Comparison Between CBCT and Fusion PET/CT-CBCT Guidance for Lung Biopsies

Computed-Tomography-Guided Lung Biopsy: A Practice-Oriented Document on Techniques and Principles and a Review of the Literature

Computed tomography (CT)-guided lung biopsy is one of the oldest and most widely known minimally invasive percutaneous procedures. Despite being conceptually simple, this procedure needs to be performed rapidly and can be subject to meaningful complications that need to be managed properly. Therefore, knowledge of principles and techniques is required by every general or interventional radiologist who performs the procedure. This review aims to contain all the information that the operator needs to know before performing the procedure. The paper starts with the description of indications, devices, and types of percutaneous CT-guided lung biopsies, along with their reported results in the literature. Then, pre-procedural evaluation and the practical aspects to be considered during procedure (i.e., patient positioning and breathing) are discussed. The subsequent section is dedicated to complications, with their incidence, risk factors, and the evidence-based measures necessary to both prevent or manage them; special attention is given to pneumothorax and hemorrhage. After conventional CT, this review describes other available CT modalities, including CT fluoroscopy and cone-beam CT. At the end, more advanced techniques, which are already used in clinical practice, like fusion imaging, are included.

Histology profiling of lung tumors: tru-cut versus full-core system for CT-guided biopsies

PURPOSE

We aimed to compare the diagnostic yield and procedure-related complications of two different types of systems for percutaneous CT-guided lung biopsy.

MATERIAL AND METHODS

All patients with a lung lesion who underwent a CT-guided lung biopsy at our institution, between January 2019 and 2021, were retrospectively analyzed. The inclusion criteria were: (a) Procedures performed using either a fully automated tru-cut or a semi-automated full-core biopsy needle, (b) CT images demonstrating the position of the needles within the lesion, (c) histopathological result of the biopsy and (d) clinical follow-up for at least 12 months and\or surgical histopathological results. A total of 400 biopsy fulfilling the inclusion criteria were selected and enrolled in the study.

RESULTS

Overall technical success was 100% and diagnostic accuracy was 84%. Tru-cut needles showed a significantly higher diagnostic accuracy when compared to full-core needles (91% vs. 77%, p = 0.0004) and a lower rate of pneumothorax (31% vs. 41%, p = 0.047). Due to the statistically significant different of nodules size between the two groups, we reiterated the statistical analysis splitting our population around the 20 mm cut-off for nodule size. We still observed a significant difference in diagnostic accuracy between tru-cut and full-core needles favoring the former for both smaller and larger lesions (81% vs. 71%, p = 0.025; and 92% vs. 81%; p = 0.01, respectively).

CONCLUSION

Our results demonstrated that the use of automated tru-cut needles is associated with higher histopathological diagnostic accuracy compared to semi-automated full-core needles for CTLB.

PET/CT-aided biopsy of lung lesions enhances diagnostic efficacy, especially for lesions >3cm

Objectives

The purpose of this study was to compare the diagnostic efficacy of PET/CT-aided CT-guided and routine CT-guided transthoracic needle biopsy for lung lesions.

Methods

A total of 458 patients with suspicious lung lesions were referred for CT-guided biopsy, with 227 patients assigned to the PET/CT group and 231 patients assigned to the CT group. The clinical characteristics and diagnostic yield were compared between the two groups. Furthermore, conducting subgroup analysis to evaluate the differences of diagnostic success or failure between the two groups.

Results

The sensitivity and diagnostic accuracy rate differed significantly (P = 0.035, P = 0.048). In the PET/CT group, the values were 95.7% and 96.3%, respectively, while in the CT group, they were 90.1% and 91.9%. When considering non-diagnostic cases, the overall diagnostic success rate increased markedly in PET/CT group (93.0% vs. 83.1%, P = 0.001). In our subgroup analysis, the PET/CT group demonstrated superiority in detecting lesions larger than 3 cm (OR, 4.81; 95CI%, 2.03 - 11.36), while showing a moderate effect in lesions smaller than 3 cm (OR, 1.09; 95CI%, 0.42 - 2.81). Significant effect modification was observed in large lesions in the PET/CT group (P for interaction = 0.023).

Conclusions

18F-FDG-PET/CT enhances the diagnostic efficacy of CT-guided transthoracic needle biopsy for lung lesions, and the incremental value can be modified by lesion size, particularly when the diameter is larger than 3 cm.

Could Maximum SUV be Used as Imaging Guidance in Large Lung Lesions Biopsies? Double Sampling Under PET-CT/XperGuide Fusion Imaging in Inhomogeneous Lung Uptaking Lesions to Show That it can Make a Difference

Introduction: The purpose of this study is to evaluate the diagnostic value of positron emission computed tomography-cone beam computed tomography (PET/CT-CBCT) fusion guided percutaneous biopsy, targeted to the maximum standardized uptake value (SUVmax) and minimum standardized uptake value (SUVmin) of large lung lesions. Materials and Methods: Inside a larger cohort of PET/CT-CBCT guided percutaneous lung biopsies, 10 patients with large pulmonary lesions (diameter > 30 mm) were selected retrospectively. These patients have been subjected to double biopsy sampling respectively in the SUVmax area and in the SUVmin area of the lesion. Technical success has been calculated. For each sample, the percentage of neoplastic, inflammatory, and fibrotic cells was reported. Furthermore, the possibility of performing immunohistochemical or molecular biology investigations to specifically define the biomolecular tumor profile was analyzed. Results: Nine lesions were found to be malignant, one benign (inflammation). Technical success was 100% (10/10) in the SUVmax samples and 70% (7/10) in the SUVmin samples (P-value: .21). In the first group, higher percentages of neoplastic cells were found at pathologic evaluation, while in the second group areas of inflammation and fibrosis were more represented. The biomolecular profile was obtained in 100% of cases (9/9) of the first group, while in the second group only in 33.3% of cases (2/6), with a statistically significant difference between the 2 groups (P-value: .011). Conclusion: A correlation between the standardized uptake value value and the technical success of the biopsy sample has been identified. PET/CT-CBCT guidance allows to target the biopsy in the areas of the tumor which are richer in neoplastic cells, thus obtaining more useful information for the planning of patient-tailored cancer treatments.

Robotics in Interventional Radiology: Review of Current and Future Applications

This review is a brief overview of the current status and the potential role of robotics in interventional radiology. Literature published in the last decades, with an emphasis on the last 5 years, was reviewed and the technical developments in robotics and navigational systems using CT-, MR- and US-image guidance were analyzed. Potential benefits and disadvantages of their current and future use were evaluated. The role of fusion imaging modalities and artificial intelligence was analyzed in both percutaneous and endovascular procedures. A few hundred articles describing results of single or several systems were included in our analysis.

Dual-layer spectral CT fusion imaging for lung biopsies: more accurate targets, diagnostic samplings, and biomarker information?

The increasingly widespread use of computed tomography (CT) has increased the number of detected lung lesions, which are then subjected to needle biopsy to obtain histopathological diagnosis. Obtaining high-quality biopsy specimens is fundamental for diagnosis and biomolecular characterisation that guide therapy decision-making. In order to obtain samples with high diagnostic potential, fusion imaging techniques, such as fusion between positron emission tomography and CT, have been introduced to target the biopsy where there more viable neoplastic cells can be sampled. Nowadays, dual-layer spectral CT represents a novel technology enabling an increased tissue characterisation. In particular, Z-effective images, i.e., colour-coded images based on the effective atomic number of tissue components, provide a higher level of discrimination than usual imaged based on x-ray attenuation in Hounsfield units and offer the potential of a better tissue characterisation. Our hypothesis is based on the future use of data provided by spectral CT, in particular by Z-effective images, as a guide for appropriate biopsy sampling for histopathological and biomolecular characterisation in the era of patient tailored-therapy.

Improving CT-guided transthoracic biopsy diagnostic yield of lung masses using intraprocedural CT and prior PET/CT fusion imaging

Objective

The purpose of this study was to evaluate the usefulness of intraprocedural CT and prior PET/CT fusion imaging in improving the diagnostic yield of CT-guided transthoracic core-needle biopsy (CNB) in lung masses.

Methods

In total, 145 subjects with lung masses suspicious for malignancy underwent image-guided transthoracic CNB. According to imaging modality the subjects were divided into two groups. PET/CT images obtained no more than 14 days before the biopsy were integrated with intraprocedural CT images. The integrated or fused images were then used to plan the puncture sites. The clinical characteristics, diagnostic yield of CNB, diagnostic accuracy rate, procedure-related complications and procedure duration were recorded and compared between the two groups. Final clinical diagnosis was determined by surgical pathology or at least 6-months follow-up. The diagnostic accuracy of CNB was obtained by comparing with final clinical diagnosis.

Results

145 subjects underwent CNB with adequate samples, including 76 in fusion imaging group and 69 in routine group. The overall diagnostic yield and diagnostic accuracy rate were 80.3% (53/66), 82.9% (63/76) for fusion imaging group, 70.7% (41/58), 75.4% (52/69) for routine group, respectively. In addition, the diagnostic yield for malignancy in fusion imaging group (98.1%, 52/53) was higher than that in routine group (81.3%, 39/48). No serious procedure-related complications occurred in both two groups.

Conclusion

CNB with prior PET/CT fusion imaging is particularly helpful in improving diagnostic yield and accurate rate of biopsy in lung masses, especially in heterogeneous ones, thus providing greater potential benefit for patients.

A Fast Image Guide Registration Supported by Single Direction Projected CBCT

Image registration is an important research topic in medical image-guided therapy, which is dedicated to registering the high-dose imaging sequences with low-dose/faster means. Registering computer tomography (CT) scanning sequences with cone beam computer tomography (CBCT) scanning sequences is a typical application and has been widely used in CBCT-guided radiotherapy. The main problem is the difference in image clarity of these two image sequences. To solve this problem, for the single projection image sequence matching tasks encountered in medical practice, a novel local quality based curved section encoding strategy is proposed in this paper, which is called the high-quality curved section (HQCS). As an optimized cross-section regularly encoded along the sequence of image, this curved section could be used in order to solve the matching problem. Referencing the independent ground truth provided by medical image physicians, with an experiment combined with the four most widely used indicators used on image registration, matching performance of HQCS on CT/CBCT datasets was tested with varying clarity. Experimental results show that the proposed HQCS can register the CT/CBCT effectively and outperforms the commonly used methods. Specifically, the proposed HQCS has low time complexity and higher scalability, which indicates that the application enhanced the task of diagnosis.

Interventional Radiology ex-machina: impact of Artificial Intelligence on practice

Artificial intelligence (AI) is a branch of Informatics that uses algorithms to tirelessly process data, understand its meaning and provide the desired outcome, continuously redefining its logic. AI was mainly introduced via artificial neural networks, developed in the early 1950s, and with its evolution into "computational learning models." Machine Learning analyzes and extracts features in larger data after exposure to examples; Deep Learning uses neural networks in order to extract meaningful patterns from imaging data, even deciphering that which would otherwise be beyond human perception. Thus, AI has the potential to revolutionize the healthcare systems and clinical practice of doctors all over the world. This is especially true for radiologists, who are integral to diagnostic medicine, helping to customize treatments and triage resources with maximum effectiveness. Related in spirit to Artificial intelligence are Augmented Reality, mixed reality, or Virtual Reality, which are able to enhance accuracy of minimally invasive treatments in image guided therapies by Interventional Radiologists. The potential applications of AI in IR go beyond computer vision and diagnosis, to include screening and modeling of patient selection, predictive tools for treatment planning and navigation, and training tools. Although no new technology is widely embraced, AI may provide opportunities to enhance radiology service and improve patient care, if studied, validated, and applied appropriately.

PET- and SPECT-based navigation strategies to advance procedural accuracy in interventional radiology and image-guided surgery

INTRODUCTION

Nuclear medicine has a crucial role in interventional strategies where a combination between the increasing use of targeted radiotracers and intraprocedural detection modalities enable novel, but often complex, targeted procedures in both the fields of interventional radiology and surgery. 3D navigation approaches could assist the interventional radiologist or surgeon in such complex procedures.

EVIDENCE ACQUISITION

This review aimed to provide a comprehensive overview of the current application of computer-assisted navigation strategies based on nuclear imaging to assist in interventional radiology and image-guided surgery. This work starts with a brief overview of the typical navigation workflow from a technical perspective, which is followed by the different clinical applications organized based on their anatomical organ of interest.

EVIDENCE SYNTHESIS

Although many studies have proven the feasibility of PET- and SPECT-based navigation strategies for various clinical applications in both interventional radiology and surgery, the strategies are spread widely in both navigation workflows and clinical indications, evaluated in small patient groups. Hence, no golden standard has yet been established.

CONCLUSIONS

Despite that the clinical outcome is yet to be determined in large patient cohorts, navigation seems to be a promising technology to translate nuclear medicine findings, provided by PET- and SPECT-based molecular imaging, to the intervention and operating room. Interventional Nuclear Medicine (iNM) has an exciting future to come using both PET- and SPECT-based navigation.

Role of Fusion Imaging in Image-Guided Thermal Ablations

Thermal ablation (TA) procedures are effective treatments for several kinds of cancers. In the recent years, several medical imaging advancements have improved the use of image-guided TA. Imaging technique plays a pivotal role in improving the ablation success, maximizing pre-procedure planning efficacy, intraprocedural targeting, post-procedure monitoring and assessing the achieved result. Fusion imaging (FI) techniques allow for information integration of different imaging modalities, improving all the ablation procedure steps. FI concedes exploitation of all imaging modalities’ strengths concurrently, eliminating or minimizing every single modality’s weaknesses. Our work aims to give an overview of FI, explain and analyze FI technical aspects and its clinical applications in ablation therapy and interventional oncology.