid osteoma ablation resulted in longer in-room times and greater cost when compared with CCT. These cost considerations should be weighed against potential radiation dose advantage of CBCT when choosing an image guidance modality. Younger age, RFA use, and nonsupine patient position additionally contributed to higher costs.

Cone-beam CT-based Navigation With Augmented Fluoroscopy of the Airways for Image-guided Bronchoscopic Biopsy of Peripheral Pulmonary Nodules: A Prospective Clinical Study

BACKGROUND

Cone-beam computed tomography (CBCT) and augmented fluoroscopy (AF), in which intraprocedural CBCT data is fused with fluoroscopy, have been utilized as a novel image-guidance technique for biopsy of peripheral pulmonary lesions. The aim of this clinical study is to determine the safety and diagnostic performance of CBCT-guided bronchoscopy with advanced software tools for procedural planning and navigational guidance with AF of the airways for biopsy of peripheral pulmonary nodules.

METHODS

Fifty-two consecutive subjects were prospectively enrolled in the AIRWAZE study (December 2018 to October 2019). Image-guided bronchoscopic biopsy procedures were performed under general anesthesia with specific ventilation protocols in a hybrid operating room equipped with a ceiling-mounted C-arm system. Procedural planning and image-guided bronchoscopy with CBCT and AF were performed using the Airwaze investigational device.

RESULTS

A total of 58 pulmonary lesions with a median size of 19.0 mm (range 7 to 48 mm) were biopsied. The overall diagnostic yield at index procedure was 87.9% (95% CI: 77.1%-94.0%). No severe adverse events related to CBCT-guided bronchoscopy, such as pneumothorax, bleeding, or respiratory failure, were observed.

CONCLUSION

CBCT-guided bronchoscopic biopsy with augmented fluoroscopic views of the airways and target lesion for navigational guidance is technically feasible and safe. Three-dimensional image-guided navigation biopsy is associated with high navigational success and a high diagnostic yield for peripheral pulmonary nodules.

Chinese expert consensus on cone-beam CT-guided diagnosis, localization and treatment for pulmonary nodules

Cone-beam computed tomography (CBCT) system can provide real-time 3D images and fluoroscopy images of the region of interest during the operation. Some systems can even offer augmented fluoroscopy and puncture guidance. The use of CBCT for interventional pulmonary procedures has grown significantly in recent years, and numerous clinical studies have confirmed the technology's efficacy and safety in the diagnosis, localization, and treatment of pulmonary nodules. In order to optimize and standardize the technical specifications of CBCT and guide its application in clinical practice, the consensus statement has been organized and written in a collaborative effort by the Professional Committee on Interventional Pulmonology of China Association for Promotion of Health Science and Technology.

Percutaneous microwave ablation for lung tumors: a retrospective case-control study of conventional CT and C-arm CT guidance

Background

Although conventional computed tomography (cCT) is the mainstream guidance equipment for lung microwave ablation (MWA), C-arm CT can provide 3-dimensional (3D) CT-like images reconstructed from 2-dimensional (2D) digital subtraction angiography (DSA) information within 8 seconds, highlighting its utility as a new guidance tool. This retrospective case-control study was performed to evaluate the clinical performance of percutaneous MWA for lung tumors using cCT and C-arm CT guidance.

Methods

From April 2015 to April 2020, 101 consecutive patients with solitary lung tumors who underwent percutaneous MWA at our single center (Zhengzhou, China) were divided into 2 groups: the cCT group (n=56), with unarmed puncture, and the C-arm CT group (n=45), with iGuide navigation-assisted puncture. The primary endpoints were technical success, technical efficacy, puncture scoring (PS), and complete ablation (CA) rate. The secondary endpoints were complications, median progression-free survival (mPFS), and median overall survival (mOS).

Results

The technical success rates were 100% in both the C-arm CT group and cCT group. The technical efficacies were 93.3% and 91.1% in the C-arm CT group and cCT group, respectively, with no statistical difference (P=0.67). The PS (2.9 vs. 2.5, P=0.02), total procedure time (TPT; 39.3 vs. 50.0 min, P<0.001), puncture time (PT; 12.6 vs. 15.7 min, P=0.001), and irradiation effective dose (ED; 15.2 vs. 20.9 mSV, P<0.001) showed significances between patients in the C-arm CT and those in the cCT group. The ablation time (AT; 9.1 vs. 9.6 min, P=0.36), CA rate (93.3% vs. 92.9%, P=0.93), local tumor progression (LTP) rate (11.1% vs. 8.9%, P=0.98), complications, mPFS (9.5 vs. 10.1 months, P=0.52), and mOS (37.9 vs. 38.8 months, P=0.67) showed no statistically significant difference between the 2 groups.

Conclusions

C-arm CT guidance is as feasible and effective as cCT for lung tumor MWA, which can increase PS and decrease TPT.

Enhancing Nodule Biopsy Through Technology Integration

Technology in navigating to peripheral pulmonary nodules has improved in recent years. The recent integration of a robotic platform using shape-sensing technology and mobile cone-beam computed tomography imaging technology has enhanced confidence in sampling lesions with intraprocedural imaging by complimenting the pre-planned navigation to peripheral pulmonary nodules. We present 2 cases using the software integration that improved the robotic catheter positioning to allow for diagnostic specimens to be obtained in the initial biopsies.

Using 3D polylines to improve cone-beam CT-guided percutaneous transthoracic needle biopsy

OBJECTIVES

To investigate the diagnostic accuracy of using 3D polylines (3DPs) to improve cone-beam CT (CBCT) virtual navigation (VN)-guided percutaneous transthoracic needle biopsies (PTNB) of pulmonary lesions.

METHODS

From May 2021 to November 2021, patients (81 males and 41 females; age, 65 ± 12 years) who underwent CBCT VN with 3DPs for PTNB of pulmonary lesions were retrospectively reviewed. Fluoroscopic visibility of target lesions was evaluated using captured images from a Bull's eye view. Diagnostic accuracy was calculated, and complications were assessed.

RESULTS

The mean size of biopsied lesions was 23 ± 13 mm (range: 6-75 mm). Overall, 13.9% (17/122) were small pulmonary nodules (diameter ≤1 cm), and 68.0% (83/122) of biopsied lesions were fluoroscopic visible. The overall diagnostic accuracy was 94.3%. The diagnostic accuracy for visible and invisible lesions was 94.0 and 94.9%, respectively (p = 0.843), and 100% for small pulmonary nodules. Major complications occurred in 8.2% (10/122; eight pneumothorax with chest tube insertion, one hemoptysis with transfusion, and one air embolism) of patients.

CONCLUSION

CBCT VN with 3DP guidance provide a real-time outline of pulmonary lesions, thus enabling a reliable and accurate PTNB.

ADVANCES IN KNOWLEDGE

3DP guidance could be useful technique for CBCT-guided PTNB, especially in small pulmonary nodules.

Combining Shape-Sensing Robotic Bronchoscopy With Mobile Three-Dimensional Imaging to Verify Tool-in-Lesion and Overcome Divergence: A Pilot Study

Objective

To determine whether CT-to-body divergence can be overcome to improve the diagnostic yield of peripheral pulmonary nodules with the combination of shape-sensing robotic-assisted bronchoscopy (SSRAB) and portable 3-dimensional (3D) imaging.

Patients and Methods

A single-center, prospective, pilot study was conducted from February 9, 2021, to August 4, 2021, to evaluate the combined use of SSRAB and portable 3D imaging to visualize tool-in-lesion as a correlate to diagnostic yield.

Results

Thirty lesions were subjected to biopsy in 17 men (56.7%) and 13 women (43.3%). The median lesion size was 17.5 mm (range, 10-30 mm), with the median airway generation of 7 and the median distance from pleura of 14.9 mm. Most lesions were in the upper lobes (18, 60.0%). Tool-in-lesion was visualized at the time of the procedure in 29 lesions (96.7%). On the basis of histopathologic review, 22 (73.3%) nodules were malignant and 6 (20.0%) were benign. Two (6.7%) specimens were suggestive of inflammation, and the patients elected observation. The mean number of spins was 2.5 (±1.6) with a mean fluoroscopy time of 8.7 min and a mean dose area product of 50.3 Gy cm² (±32.0 Gy cm²). There were no episodes of bleeding or pneumothorax. The diagnostic yield was 93.3%.

Conclusion

This pilot study shows that the combination of mobile 3D imaging and SSRAB of pulmonary nodules appears to be safe and feasible. In conjunction with appropriate anesthetic pathways, nodule motion and divergence can be overcome in most patients.

Trial Registration

https://clinicaltrials.gov Identifier NCT04740047

C-Arm Cone-Beam CT Virtual Navigation versus Conventional CT Guidance in the Transthoracic Lung Biopsy: A Case-Control Study

C-arm cone-beam computed tomography (CBCT) virtual navigation-guided lung biopsy has been developed in the last decade as an alternative to conventional CT-guided lung biopsy. This study aims to compare the biopsy accuracy and safety between these two techniques and explores the risk factors of biopsy-related complications. A total of 217 consecutive patients undergoing conventional CT- or C-arm CBCT virtual navigation-guided lung biopsy from 1 June 2018 to 31 December 2019 in this single-center were retrospectively reviewed. Multiple factors (e.g., prior emphysema, lesion size, etc.) were compared between two biopsy techniques. The risk factors of complications were explored by using logistic regression. The patients’ median age and male-to-female ratio were 63 years and 2.1:1, respectively. Eighty-two (82) patients (37.8%) underwent conventional CT-guided biopsies, and the other 135 patients (62.2%) C-arm CBCT virtual navigation-guided biopsies. Compared with patients undergoing C-arm CBCT virtual navigation-guided lung biopsies, patients undergoing conventional CT-guided lung biopsies showed higher needle repositioning rate, longer operation time, and higher effective dose of X-ray (52.4% vs. 6.7%, 25 min vs. 15 min, and 13.4 mSv vs. 7.6 mSv, respectively; p < 0.001, each). In total, the accurate biopsy was achieved in 215 of 217 patients (99.1%), without a significant difference between the two biopsy techniques (p = 1.000). The overall complication rates, including pneumothorax and pulmonary hemorrhage/hemoptysis, are 26.3% (57/217), with most minor complications (56/57, 98.2%). The needle repositioning was the only independent risk factor of complications with an odds ratio of 6.169 (p < 0.001). In conclusion, the C-arm CBCT virtual navigation is better in percutaneous lung biopsy than conventional CT guidance, facilitating needle positioning and reducing radiation exposure. Needle repositioning should be avoided because it brings about more biopsy-related complications.

Phantom study for comparison between computed tomography- and C-Arm computed tomography-guided puncture applied by residents in radiology

PURPOSE

 Comparison of puncture deviation and puncture duration between computed tomography (CT)- and C-arm CT (CACT)-guided puncture performed by residents in training (RiT).

METHODS

 In a cohort of 25 RiTs enrolled in a research training program either CT- or CACT-guided puncture was performed on a phantom. Prior to the experiments, the RiT's level of training, experience playing a musical instrument, video games, and ball sports, and self-assessed manual skills and spatial skills were recorded. Each RiT performed two punctures. The first puncture was performed with a transaxial or single angulated needle path and the second with a single or double angulated needle path. Puncture deviation and puncture duration were compared between the procedures and were correlated with the self-assessments.

RESULTS

 RiTs in both the CT guidance and CACT guidance groups did not differ with respect to radiologic experience (p = 1), angiographic experience (p = 0.415), and number of ultrasound-guided puncture procedures (p = 0.483), CT-guided puncture procedures (p = 0.934), and CACT-guided puncture procedures (p = 0.466). The puncture duration was significantly longer with CT guidance (without navigation tool) than with CACT guidance with navigation software (p < 0.001). There was no significant difference in the puncture duration between the first and second puncture using CT guidance (p = 0.719). However, in the case of CACT, the second puncture was significantly faster (p = 0.006). Puncture deviations were not different between CT-guided and CACT-guided puncture (p = 0.337) and between the first and second puncture of CT-guided and CACT-guided puncture (CT: p = 0.130; CACT: p = 0.391). The self-assessment of manual skills did not correlate with puncture deviation (p = 0.059) and puncture duration (p = 0.158). The self-assessed spatial skills correlated positively with puncture deviation (p = 0.011) but not with puncture duration (p = 0.541).

CONCLUSION

 The RiTs achieved a puncture deviation that was clinically adequate with respect to their level of training and did not differ between CT-guided and CACT-guided puncture. The puncture duration was shorter when using CACT. CACT guidance with navigation software support has a potentially steeper learning curve. Spatial skills might accelerate the learning of image-guided puncture.

KEY POINTS

  · The CT-guided and CACT-guided puncture experience of the RiTs selected as part of the program "Researchers for the Future" of the German Roentgen Society was adequate with respect to the level of training.. · Despite the lower collective experience of the RiTs with CACT-guided puncture with navigation software assistance, the learning curve regarding CACT-guided puncture may be faster compared to the CT-guided puncture technique.. · If the needle path is complex, CACT guidance with navigation software assistance might have an advantage over CT guidance..

CITATION FORMAT

· Meine TC, Hinrichs JB, Werncke T et al. Phantom study for comparison between computed tomography- and C-Arm computed tomography-guided puncture applied by residents in radiology. Fortschr Röntgenstr 2021; DOI: 10.1055/a-1586-2733.

Advances in Diagnostic Bronchoscopy

The increase in incidental discovery of pulmonary nodules has led to more urgent requirement of tissue diagnosis. The peripheral pulmonary nodules are especially challenging for clinicians. There are various modalities for diagnosis and tissue sampling of pulmonary lesions, but most of these modalities have their own limitations. This has led to the development of many advanced technical modalities, which have empowered pulmonologists to reach the periphery of the lung safely and effectively. These techniques include thin/ultrathin bronchoscopes, radial probe endobronchial ultrasound (RP-EBUS), and navigation bronchoscopy—including virtual navigation bronchoscopy (VNB) and electromagnetic navigation bronchoscopy (ENB). Recently, newer technologies—including robotic-assisted bronchoscopy (RAB), cone-beam CT (CBCT), and augmented fluoroscopy (AF)—have been introduced to aid in the navigation to peripheral pulmonary nodules. Technological advances will also enable more precise tissue sampling of smaller peripheral lung nodules for local ablative and other therapies of peripheral lung cancers in the future. However, we still need to overcome the CT-to-body divergence, among other limitations. In this review, our aim is to summarize the recent advances in diagnostic bronchoscopy technology.

Workflow-Based Design and Evaluation of a Device for CBCT-Guided Biopsy

Biopsies for personalized cancer care can be performed with cone beam computed tomography (CBCT) guidance, but manual needle manipulation remains an issue due to X-ray exposure to physicians. Modern CBCT scanners integrate today real-time imaging and software assistance for needle planning. In this paper, these available features are exploited to design a novel device offering an intermediate level of assistance between simple passive mechanical devices of limited efficiency, and advanced robotic devices requiring adapted procedure workflows. Our resulting system is built to limit its impact on the current manual practice. It is patient-mounted and provides remote control of needle orientation and insertion. A multilayer phantom is specifically developed to reproduce interactions between the needle and soft abdominal tissues. It is used to experimentally evaluate the device added value by comparing assisted versus manual needle insertions. The device is shown to help reducing X-ray exposure by a factor 4, without impacting the accuracy obtained manually.

A systematic review on the application of the hybrid operating room in surgery: experiences and challenges

The hybrid operating room has been widely applied in different surgery sub-specialties. We aim to identify the advantages of hybrid operating rooms by focusing on intraoperative imaging and explore what to do for further improving its application. We searched related literature in websites including Pubmed, MEDLINE, Web of science, using the keywords ("hybrid operating room" or "integrated operating room" or "multifunctional operating room") and ("surgery" or "technique" or "intervention" or "radiology"). All the searched papers were screened and underwent quality evaluation. A total of 30 literature was eventually identified after full-text screening. These articles covered 10 countries and presented data for 15,558 individuals. The median sample size was 536 (range 8-12,804). Application of the hybrid operating room in general surgery, neurosurgery, thoracic surgery, urology, gynaecologic and obstetrics surgery, cardiovascular surgery, was summarized. Four different operative indicators were applied (operative duration, mortality rate, operation success rate and complication rate). A hybrid OR could significantly increase the operation success rate and reduce operative duration, mortality rates, and complication rates. Further efforts could be made to reduce radiation exposure in the hybrid operating room and increase its cost-effectiveness ratio.

Cone-Beam CT-Guided Lung Biopsies: Results in 94 Patients

BACKGROUND

The aim of this study was to evaluate the diagnostic capacity of Cone-Beam computed tomography (CT)-guided transthoracic percutaneous biopsies on lung lesions in our setting and to detect risk factors for possible complications.

METHODS

Retrospective study of 98 biopsies in 94 patients, performed between May 2017 and January 2020. To obtain them, a 17G coaxial puncture system and a Siemens Artis Zee Floor vc21 archwire were used. Descriptive data of the patients, their position at the time of puncture, location and size of the lesions, number of cylinders extracted, and complications were recorded. Additionally, the fluoroscopy time used in each case, the doses/area and the estimated total doses received by the patients were recorded.

RESULTS

Technical success was 96.8%. A total of 87 (92.5%) malignant lesions and 3 (3.1%) benign lesions were diagnosed. The sensitivity was 91.5% and the specificity was 100%. We registered three technical failures and three false negatives initially. Complications included 38 (38.8%) pneumothorax and 2 (2%) hemoptysis cases. Fluoroscopy time used in each case was 4.99 min and the product of the dose area is 11,722.4 microGy/m².

CONCLUSION

The transthoracic biopsy performed with Cone-Beam CT is accurate and safe in expert hands for the diagnosis of lung lesions. Complications are rare and the radiation dose used was not excessive.

Application of the Hybrid Operating Room in Surgery: A Systematic Review

BACKGROUND AND OBJECTIVE

The hybrid operating room has been widely applied in surgery, including neurology, general surgery, gynecology, and obstetrics. By reviewing application of the hybrid operating room in different categories of surgery, we aim to summarize both advantages and disadvantages of the hybrid operating room and discuss what to do for further improving the application of it.

METHODS

We searched related literature in websites including Pubmed, MEDLINE, Web of science, using the keywords "hybrid operating room", "surgery", "technique", "intervention", and "radiology". All the searched papers were screened and underwent quality evaluation. The eventually selected papers were carefully read, with related information extracted and summarized.

RESULTS

After screening and assessment, a total of 29 literature was collected. Application of the hybrid operating room in general surgery, neurosurgery, thoracic surgery, urology, gynecologic and obstetrics surgery, and cardiovascular surgery was summarized. Both advantages and disadvantages of the hybrid operating room were discussed in order to improve application of the hybrid operating room in surgery.

CONCLUSIONS

Surgeries performed in the hybrid operating room take advantages over those conventional operating rooms mainly in terms of higher procedure accuracy, less operative time, and less risk of hemorrhage during the transportation between radiology departments and operating suites. Further efforts should be made to reduce radiation exposure from imaging systems equipped in the hybrid operating room and increase cost-effectiveness ratio of the hybrid operating room.

Diagnostic Accuracy of Percutaneous Transthoracic Needle Lung Biopsies: A Multicenter Study

Objective

To measure the diagnostic accuracy of percutaneous transthoracic needle lung biopsies (PTNBs) on the basis of the intention-to-diagnose principle and identify risk factors for diagnostic failure of PTNBs in a multi-institutional setting.

Materials and Methods

A total of 9384 initial PTNBs performed in 9239 patients (mean patient age, 65 years [range, 20–99 years]) from January 2010 to December 2014 were included. The accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of PTNBs for diagnosis of malignancy were measured. The proportion of diagnostic failures was measured, and their risk factors were identified.

Results

The overall accuracy, sensitivity, specificity, PPV, and NPV were 91.1% (95% confidence interval [CI], 90.6–91.7%), 92.5% (95% CI, 91.9–93.1%), 86.5% (95% CI, 85.0–87.9%), 99.2% (95% CI, 99.0–99.4%), and 84.3% (95% CI, 82.7–85.8%), respectively. The proportion of diagnostic failures was 8.9% (831 of 9384; 95% CI, 8.3–9.4%). The independent risk factors for diagnostic failures were lesions ≤ 1 cm in size (adjusted odds ratio [AOR], 1.86; 95% CI, 1.23–2.81), lesion size 1.1–2 cm (1.75; 1.45–2.11), subsolid lesions (1.81; 1.32–2.49), use of fine needle aspiration only (2.43; 1.80–3.28), final diagnosis of benign lesions (2.18; 1.84–2.58), and final diagnosis of lymphomas (10.66; 6.21–18.30). Use of cone-beam CT (AOR, 0.31; 95% CI, 0.13–0.75) and conventional CT-guidance (0.55; 0.32–0.94) reduced diagnostic failures.

Conclusion

The accuracy of PTNB for diagnosis of malignancy was fairly high in our large-scale multi-institutional cohort. The identified risk factors for diagnostic failure may help reduce diagnostic failure and interpret the biopsy results.

Cone beam navigation bronchoscopy: the next frontier

Navigation bronchoscopy has reached a new horizon in its evolution. Combining with real-time imaging modalities, such as cone-beam computed tomography (CBCT) and augmented fluoroscopy (AF), navigation success can finally be confirmed with high degree of accuracy in real-time. With utilization of this modality, additional clinical observations are being made to help address the CT-body divergence problem and further improve navigation accuracy. This review focuses on description of CBCT navigation technique, provide tips on addressing CT-Body divergence, and review evidence for CBCT applications in navigation bronchoscopy.

CBCT-Based Image Guidance for Percutaneous Access: Electromagnetic Navigation Versus 3D Image Fusion with Fluoroscopy Versus Combination of Both Technologies-A Phantom Study

PURPOSE

We set out to compare three types of three-dimensional CBCT-based imaging guidance modalities in a phantom study: image fusion with fluoroscopy (IF), electromagnetic navigation (EMN) and the association of both technologies (CEMNIF).

MATERIALS AND METHODS

Four targets with a median diameter of 11 mm [first quartile (Q1): 10; third quartile (Q3): 12] with acute angle access (z-axis < 45°) and four targets of 10 mm [8-15] with large angle access (z-axis > 45°) were defined on an abdominal phantom (CIRS, Meditest, Tabuteau, France). Acute angle access targets were punctured using IF, EMN or CEMNIF and large angle access targets with EMN by four operators with various experiences. Efficacy (target reached), accuracy (distance between needle tip and target center), procedure time, radiation exposure and reproducibility were explored and compared.

RESULTS

All targets were reached (100% efficacy) by all operators. For targets with acute angle access, procedure times (EMN: 265 s [236-360], IF: 292 s [260-345], CEMNIF: 320 s [240-333]) and accuracy (EMN: 3 mm [2-5], IF: 2 mm [1-3], CEMNIF: 3 mm [2-4]) were similar. Radiation exposure (EMN: 0; IF: 708 mGy.cm² [599-1128]; CEMNIF: 51 mGy.cm² [15-150]; p < 0.001) was significantly higher with IF than with CEMNIF and EMN. For targets with large angle access, procedure times (EMN: 345 s [259-457], CEMNIF: 425 s [340-473]; p = 0.01) and radiation exposure (EMN: 0, CEMIF: 159 mGy.cm² [39-316]; p < 0.001) were significantly lower with EMN but with lower accuracy (EMN: 4 mm [4-6] and CEMNIF: 4 mm [3, 4]; p = 0.01). The operator's experience did not impact the tested parameters regardless of the technique.

CONCLUSION

In this phantom study, EMN was not limited to acute angle targets. Efficacy and accuracy of puncture for acute angle access targets with EMN, IF or CEMNIF were similar. CEMNIF is more accurate for large angle access targets at the cost of a slightly higher procedure time and radiation exposure.

Cone-Beam CT-Assisted Ablation of Renal Tumors: Preliminary Results

INTRODUCTION

Renal ablation is a recognized treatment modality for small renal masses. Cone-beam CT (CBCT) has been recently used in interventional oncology as a promising new guidance device, but this technology still needs to be validated for renal ablations. We aimed to assess the technical success of CBCT applications in renal ablative treatments.

MATERIALS AND METHODS

Between March 2016 and June 2018, 14 patients (mean age 69, range 54-83, 7F, 7M) underwent 21 renal ablations for histologically proven renal cell carcinoma (RCC). All treatments were performed with ultrasound (US) and CBCT guidance under general anesthesia in a dedicated angiography room setting. CBCT was mainly used to assess needle placement and to exclude complications at the end of the procedure. In two small lesions (< 1 cm), pre-acquired CBCT was co-registered with real-time US to obtain a US-CBCT fusion image guidance for tumor ablation.

RESULTS

Whether used alone or in combination with other imaging modalities, CBCT was proven to be technically successful in all 21 procedures to guide or assist tumor ablation. A primary technical efficacy of thermal ablation was achieved in 19/21 ablations (90.1%) at 1 month. Mean procedure duration was 100.2 min (range 160-64). Mean length of hospital stay was 2 days (range 1-10 days). All patients are still under active surveillance for a mean follow-up of 14.5 months (range 4-26 months).

CONCLUSIONS

CBCT for renal ablation guidance is a viable tool. Larger series are needed to compare it to MDCT.

Role of cone-beam CT augmented by navigational software in the single-session management of gastrointestinal hemorrhage and infected deep postoperative fluid collections

Utilization of cone-beam CT with navigational software augmentation allows performance of both vascular and nonvascular interventions in a traditional fluoroscopy suite without need for additional hardware. The improvements in target identification and procedure time associated with use of these technologies suggest that they may be particularly beneficial in emergent settings where decreased procedure time correlates with improved outcomes. We illustrate these potential advantages through the successful single-session management of a clinically unstable patient with both gastrointestinal (GI) hemorrhage and infected postoperative fluid collections.

Using the Hybrid Operating Room in Thoracic Surgery: A Paradigm Shift

We describe the integration of the hybrid operation room cone-beam computed tomography (CT) scan technology into the practice of general thoracic surgery. The combination of the following three techniques: (1) cone-beam CT scan augmented navigational bronchoscopy, (2) cone-beam CT-guided percutaneous biopsy and/or fiducial placement, and (3) fiducial or image-guided video-assisted thoracic surgery resection, into a single-stage, single-provider procedure allows for diagnosis and treatment in one setting. Rapid on-site evaluation of cytological or pathology specimens is key to this "all-in-one" approach. The time from diagnosis to curative treatment can significantly be reduced using the hybrid operation room technology, leading to decreased upstaging, increased survival and facilitating the otherwise difficult intraoperative detection and resection of small and deeper lesions. Not only does this benefit the overall thoracic healthcare of the community but also provides a cost-effective paradigm for the institution.

Transthoracic Rebiopsy for Mutation Analysis in Lung Adenocarcinoma: Outcomes and Risk Factors for the Acquisition of Nondiagnostic Specimens in 199 Patients

PURPOSE

To determine the outcomes of transthoracic rebiopsy for epidermal growth factor receptor (EGFR) mutation in patients with lung adenocarcinoma and to explore the clinical and procedure-related risk factors for the acquisition of nondiagnostic rebiopsy specimens.

PATIENTS AND METHODS

We retrospectively reviewed 367 patients with lung adenocarcinoma who underwent transthoracic core needle biopsy for mutation analysis from September 2011 to October 2016. Of these, 199 patients underwent rebiopsy. Patient characteristics, treatment history, target lesion characteristics, and procedure-related factors were evaluated. The adequacy rate of specimens for mutation analysis was evaluated. Univariable and multivariable analyses were performed to determine the independent predictors of nondiagnostic specimens.

RESULTS

Ninety percent of specimens (179 of 199) were adequate for mutation analysis. The EGFR mutation (exon 18-21) was 65% (117 of 179) and the EGFR T790M mutation 33% (59 of 179) of specimens. In univariable analysis, an internal low-attenuation area in the target lesion (P = .001) and pleural contact (P = .004) on computed tomography were significant risk factors for nondiagnostic specimens. In multivariable analysis, an internal low-attenuation area in the target lesion (odds ratio = 7.333; 95% confidence interval, 1.755-30.633; P = .006) was an independent predictor for acquisition of nondiagnostic specimens.

CONCLUSION

Image-guided transthoracic rebiopsy to obtain specimens for mutation analysis in lung adenocarcinoma provides high diagnostic accuracy, with a low rate of nondiagnostic specimens. The presence of internal low-attenuation area in the target lesion on computed tomography was an independent predictor for acquiring nondiagnostic specimens.

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.

Comparison of Conventional and Cone-Beam CT for Monitoring and Assessing Pulmonary Microwave Ablation in a Porcine Model

PURPOSE

To compare cone-beam computed tomography (CT) with conventional CT for assessing the growth and postprocedural appearance of pulmonary microwave ablation zones.

MATERIALS AND METHODS

A total of 17 microwave ablations were performed in porcine lung in vivo by applying 65 W for 5 minutes through a single 17-gauge antenna. Either CT (n = 8) or CBCT (n = 9) was used for guidance and ablation zone monitoring at 1-minute intervals. Postprocedural noncontrast images were acquired with both modalities. Three independent readers measured the length, width, cross-sectional area, and circularity of the ablation zones on gross tissue samples and CT and cone-beam CT images. The measurements were compared via linear mixed-effects models for postprocedural appearance and with a polynomial mixed effects model for ablation zone growth curves.

RESULTS

On postprocedural images, the differences between cone-beam CT and CT in mean length (3.84 vs 3.86 cm; Δ = -0.02; P = .70), width (2.61 vs 2.56 cm; Δ = 0.06; P = .46), area (7.84 vs 7.65 cm²; Δ = 0.19; P = .35), and circularity (0.85 vs 0.85; Δ = 0.01; P = .62) were not statistically significant after accounting for intersubject and interrater variability. Also, there was no significant difference between CT and cone-beam CT growth curves of the ablation zones during monitoring in terms of length (p_Int. = 1.00; p_Lin.Slope = 0.52; p_Quad.Slope = 0.69); width (p_Int. = 0.83; p_Lin.Slope = 0.98; p_Quad.Slope = 0.79), area (p_Int. = 0.47; p_Lin.Slope = 0.27; p_Quad.Slope = 0.57), or circularity (p_Int. = 0.54; p_Lin.Slope = 0.74; p_Quad.Slope = 0.80). Both CT and cone-beam CT overestimated gross pathologic observations of ablation length, width, and area (P < .001 for all).

CONCLUSIONS

Cone-beam CT was similar to conventional CT when assessing the growth, final size, and shape of pulmonary microwave ablation zones and may be useful for monitoring and evaluating microwave ablations in the lung.

Cone beam computed tomography virtual navigation-guided transthoracic biopsy of small (≤ 1 cm) pulmonary nodules: impact of nodule visibility during real-time fluoroscopy

OBJECTIVE

To evaluate the impact of nodule visibility during real-time fluoroscopy and other biopsy-related variables on the diagnostic accuracy and complication rates of cone beam CT (CBCT) virtual navigation (VN)-guided percutaneous transthoracic needle biopsies (PTNBs) of small (≤1 cm) pulmonary nodules.

METHODS

Patients (99 males and 114 females; age, 62.1 ± 11.1 years) who underwent CBCT VN-guided biopsies for lung nodules ≤ 1 cm were retrospectively reviewed. The visibility of target nodules was assessed on the captured fluoroscopy images. Diagnostic accuracies were calculated and logistic regression analyses were performed to determine independent influencing factors for the correct diagnosis and complications (pneumothoraxes and hemoptysis) in CBCT VN-guided PTNBs, respectively.

RESULTS

Among 213 nodules, 63 (29.6%) were invisible on real-time fluoroscopy during VN. The diagnostic accuracy of CBCT VN-guided PTNBs for the invisible nodules was 76.7%, while for the visible nodules was 89.1% (p = 0.042). In the logistic regression analysis, the visibility of a target nodule (odds ratio = 2.49, p = 0.047) was the only independent influencing factor for a correct diagnosis. As regards complication rates, nodule visibility was not a significant factor for the occurrence of a pneumothorax or hemoptysis.

CONCLUSION

Although nodule visibility on real-time fluoroscopy was an affecting factor for the correct diagnosis, CBCT VN-guided PTNB was feasible for the invisible nodules with diagnostic accuracy of 76.7%. Advance in knowledge: CBCT VN-guided PTNB can be tried safely for the subcentimeter-sized pulmonary nodules regardless of their fluoroscopic visibility.

Percutaneous low-dose CT-guided lung biopsy with an augmented reality navigation system: validation of the technique on 496 suspected lesions

PURPOSE

To validate a CT-navigation system during percutaneous lung biopsy (PLB).

METHODS

Four hundred-ninety-six patients underwent low-dose CT-guided PLB. Lesion diameter (LD), procedural time (PT), histologic validity, lesion distance from pleural surface (DPS), needle distance travelled during procedure (DTP), complications and radiation exposure were recorded.

RESULTS

Hysto-patological diagnosis was obtained in 96.2% cases. Mean PT, DPS, DTP, LD were respectively 29.5min, 12.4mm, 17.9mm, 20.7mm. In cases of major complications (4.6%), higher values of DTP were measured.

CONCLUSIONS

CT-navigation system allowed a good success in terms of diagnosis in small lesions and when a long DTP is required.

Risk factors for haemoptysis after percutaneous transthoracic needle biopsies in 4,172 cases: Focusing on the effects of enlarged main pulmonary artery diameter

OBJECTIVES

To evaluate the risk factors for haemoptysis after cone-beam computed tomography (CBCT)-guided percutaneous transthoracic needle biopsy (PTNB), particularly on whether the enlargement of main pulmonary artery diameter (mPAD) is a risk factor for PTNB-related haemoptysis.

METHODS

4,172 cases of CBCT-guided PTNBs in 3,840 patients were retrospectively included in this study. Various data including mPAD measured on preprocedural CT images were evaluated using logistic regression analyses to determine significant risk factors for both haemoptysis and severe haemoptysis, designated as when blood transfusion, vascular embolisation or cardiopulmonary resuscitation were required to manage patients with haemoptysis.

RESULTS

Haemoptysis occurred in 5.78 % (241/4172) of all PTNB procedures, while severe haemoptysis occurred in 0.18 % (7/4172). Female sex, history of antiplatelet or anticoagulative drugs, prolonged activated partial thromboplastin time, subsolid nodules, cavitary nodules and long pleura-to-target distance were revealed to be independent risk factors for haemoptysis, while mPAD enlargement (> 29.5 mm) was not. Regarding severe haemoptysis, however, mPAD enlargement was demonstrated to be an independent risk factor along with the presence of subsolid and cavitary target nodules.

CONCLUSION

mPAD enlargement was not a significant risk factor for PTNB-related haemoptysis; however, it was a significant risk factor for severe haemoptysis.

KEY POINTS

• mPAD enlargement was a significant risk factor for severe PTNB-related haemoptysis. • mPAD can be useful in screening high-risk patients for severe haemoptysis. • Subsolid or cavitary nodule was another significant risk factor for severe haemoptysis.

Recent advances in diagnostic bronchoscopy

The field of diagnostic bronchoscopy has been revolutionized in the last decade primarily with the advent of endobronchial ultrasound (EBUS) but also with the addition of multiple different techniques for "guided-bronchoscopy". These advances have had a substantial impact in the management of lung cancer with bronchoscopy now providing both diagnosis and mediastinal staging in a single procedure. EBUS has, in fact, become the first choice for staging of the mediastinum over cervical mediastinoscopy (CM). Although EBUS is now a well-established technique, there are continuous efforts from the scientific community to improve its diagnostic performance, and these will be reviewed in this manuscript. The term "guided-bronchoscopy" was recently coined to describe a myriad of techniques that guide our bronchoscopes or bronchoscopic tools into the periphery of the lungs in addition to our conventional fluoroscopy. Electromagnetic and non-electromagnetic navigation, thin and ultrathin scopes, as well as radial-probe EBUS have collectively increased our yield for smaller peripheral lung lesions and continue to evolve. Despite this improved diagnostic yield, there is still ample room for improvement and newer techniques are under way. With new therapies available for patients with interstitial lung disease, achieving a specific histologic diagnosis is now of paramount importance. Given the high morbidity and mortality of surgical biopsies, bronchoscopic cryobiopsy is being rapidly adopted as a safer and effective alternative, and it is likely going to play a major role in the management of these diseases in the near future. This manuscript we will focus on recent advances in EBUS, guided-bronchoscopy, and the use of cryobiopsy.