Society of Interventional Radiology Quality Improvement Standards on Percutaneous Needle Biopsy in Adult and Pediatric Patients

Value of interventional radiology and their contributions to modern medical systems

Interventional radiology (IR) is a unique specialty that incorporates a diverse set of skills ranging from imaging, procedures, consultation, and patient management. Understanding how IR generates value to the healthcare system is important to review from various perspectives. IR specialists need to understand how to meet demands from various stakeholders to expand their practice improving patient care. Thus, this review discusses the domains of value contributed to medical systems and outlines the parameters of success. IR benefits five distinct parties: patients, practitioners, payers, employers, and innovators. Value to patients and providers is delivered through a wide set of diagnostic and therapeutic interventions. Payers and hospital systems financially benefit from the reduced cost in medical management secondary to fast patient recovery, outpatient procedures, fewer complications, and the prestige of offering diverse expertise for complex patients. Lastly, IR is a field of rapid innovation implementing new procedural technology and techniques. Overall, IR must actively advocate for further growth and influence in the medical field as their value continues to expand in multiple domains. Despite being a nascent specialty, IR has become indispensable to modern medical practice.

Does ROSE matter? Evaluation of final diagnostic, PD-L1 immunohistochemistry, and molecular testing yields of CT-guided lung biopsies performed before and after the onset of the COVID-19 pandemic

INTRODUCTION

The onset of the COVID-19 pandemic, with urgent implementation of safety protocols limiting the number of on-site personnel, essentially terminated the use of rapid on-site evaluation (ROSE) for computed tomography (CT)--guided lung biopsies at our institution. The diminished use of ROSE during the pandemic prompted us to reevaluate the potential value of ROSE for CT-guided lung biopsies.

MATERIALS AND METHODS

We retrospectively identified all CT-guided lung biopsies from 2017 to 2022. Associations between the use of ROSE, adequate diagnostic and ancillary testing (programmed death-ligand 1 immunohistochemistry and next-generation sequencing) outcomes, and other factors such as the number of passes performed and lesion size, were evaluated.

RESULTS

Nine hundred twelve CT-guided lung biopsies were performed from 2017 to 2022; 171 (19%) utilized ROSE. The use of ROSE had been steadily decreasing prior to the pandemic but was essentially eliminated with the onset of the pandemic. By univariable analysis, the employment of ROSE was more likely to be associated with an adequate final diagnosis (odds ratio = 2.14, 95% confidence interval: [1.24-3.70], P = 0.006) and successful molecular testing (odds ratio = 2.16, 95% confidence interval: [1.11-4.21], P = 0.024). However, those associations were not present in multivariable analyses that incorporated the number of passes performed or lesion size. There were no differences in diagnostic adequacy or ancillary testing yields when comparing the periods 2017-2019 and 2020-2022, despite declining use of ROSE.

CONCLUSIONS

If ROSE is not requested for CT-guided lung biopsies, proceduralists should err on the side of performing more, rather than fewer, passes, particularly for smaller lesions.

Diagnostic yield and complication rates of percutaneous transthoracic CT-guided coaxial needle biopsy in persistent pulmonary consolidation

OBJECTIVES

To investigate the diagnostic performance and complication rates of percutaneous transthoracic CT-guided coaxial core needle biopsy (PTCNB) in persistent consolidations and evaluate its safety in routine clinical practice.

METHODS

A total of 685 patients (404 males, 281 females) underwent PTCNB with coaxial core technique for persisted consolidation were reviewed in this study. According to histopathological and microbiological analysis, the results of biopsy specimens were categorized as follows: malignant, specific benign, non-specific benign and non-diagnostic. The final diagnosis was established through surgical resection or clinicoradiological follow-up for at least 12 months following biopsy. Diagnostic yield of PTCNB was defined as the percentage of the true diagnosis from biopsy as malignant and specific benign lesions.

RESULTS

With respect to the final diagnosis, 54 (54/685; 7.88%) cases were obtained by surgery and the remaining were by follow-up. The total accuracy, sensitivity, specificity of PTCNB for malignancy diagnosis was 94.45%, 84.87%, 100%, respectively. Diagnostic yield of PTCNB was 66.28%. Compared to lesions smaller than 3 cm, higher diagnostic yield (70.89%), lower complication incidence (38.22%) and shorter procedure time (8.78 min) were observed in lesions ≥ 3 cm group.

CONCLUSION

PTCNB in persistent consolidation is a safe and effective procedure, which provide relatively high diagnostic yield and acceptable complication, especially in size over 3 cm lesions.

CRITICAL RELEVANCE STATEMENT

CT-guided coaxial needle biopsy for pulmonary consolidation is a safe and effective procedure. The coaxial needle biopsy yielded high diagnostic rates and low complication rates (including pneumothorax and intrapulmonary hemorrhage), especially in larger lesions.

Computed Tomography (CT)-Guided Needle Biopsy of Lung Lesions: A Single Center Experience

(1) Objective: Lung cancer is one of the leading causes of cancer death among men and women across the globe. The accurate and timely diagnosis of lung lesions is of paramount importance for prognosis. This single-center study is the first to assess the diagnostic yield and complication rate of a computed tomography (CT)-guided needle biopsy of pulmonary parenchymal and pleural nodules in an academic training center in the United States. (2) Methods: This is a retrospective study approved by IRB. Patients who underwent CT-guided needle biopsy between 2016 and 2020 were reviewed. A CT-guided needle biopsy involving mediastinal lesions was excluded, focusing only on lung parenchymal and pleural lesions. A CT-guided needle biopsy aborted at any point during the procedure was also excluded from this study. (3) Results: 1063 patients were included in this study; 532 were males, and 531 were females. Lesion size ranged from 0.26 cm to 9.2 cm. 1040 patients received diagnoses, among which 772 had a specific diagnosis, and 268 had nonspecific inflammatory or non-malignant diagnoses. Twenty-three cases were non-diagnostic. Among the patients with specific diagnoses, 691 were malignant, 5 were hamartomas, 30 were fungal infections, 6 were acid-fast-positive organisms, and 40 were unspecified atypical cells. Of the patients that had a malignant diagnosis, 317 were adenocarcinoma, 197 were squamous cell carcinoma, 26 were a neuroendocrine tumor, 45 were non-small cell carcinoma (undifferentiated), 17 were small cell carcinoma, and 89 were other metastatic malignancies to the lung. Various common complications, including pneumothorax (337), hemorrhage (128), and hemoptysis (17), were observed, and 42 of the cases required chest tube intervention; others were treated with observation. Other rare complications observed included hemothorax (4) and oxygen desaturation (2), and there was no death in this series. (4) Conclusions: CT-guided needle biopsy is a reliable diagnostic modality for patients with lung parenchymal and pleural nodules, and it can effectively distinguish between benign and cancerous lesions before invasive procedures such as video-assisted thoracoscopy (VATs) or thoracotomy are planned. Our study showed a higher rate of pneumothorax and pulmonary hemorrhage compared to the rates established in guidelines, attributable to the varying experience level in a busy training academic center.

Smart goggles augmented reality CT-US fusion compared to conventional fusion navigation for percutaneous needle insertion

PURPOSE

Targeting accuracy determines outcomes for percutaneous needle interventions. Augmented reality (AR) in IR may improve procedural guidance and facilitate access to complex locations. This study aimed to evaluate percutaneous needle placement accuracy using a goggle-based AR system compared to an ultrasound (US)-based fusion navigation system.

METHODS

Six interventional radiologists performed 24 independent needle placements in an anthropomorphic phantom (CIRS 057A) in four needle guidance cohorts (n = 6 each): (1) US-based fusion, (2) goggle-based AR with stereoscopically projected anatomy (AR-overlay), (3) goggle AR without the projection (AR-plain), and (4) CT-guided freehand. US-based fusion included US/CT registration with electromagnetic (EM) needle, transducer, and patient tracking. For AR-overlay, US, EM-tracked needle, stereoscopic anatomical structures and targets were superimposed over the phantom. Needle placement accuracy (distance from needle tip to target center), placement time (from skin puncture to final position), and procedure time (time to completion) were measured.

RESULTS

Mean needle placement accuracy using US-based fusion, AR-overlay, AR-plain, and freehand was 4.5 ± 1.7 mm, 7.0 ± 4.7 mm, 4.7 ± 1.7 mm, and 9.2 ± 5.8 mm, respectively. AR-plain demonstrated comparable accuracy to US-based fusion (p = 0.7) and AR-overlay (p = 0.06). Excluding two outliers, AR-overlay accuracy became 5.9 ± 2.6 mm. US-based fusion had the highest mean placement time (44.3 ± 27.7 s) compared to all navigation cohorts (p < 0.001). Longest procedure times were recorded with AR-overlay (34 ± 10.2 min) compared to AR-plain (22.7 ± 8.6 min, p = 0.09), US-based fusion (19.5 ± 5.6 min, p = 0.02), and freehand (14.8 ± 1.6 min, p = 0.002).

CONCLUSION

Goggle-based AR showed no difference in needle placement accuracy compared to the commercially available US-based fusion navigation platform. Differences in accuracy and procedure times were apparent with different display modes (with/without stereoscopic projections). The AR-based projection of the US and needle trajectory over the body may be a helpful tool to enhance visuospatial orientation. Thus, this study refines the potential role of AR for needle placements, which may serve as a catalyst for informed implementation of AR techniques in IR.

Impact of Respiratory Phase during Pleural Puncture on Complications in CT-Guided Percutaneous Lung Biopsy

Purpose

This study investigated whether the respiratory phase during pleural puncture in CT-guided percutaneous transthoracic needle biopsy (PTNB) affects complications.

Materials and Methods

We conducted a retrospective review of 477 lung biopsy CT scans performed during free breathing. The respiratory phases during pleural puncture were determined based on the table position of the targeted nodule using CT scans obtained during free breathing. We compared the rates of complications among the inspiratory, mid-, and expiratory respiratory phases. Logistic regression analysis was performed to control confounding factors associated with pneumothorax.

Results

Among the 477 procedures, pleural puncture was performed during the expiratory phase in 227 (47.6%), during the mid-phase in 108 (22.6%), and during the inspiratory phase in 142 (29.8%). The incidence of pneumothorax was significantly lower in the expiratory puncture group (40/227, 17.6%; p = 0.035) and significantly higher in the mid-phase puncture group (31/108, 28.7%; p = 0.048). After controlling for confounding factors, expiratory-phase puncture was found to be an independent protective factor against pneumothorax (odds ratio = 0.571; 95% confidence interval = 0.360-0.906; p = 0.017).

Conclusion

Our findings suggest that pleural puncture during the expiratory phase may reduce the risk of pneumothorax during image guided PTNB.

Computed tomography-guided percutaneous needle biopsy for middle mediastinal tumors with retroaortic paravertebral approach: A case report

A 74-year-old man was referred to our hospital for a close examination of a mediastinal mass. Contrast-enhanced CT showed a middle mediastinal tumor. We planned to perform a CT-guided percutaneous needle biopsy of the tumor using a retroaortic paravertebral approach to avoid transpulmonary puncture. A coaxial blunt-tip needle with a side hole was used to create space in the mediastinum and avoid azygos vein injury. After injecting normal saline, a blunt-tip needle was advanced through the space between the aorta and the vertebral body to the anterior surface of the tumor, and tissue was obtained. The patient was discharged the following day with no complications. For percutaneous middle mediastinal tumor biopsy, the retroaortic paravertebral approach may be a safe, effective route.

Safety profile and technical success of narrow window CT-guided percutaneous biopsy with blunt needle approach in the abdomen and pelvis

OBJECTIVE

To assess success and safety of CT-guided procedures with narrow window access for biopsy.

METHODS

Three hundred ninety-six consecutive patients undergoing abdominal or pelvic CT-guided biopsy or fiducial placement between 01/2015 and 12/2018 were included (183 women, mean age 63 ± 14 years). Procedures were classified into "wide window" (width of the needle path between structures > 15 mm) and "narrow window" (≤ 15 mm) based on intraprocedural images. Clinical information, complications, technical and clinical success, and outcomes were collected. The blunt needle approach is preferred by our interventional radiology team for narrow window access.

RESULTS

There were 323 (81.5%) wide window procedures and 73 (18.5%) narrow window procedures with blunt needle approach. The median depth for the narrow window group was greater (97 mm, interquartile range (IQR) 82-113 mm) compared to the wide window group (84 mm, IQR 60-106 mm); p = 0.0017. Technical success was reached in 100% (73/73) of the narrow window and 99.7% (322/323) of the wide window procedures. There was no difference in clinical success rate between the two groups (narrow: 86.4%, 57/66; wide: 89.5%, 265/296; p = 0.46). There was no difference in immediate complication rate (narrow: 1.3%, 1/73; wide: 1.2%, 4/323; p = 0.73) or delayed complication rate (narrow: 1.3%, 1/73; wide: 0.6%, 1/323; p = 0.50).

CONCLUSION

Narrow window (< 15 mm) access biopsy and fiducial placement with blunt needle approach under CT guidance is safe and successful.

CLINICAL RELEVANCE STATEMENT

CT-guided biopsy and fiducial placement can be performed through narrow window access of less than 15 mm utilizing the blunt-tip technique.

KEY POINTS

• A narrow window for CT-guided abdominal and pelvic biopsies and fiducial placements was considered when width of the needle path between vital structures was ≤ 15 mm. • Seventy-three biopsies and fiducial placements performed through a narrow window with blunt needle approach had a similar rate of technical and clinical success and complications compared to 323 procedures performed through a wide window approach, with traditional approach (> 15 mm). • This study confirmed the safety of the CT-guided percutaneous procedures through < 15 mm window with blunt-tip technique.

The Impact of Rapid On-site Evaluation on Diagnostic Performance of Computed Tomography-Guided Core Needle Biopsy in Lung Cancer

PURPOSE

Rapid on-site-evaluation (ROSE) is a technique aimed at improving the diagnostic performance of computed tomography (CT)-guided core needle biopsy (CNB) in lung cancer. The aim of this retrospective study was to investigate the impact of ROSE on the rate of nondiagnostic specimens and on accuracy computed on diagnostic specimens.

MATERIALS AND METHODS

During a 3-year period, 417 CT-guided CNBs were performed at our center. The biopsies were retrospectively classified into 2 groups: 141 procedures were assisted by ROSE and 276 were not. All of them were reviewed for clinical, procedural, and pathological data. Pathology results were classified as diagnostic (positive or negative for malignancy) or nondiagnostic. The results were compared with the final diagnosis after surgery or clinical follow-up. Nondiagnostic rate, sensitivity/specificity/negative predictive value/positive predictive value for the ROSE and non-ROSE groups were calculated. Finally, procedural complications and the adequacy of the specimens for the molecular analysis were recorded.

RESULTS

The study evaluated 417 CNBs (mean patients' age 71 years, 278 men). Nondiagnostic rates with and without ROSE were 4% (6/142) and 11% (29/276), respectively (P = 0.028). Sensitivity/specificity/negative predictive value/positive predictive value with and without ROSE did not show statistically significant differences, and no difference in major/minor complication rates was observed between the 2 groups. The adequacy of specimen for subsequent molecular analysis was 100% with (42/42) and 82% without ROSE (51/62).

CONCLUSIONS

Rapid on-site-evaluation reduced the rate of nondiagnostic specimens by 50% with no change in complication rates or accuracy and increased by 20% the chances of a successful subsequent molecular analysis.

CT-Guided Trans-osseous Biopsy: Experience in 24 Patients

PURPOSE

The objective of this study is to assess the effectiveness of computed tomography-guided trans-osseous biopsies in deep-seated lesions and report encountered complications.

MATERIALS AND METHODS

A retrospective cohort study was performed which included twenty-four patients with pathologic medical history and lesions non-accessible by common approaches. Exclusion criteria include patients who could be biopsied without trans-osseous access, as for example procedures aided with hydro- or pneumo-dissection. The population studied included 13 females (54.2%) and the overall average age was 64.5 (IIQ 43-69). The procedures were carried out through the following bones: sternum (n = 6), vertebral (n = 5), iliac (n = 5), scapula (n = 3), rib (n = 2), sacral (n = 2), and pubis (n = 1).

RESULTS

The efficiency for these procedures was 87.5%, while 8.33% of them were non-diagnostic and 4.17% were inconclusive due to vital risk during the procedure.

CONCLUSION

Computed tomography-guided trans-osseous biopsy resulted in a safe and effective technique for those lesions blocked by vital structures or apparently directly inaccessible.

[Ultrasound guided biopsy of lung tumors: evaluation of efficacy and complications]

Introduction

The diagnosis of lung cancer, as well as that of lung nodules, is increasing. Percutaneous biopsy has become a transcendental tool for its diagnosis. Traditionally, computed tomography is used for these procedures because of its ability to clearly demonstrate bone and aerated lung. However, in selected cases it can be performed with ultrasound.

Methods

Retrospective study conducted between January 2020 and December 2021, during the SARS-CoV-2 pandemic. All patients had pleural-based lung lesions or pleural lesions, some with a known history of cancer.

Results

Thirty-six procedures were performed, in 32 (88.9%) the sample obtained presented diagnostic yield and the most used additional test was Immunohistochemistry in 23 (63.9%). Complications were reported in 5 patients (13.9%): 2 with mild pneumothorax, 2 with hemothorax (1 mild and 1 moderate) and 1 patient reported pain.

Conclusion

Ultrasound is a valid method to be used as a guide for biopsies of pleural and peripheral pulmonary lesions. The complications and diagnostic rate has been shown to be in line with the experience of other authors and international guidelines.

Percutaneous core-needle biopsy before and immediately after coaxial microwave ablation in solid non-small cell lung cancer: the comparison of genomic testing from specimens

PURPOSE

To compare the genomic testing based on specimens obtained from percutaneous core-needle biopsy (CNB) before and immediately after coaxial microwave ablation (MWA) in solid non-small cell lung cancer (NSCLC), and to investigate the diagnostic performance of CNB immediately after coaxial MWA in solid NSCLC.

METHODS

Coaxial MWA and CNB were performed for NSCLC patients, with a power of 30 or 40 watts (W) in MWA between the pre- and post-ablation CNB, followed by continuous ablation after the second CNB on demand. The paired specimens derived from the same patient were compared for pathological diagnosis and genomic testing. DNA/RNA extracted from the paired specimens were also compared.

RESULTS

A total of 33 NSCLC patients with solid lesions were included. There were two patients (6.1%) without atypical cells and three patients (9.1%) who had the technical failure of genomic testing in post-ablation CNB. The concordance rate of pathological diagnosis between the twice CNB was 93.9% (kappa = 0.852), while that of genomic testing was 90.9% (kappa = 0.891). For the comparisons of DNA/RNA extracted from pre- and post-ablation CNB in 30 patients, no significant difference was found when the MWA between twice CNB has a power of 30 or 40 W and ablation time within five minutes (P = 0.174).

CONCLUSIONS

If the pre-ablation CNB presented with a high risk of pneumothorax or hemorrhage, the post-ablation CNB could be performed to achieve accurate pathological diagnosis and genomic testing and the maximum effect of ablation, which might allow for the diagnosis of genomic testing in 90.9% of solid NSCLC.

An overview of interventional radiology techniques for the diagnosis and management of vascular anomalies: Part 2

Minimally invasive percutaneous and endovascular strategies performed by interventional radiologists have become the mainstays of treatment for vascular anomalies with improved outcomes, decreased complication rates, and less morbidity. The aim of this article is to introduce physicians who care for patients with vascular anomalies to state-of-the-art advancements in interventional radiology for diagnosis and treatment. Part 2 of this review discusses embolization, endovenous laser ablation, and image-guided percutaneous biopsy. Please see Part 1 for a discussion of sclerotherapy and cryoablation. Select vascular anomalies will be discussed as examples to highlight IR diagnostic and/or treatment techniques.

Effect of the respiratory motion of pulmonary nodules on CT-guided percutaneous transthoracic needle biopsy

BACKGROUND

Computed tomography (CT)-guided percutaneous transthoracic needle biopsy (PTNB) is highly affected by respiratory motion; however, respiratory motion of target nodule during the PTNB and its effect on CT-guided lung biopsy have not been studied.

PURPOSE

To investigate the effect of the respiratory motion of pulmonary nodules on CT-guided PTNB.

MATERIAL AND METHODS

We retrospectively reviewed the procedural CT scans of 426 pulmonary nodules that underwent PTNB during quiet breathing. Maximal and average respiratory motions were measured using the difference of table position of the targeted nodule between multiple procedural scans. Diagnostic performance, complications, and technical factors of PTNB in nodules with large motion (maximal motion >1 cm) were compared with those in nodules with small motion (≤1 cm).

RESULTS

The mean maximal and average respiratory motions between tidal volume breathing were 5.4 ± 4.4 and 2.7 ± 2.6 mm, respectively. Sensitivity and accuracy were 93.1% and 96.1% in nodules with large motion, compared with 94.7% and 95.9% in nodules with small motion, respectively. Respiratory targeting (P < 0.001), needle modulation (P < 0.001), motion artifact of target (P < 0.001), target disappearance from scans (P < 0.001), and number of performed CT scans (P < 0.001) were significantly higher in the large motion group, with no significant difference in radiation dose and complications between the groups.

CONCLUSION

The respiratory motion of pulmonary nodules during CT-guided PTNB may cause technical difficulties but does not affect diagnostic performance nor complications associated with PTNB.

Current Practices in Anticoagulation Management for Patients Undergoing Percutaneous Image-guided Breast Procedures

Objective

Given variability in how practices manage patients on antithrombotic medications, we undertook this study to understand the current practice of antithrombotic management for patients undergoing percutaneous breast and axillary procedures.

Methods

A 20-item survey with multiple-choice and write-in options was emailed to 2094 active North American members of the Society of Breast Imaging (SBI) in March 2021. Data were collected anonymously and analyzed quantitatively, with free-text responses categorized by themes.

Results

Three-hundred twenty-six of 2094 members (15.6%) completed the survey. Eighty-seven percent (274/313) reported having a policy for managing antithrombotic medications. Fifty-nine percent (185/312) reported routinely withholding medications before biopsy, more commonly in the Northeast and South (P = 0.08). Withholding of medications did not vary by lesion location (182/308, 59%, breast vs 181/308, 58.7%, axillary; P = 0.81). Respondents were statistically more likely to withhold medications if using a vacuum-assisted device for all classes of antithrombotic medications (P < 0.001). Up to 50.2% (100/199) on warfarin and 33.6% (66/196) on direct oral anticoagulants had medications withheld more stringently than guidelines suggest.

Conclusion

Based on a survey of SBI members, breast imaging practices vary widely in antithrombotic management for image-guided breast and axillary procedures. Of the 60% who withhold antithrombotic medications, a minority comply with recommended withhold guidelines, placing at least some patients at potential risk for thrombotic events. Breast imaging radiologists should weigh the risks and benefits of withholding these medications, and if they elect to withhold should closely follow evidence-based guidelines to minimize the risks of this practice.

Comparison between percutaneous transthoracic co-axial needle CT-guided biopsy and transbronchial lung biopsy for the diagnosis of persistent pulmonary consolidation

BACKGROUND

Diagnosing persistent pulmonary consolidation still faces challenges. The purpose of this study is to compare the diagnostic yield and the complication rate between percutaneous transthoracic CT-guided coaxial needle biopsy (PTCNB) and transbronchial lung biopsy (TBLB) of persistent pulmonary consolidation.

MATERIALS

From January 1, 2016, to December 31, 2020, we have retrospectively enrolled a total of 155 consecutive patients (95 males, 60 females) with persistent pulmonary consolidation who underwent both TBLB and PTCNB. According to the standard reference, the diagnostic yield, accuracy, sensitivity and specificity of PTCNB and TBLB were assessed and compared.

RESULTS

According to the standard reference, the final biopsy diagnoses of 11 cases were confirmed true malignant based on the surgical resections, the remaining were confirmed by clinical and imaging follow-up for at least 12 months. The overall diagnostic accuracy, sensitivity and specificity of PTCNB for malignant diagnosis were 91.61%, 72.34% and 100%, whereas of TBLB were 87.74%, 59.57% and 100%. The diagnostic yield of PTCNB and TBLB were 50.32% and 25.16%, respectively. For the TBLB-based negative cases, PTCNB provided a definite diagnostic yield of 37.93%. There were 45 (29.03%), 22 (14.19%) and 13 (8.39%) patients who experienced pneumothorax, intrapulmonary hemorrhage and hemoptysis, respectively, in PTCNB, while there were only 5 (3.22%) cases of mild intraprocedural bleeding occurring in TBLB.

CONCLUSIONS

CT-guided co-axial needle biopsy is an effective and safe modality, associated with higher diagnostic yield and better diagnostic accuracy compared to transbronchial lung biopsy for malignancy presenting as persistent consolidation, especially as the complementary method for TBLB-based negative lung lesions.

KEY POINTS

Both PTCNB and TBLB showed high diagnostic accuracy for malignancy. PTCNB had a higher diagnostic yield than TBLB for persistent pulmonary consolidation. PTCNB could provide a complementary diagnosis for TBLB-based negative lung consolidation.

Percutaneous CT-Guided Abdominal and Pelvic Biopsies: Comparison of an Electromagnetic Navigation System and CT Fluoroscopy

PURPOSE

To compare electromagnetic navigation (EMN) with computed tomography (CT) fluoroscopy for guiding percutaneous biopsies in the abdomen and pelvis.

MATERIALS AND METHODS

A retrospective matched-cohort design was used to compare biopsies in the abdomen and pelvis performed with EMN (consecutive cases, n = 50; CT-Navigation; Imactis, Saint-Martin-d'Hères, France) with those performed with CT fluoroscopy (n = 100). Cases were matched 1:2 (EMN:CT fluoroscopy) for target organ and lesion size (±10 mm).

RESULTS

The population was well-matched (age, 65 vs 65 years; target size, 2.0 vs 2.1 cm; skin-to-target distance, 11.4 vs 10.7 cm; P > .05, EMN vs CT fluoroscopy, respectively). Technical success (98% vs 100%), diagnostic yield (98% vs 95%), adverse events (2% vs 5%), and procedure time (33 minutes vs 31 minutes) were not statistically different (P > .05). Operator radiation dose was less with EMN than with CT fluoroscopy (0.04 vs 1.2 μGy; P < .001), but patient dose was greater (30.1 vs 9.6 mSv; P < .001) owing to more helical scans during EMN guidance (3.9 vs 2.1; P < .001). CT fluoroscopy was performed with a mean of 29.7 tap scans per case. In 3 (3%) cases, CT fluoroscopy was performed with gantry tilt, and the mean angle out of plane for EMN cases was 13.4°.

CONCLUSIONS

Percutaneous biopsies guided by EMN and CT fluoroscopy were closely matched for technical success, diagnostic yield, procedure time, and adverse events in a matched cohort of patients. EMN cases were more likely to be performed outside of the gantry plane. Radiation dose to the operator was higher with CT fluoroscopy, and patient radiation dose was higher with EMN. Further study with a wider array of procedures and anatomic locations is warranted.

The Contemporary Landscape and Future Directions of Intratumoral Immunotherapy

Systemically administered immunotherapies have revolutionized the care of patients with cancer; however, for many cancer types, most patients do not exhibit objective responses. Intratumoral immunotherapy is a burgeoning strategy that is designed to boost the effectiveness of cancer immunotherapies across the spectrum of malignancies. By locally administering immune-activating therapies into the tumor itself, immunosuppressive barriers in the tumor microenvironment can be broken. Moreover, therapies too potent for systemic delivery can be safely administered to target location to maximize efficacy and minimize toxicity. In order for these therapies to be effective, though, they must be effectively delivered into the target tumor lesion. In this review, we summarize the current landscape of intratumoral immunotherapies and highlight key concepts that influence intratumoral delivery, and by extension, efficacy. We also provide an overview of the breadth and depth of approved minimally invasive delivery devices that can be considered to improve delivery of intratumoral therapies.

Prediction of Complication Risk in Computed Tomography-guided Thoracic Biopsy: A Prescription for Improving Procedure Safety

PURPOSE

Computed tomography-guided transthoracic biopsy (CTTB) is a minimally invasive procedure with a high diagnostic yield for a variety of thoracic diseases. We comprehensively assessed a large CTTB cohort to predict procedural and patient factors associated with the risk of complications.

MATERIALS AND METHODS

The medical record and computed tomography images of 1430 patients who underwent CTTB were reviewed individually to obtain clinical information and technical procedure factors. Statistical analyses included descriptive and summary statistics, univariate analysis with the Fisher test, and multivariate logistic regression.

RESULTS

The most common type of complication was pneumothorax (17.4%), followed by bleeding (5.9%). Only 26 patients (1.8%) developed a major complication. Lung lesions carried a higher risk of complications than nonlung lesions. For lung lesions, the nondependent position of the lesion, vertical needle approach, trespassing aerated lung, and involvement of a trainee increased the risk of complication, whereas the use of the coaxial technique was a protective factor. The time with the needle in the lung, the number of biopsy samples, and the distance crossing the aerated lung were identified as additional risk factors in multivariate analysis. For nonlung lesions, trespassing the pleural space was the single best predictor of complications. A logistic regression-based model achieved an area under the receiver operating characteristic curve of 0.975, 0.699, and 0.722 for the prediction of major, minor, and no complications, respectively.

CONCLUSIONS

Technical procedural factors that can be modified by the operator are highly predictive of the risk of complications in CTTB.

Intravascular Ultrasound-Guided Transvenous Biopsy of Retroperitoneal Lymph Nodes: Diagnostic Accuracy and Safety Compared with CT-Guided Percutaneous Biopsy

PURPOSE

To compare the diagnostic accuracy and adverse event rates of intravascular ultrasound (US)-guided transvenous biopsy (TVB) versus those of computed tomography (CT)-guided percutaneous needle biopsy (PNB) for retroperitoneal (RP) lymph nodes.

MATERIALS AND METHODS

In this single-institution, retrospective study, 32 intravascular US-guided TVB procedures and a sample of 34 CT-guided PNB procedures for RP lymph nodes where targets were deemed amenable to intravascular US-guided TVB were analyzed. Procedural metrics, including diagnostic accuracy, defined as diagnostic of malignancy or a clinically verifiable benign result, and adverse event rates were compared.

RESULTS

The targets of intravascular US-guided TVB were primarily aortocaval (47%, 15/32) or precaval (34%, 11/32), whereas those of CT-guided PNB were primarily right pericaval (44%, 15/34) or retrocaval (44%, 15/34) (P < .001). The targets of intravascular US-guided TVB averaged 2.4 cm in the long axis (range, 1.3-3.7 cm) compared with 2.9 cm (range, 1.4-5.7 cm) for those of CT-guided PNB (P = .02). There was no difference in the average number of needle passes (3.8 for intravascular US-guided TVB vs 3.9 for CT-guided PNB; P = .68). The diagnostic accuracy was 94% (30/32) and the adverse event rate was 3.1% (1/32) for intravascular US-guided TVB, similar to those of CT-guided PNB (accuracy, 91% [31/34]; adverse event rate, 2.9% [1/34]).

CONCLUSIONS

Intravascular US-guided TVB had a diagnostic accuracy and adverse event rate similar to CT-guided PNB for RP lymph nodes, indicating that intravascular US-guided TVB may be as safe and effective as conventional biopsy approaches for appropriately selected targets.

Role of Interventional Radiology in Pediatric Cancer Patients

PURPOSE OF REVIEW

Pediatric interventional radiology (IR) is a growing subspecialty. Here, we review the current role of IR in children with cancer, which uses imaging such as ultrasound, fluoroscopy, and computed tomography to perform minimally invasive procedures. These include biopsy, needle localization, central venous access, thermal ablation, transarterial chemoembolization, transarterial radioembolization with yttrium-90, non-tunneled/tunneled drainage catheter placement, and lymphatic interventions.

RECENT FINDINGS

Although locoregional therapies for the treatment of cancer in adults are common, they are less common in children, perhaps due to the relative rarity of cancer in children, their typically better performance status, and paucity of comorbidities. Preliminary results from small-scale studies for ablation, transarterial chemoembolization, and transarterial radioembolization with yttrium-90 used in the front-line armamentarium of curative therapy are encouraging. Pediatric IR offers an array of minimally invasive procedures intended to diagnose and treat pediatric cancer patients. However, more research is required to determine the efficacy of locoregional therapy in children and to define the clinical scenarios where benefit is likely to be optimized.

Percutaneous ultrasound-guided renal biopsies in a paediatric population: comparison of coaxial and non-coaxial techniques using 18-gauge core biopsy needles

BACKGROUND

Percutaneous ultrasound-guided biopsy is performed in paediatric patients for evaluation of diffuse renal parenchymal disease. When compared with the non-coaxial technique, the coaxial technique has the advantages of obtaining multiple tissue cores via a single capsular puncture and post-biopsy tract embolisation.

OBJECTIVES

To compare the coaxial and non-coaxial techniques of percutaneous ultrasound (US)-guided biopsy of native kidney parenchyma in children and adolescents with renal disease.

MATERIALS AND METHODS

We retrospectively identified consecutive patients who underwent percutaneous US-guided renal biopsy using an 18-gauge core biopsy needle from July 2019 to July 2021 in a single tertiary paediatric nephrology centre. Focal renal tumour biopsy and transplant kidney biopsy were excluded. The total glomerular yield, specimen adequacy, complication rate and procedural time between the coaxial and non-coaxial groups were compared.

RESULTS

There were 34 percutaneous US-guided renal biopsies: 22 using a coaxial technique and 12 using a non-coaxial technique. The total median glomerular yield obtained was higher in the coaxial group (coaxial=37.9; non-coaxial=22.2; P=0.02). No statistically significant difference was noted between specimen adequacy (coaxial=100%; non-coaxial=91.7%; P=0.35). While no statistically significant difference was detected for overall complication rates (coaxial=13.6%; non-coaxial=41.7%; P=0.09), the coaxial group had a lower rate of haemorrhagic complications (coaxial=4.5%; non-coaxial=41.7%; P=0.01). One patient in the non-coaxial group had post-biopsy haemorrhage requiring embolisation. The procedural time was shorter in the coaxial group (coaxial=26.3 ± 7.0 min; non-coaxial=51.3 ± 11.5 min; P&lt;0.001).

CONCLUSION

Percutaneous US-guided renal biopsy in children using the coaxial technique has significantly higher total glomerular yield, shorter procedural time and fewer haemorrhagic complications, compared to biopsies using the non-coaxial technique.

An Expert, Multidisciplinary Perspective on Best Practices in Biomarker Testing in Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCCA) is a rare and aggressive malignancy that arises from the intrahepatic biliary tree and is associated with a poor prognosis. Until recently, the treatment landscape of advanced/metastatic iCCA has been limited primarily to chemotherapy. In recent years, the advent of biomarker testing has identified actionable genetic alterations in 40%-50% of patients with iCCA, heralding an era of precision medicine for these patients. Biomarker testing using next-generation sequencing (NGS) has since become increasingly relevant in iCCA; however, several challenges and gaps in standard image-guided liver biopsy and processing have been identified. These include variability in tissue acquisition relating to the imaging modality used for biopsy guidance, the biopsy method used, number of passes, needle choice, specimen preparation methods, the desmoplastic nature of the tumor, as well as the lack of communication among the multidisciplinary team. Recognizing these challenges and the lack of evidence-based guidelines for biomarker testing in iCCA, a multidisciplinary team of experts including interventional oncologists, a gastroenterologist, medical oncologists, and pathologists suggest best practices for optimizing tissue collection and biomarker testing in iCCA.

Canadian Association of Radiologists/Canadian Association of Interventional Radiologists/Canadian Society of Thoracic Radiology Guidelines on Thoracic Interventions

Thoracic interventions are frequently performed by radiologists, but guidelines on appropriateness criteria and technical considerations to ensure patient safety regarding such interventions is lacking. These guidelines, developed by the Canadian Association of Radiologists, Canadian Association of Interventional Radiologists and Canadian Society of Thoracic Radiology focus on the interventions commonly performed by thoracic radiologists. They provide evidence-based recommendations and expert consensus informed best practices for patient preparation; biopsies of the lung, mediastinum, pleura and chest wall; thoracentesis; pre-operative lung nodule localization; and potential complications and their management.

Safety of image guided research biopsies in patients with thoracic malignancies

OBJECTIVE

A common opportunity to collect research samples is during image-guided percutaneous core needle biopsies (CNBs) performed when clinically indicated or for assessing clinical trial eligibility. The relative safety of extra CNBs collected for research is undefined.

MATERIALS AND METHODS

Patients who underwent CNB for research purposes only [RO], as clinically indicated [CI], or as part of a clinical trial [CT] were identified. 30-day post-procedure adverse events (AEs) among the cohorts were examined and compared to the 2020 Society of Interventional Radiology QI guidelines.

RESULTS

236 patients with thoracic cancers (90 % NSCLC, 5 % SCLC, 4 % mesothelioma, and 1 % thymic) had 292 CNBs (63 RO, 229 CI + CT). AEs occurred in 13 % of both the RO and CI + CT groups. Compared to the CI + CT group, the RO group did not have a higher pneumothorax incidence (RO: 5/29 [17 %], CI + CT: 18/114 [16 %], p = 0.79); both were below the suggested QI threshold of 45 % for pneumothorax. There was a negative association between number of cores obtained and risk of AE (AE vs no AE mean cores = 3.5 vs 4.8). After adjusting for the number of cores and smoking history, RO vs CI + CT lung biopsies had a higher risk of AEs (adjusted relative risk [aRR] = 2.44, 1.08-5.55, p = 0.03 vs non-lung aRR = 0.86, 0.10-7.09, p = 0.89).

CONCLUSION

CNBs performed for research purposes do not have a significantly increased risk of AEs when compared to those performed for clinical trials and/or when clinically indicated. However, AEs were most frequent in lung biopsies. When performing research biopsies, a target other than lung may be preferred when clinically appropriate.

Techniques for Profiling the Cellular Immune Response and Their Implications for Interventional Oncology

In recent years there has been increased interest in using the immune contexture of the primary tumors to predict the patient's prognosis. The tumor microenvironment of patients with cancers consists of different types of lymphocytes, tumor-infiltrating leukocytes, dendritic cells, and others. Different technologies can be used for the evaluation of the tumor microenvironment, all of which require a tissue or cell sample. Image-guided tissue sampling is a cornerstone in the diagnosis, stratification, and longitudinal evaluation of therapeutic efficacy for cancer patients receiving immunotherapies. Therefore, interventional radiologists (IRs) play an essential role in the evaluation of patients treated with systemically administered immunotherapies. This review provides a detailed description of different technologies used for immune assessment and analysis of the data collected from the use of these technologies. The detailed approach provided herein is intended to provide the reader with the knowledge necessary to not only interpret studies containing such data but also design and apply these tools for clinical practice and future research studies.

Liquid biopsy assay for pulmonary adenocarcinoma using supernatants from core‐needle biopsy specimens

Background

Genomic testing is the cornerstone of the treatment of patients with non‐small‐cell lung cancer. However, comprehensive molecular testing of small specimens may be inadequate due to limited tissue. Liquid biopsy has emerged as a new method of genotyping. In this study, we evaluate the feasibility of using supernatants from core needle biopsy samples of lung adenocarcinoma for genomic testing.

Methods

Core needle biopsy specimens and their supernatants were collected from patients (n = 48) with lung adenocarcinoma. Genomic testing results of the supernatant samples were compared with results derived from paired tissue samples from the same patient.

Result

All 48 supernatant samples yield adequate cell‐free DNA, but the concentration of cell‐free RNA did not meet the criteria for analysis. The concordance rate between the genomic testing results of supernatants and the corresponding tissue samples was 95.8% (kappa = 0.899). The coincidence rate of detectable mutations at the DNA level in the supernatants was up to 100%.

Conclusion

Core needle biopsy supernatants can provide a valuable specimen source for genotyping pulmonary adenocarcinoma. However, the method of preserving and extracting RNA from supernatant specimens needs further improvement.

Role of Image-Guided Percutaneous Needle Biopsy in the Age of Precision Medicine

PURPOSE OF REVIEW

With the remarkable progress in cancer precision medicine, the demand for biopsy has been increasing, and the role of biopsy has been changing. In this review, we discuss the current state and recent advances in the role of image-guided percutaneous needle biopsy (PNB) in facilitating precision medicine.

RECENT FINDINGS

Biopsies are useful not only in the diagnosis of cancer and histological sub-type but also in the analysis of its molecular characteristics for targeted treatments. PNB specimens have been shown to provide high DNA yields for genomic analysis. Liquid biopsy is an emerging technology but is under development; therefore, PNB is the current standard of practice and is performed complimentarily with liquid biopsy. In the age of precision medicine, interventional oncologists play a key role in optimal tissue collection for adequate genomic analysis. Effective PNB may improve its diagnostic utility and help optimize precision medicine.

Preoperative CT-guided Fiducial Marker Placement for Surgical Localization of Pulmonary Nodules

PURPOSE

To assess the technical success and complication rates of CT-guided fiducial marker placement for the localization of pulmonary nodules and to assess the surgical localization failure rate.

MATERIALS AND METHODS

This was a single-center, retrospective analysis of consecutive patients who underwent CT-guided fiducial marker placement procedures between 2014 and 2020. End points included the technical success of the fiducial marker placement, procedural complications, and the surgical localization failure rate. A two-sample t test and a Fisher exact test were used to compare continuous and categorical variables, respectively. Multivariate logistic regression was used to identify independent risk factors for complications.

RESULTS

A total of 198 preoperative CT-guided fiducial marker placement procedures were performed in 190 patients (mean age, 64 years ± 12 [standard deviation]; 121 women) to localize 205 nodules (mean size, 10 mm ± 4; mean distance to the pleura, 10 mm ± 9). The technical success rate was 98.5% (195 of 198). There were no major complications. A total of 202 nodules were resected during 193 procedures performed 5 days ± 13 after the fiducial marker placement (range, 0-123 days). Surgical localization failure occurred in one patient (0.5%). Of the resected nodules, 146 were lung cancers, 26 nodules were metastases, two were carcinoid tumors, and 28 were benign.

CONCLUSION

The CT-guided fiducial marker placement of pulmonary nodules was safe, effective, and resulted in a low surgical localization failure rate.Keywords: CT, Percutaneous, Thorax, Lung.

Optimizing the Diagnosis and Biomarker Testing for Patients with Intrahepatic Cholangiocarcinoma: A Multidisciplinary Approach

Cholangiocarcinoma (CCA) is a heterogenous group of malignancies originating in the biliary tree, and associated with poor prognosis. Until recently, treatment options have been limited to surgical resection, liver-directed therapies, and chemotherapy. Identification of actionable genomic alterations with biomarker testing has revolutionized the treatment paradigm for these patients. However, several challenges exist to the seamless adoption of precision medicine in patients with CCA, relating to a lack of awareness of the importance of biomarker testing, hurdles in tissue acquisition, and ineffective collaboration among the multidisciplinary team (MDT). To identify gaps in standard practices and define best practices, multidisciplinary hepatobiliary teams from the University of California (UC) Davis and UC Irvine were convened; discussions of the meeting, including optimal approaches to tissue acquisition for diagnosis and biomarker testing, communication among academic and community healthcare teams, and physician education regarding biomarker testing, are summarized in this review.

Image-guided Percutaneous Biopsy of the Liver

Percutaneous Biopsy of the Liver (PBL) is a cornerstone in the diagnosis of parenchymal liver disease and focal hepatic lesions. The indications for PBL can broadly be divided into those used to garner information regarding diagnosis, prognosis, or treatment. While the diagnosis of many common liver diseases can usually be made with imaging and serologic testing alone, PBL may be indicated in situations where the diagnosis is in question. Furthermore, liver biopsies are a foundational element for personalized treatment approaches for cancer patients; increasing emphasis is being placed on acquiring sufficient tissue for molecular profiling. While a variety of image guidance and procedural techniques have been applied to PBL, following conventional principles can ensure technical success and minimize complication risks. In this technique article, we review the practical periprocedural considerations of PBL with emphasis on recent advancements and societal recommendations.

Transvenous Biopsies - Technique, Pearls, and Pitfalls

Image-guided biopsies are one of the most common requests received by radiologists, and while most are straightforward, some lesions are not amenable to percutaneous sampling due to location or depth. Advances in intravascular ultrasound combined with the principles of non-targeted transvenous solid organ biopsy allow for direct visualization and successful targeted transvenous biopsies of solid organ and perivascular lesions. Here, we present our technique and three example cases of transvenous biopsies.

Percutaneous Core Needle Biopsy: Considerations in the Pediatric Patient

Image-guided percutaneous biopsy is the cornerstone of solid tissue diagnosis. The ability to safely sample tissue in locations that previously required surgery or necessitated empiric therapy has allowed for more personalized treatment options, as well as more rapid development of novel therapeutics. In children, these same advantages are accompanied by a smaller margin for error and rapidly expanding indications. The intent of this review is to outline the role of image-guided biopsy in the management of childhood disease, how this role is changing, and the practical aspects of managing and performing pediatric biopsies.

Variability in biopsy quality informs translational research applications in hepatocellular carcinoma

In the era of precision medicine, biopsies are playing an increasingly central role in cancer research and treatment paradigms; however, patient outcomes and analyses of biopsy quality, as well as impact on downstream clinical and research applications, remain underreported. Herein, we report biopsy safety and quality outcomes for percutaneous core biopsies of hepatocellular carcinoma (HCC) performed as part of a prospective clinical trial. Patients with a clinical diagnosis of HCC were enrolled in a prospective cohort study for the genetic, proteomic, and metabolomic profiling of HCC at two academic medical centers from April 2016 to July 2020. Under image guidance, 18G core biopsies were obtained using coaxial technique at the time of locoregional therapy. The primary outcome was biopsy quality, defined as tumor fraction in the core biopsy. 56 HCC lesions from 50 patients underwent 60 biopsy events with a median of 8 core biopsies per procedure (interquartile range, IQR, 7–10). Malignancy was identified in 45/56 (80.4%, 4 without pathology) biopsy events, including HCC (40/56, 71.4%) and cholangiocarcinoma (CCA) or combined HCC-CCA (5/56, 8.9%). Biopsy quality was highly variable with a median of 40% tumor in each biopsy core (IQR 10–75). Only 43/56 (76.8%) and 23/56 (41.1%) samples met quality thresholds for genomic or metabolomic/proteomic profiling, respectively, requiring expansion of the clinical trial. Overall and major complication rates were 5/60 (8.3%) and 3/60 (5.0%), respectively. Despite uniform biopsy protocol, biopsy quality varied widely with up to 59% of samples to be inadequate for intended purpose. This finding has important consequences for clinical trial design and highlights the need for quality control prior to applications in which the presence of benign cell types may substantially alter findings.

An analysis of research biopsy core variability from over 5000 prospectively collected core samples

Factors correlated with biopsy tissue adequacy and the prevalence of within-biopsy variability were evaluated. Totally, 1149 research biopsies were performed on 686 patients from which 5090 cores were assessed. Biopsy cores were reviewed for malignant percentage (estimated percentage of cells in the core that were malignant) and malignant area (estimated area occupied by malignant cells). Linear mixed models and generalized linear mixed models were used for the analysis. A total of 641 (55.8%) biopsies contained a core with <10% malignant percentage (inadequate core). The chance of an inadequate core was not influenced by core order, though the malignant area decreased with each consecutive core (p < 0.001). Younger age, bone biopsy location, appendiceal tumor pathology, and responding/stable disease prior to biopsy increased the odds of a biopsy containing zero adequate cores. Within-biopsy variability in core adequacy is prevalent and suggests the need for histological tumor quality assessment of each core in order to optimize translational analyses.

Learning Curve for CT-Guided Percutaneous Transthoracic Core Needle Biopsy: Retrospective Evaluation Among 17 Thoracic Imaging Fellows at a Tertiary Referral Hospital

To listen to the podcast associated with this article, please select one of the following: iTunes, Google Play, or direct download. Background: CT-guided percutaneous transthoracic needle biopsy (PTNB) is widely used for evaluation of indeterminate pulmonary lesions, though guidelines are lacking regarding the experience needed to gain sufficient skill. Objective: To investigate the learning curve among a large number of operators in a tertiary referral hospital and to determine the number of procedures required to obtain acceptable performance. Methods: This retrospective study included CT-guided PTNBs with coaxial technique performed by 17 thoracic imaging fellows from March 2011 to August 2017 who were novices in the procedure. A maximum of 200 consecutive procedures per operator were included. Cumulative summation method was used to assess learning curves for diagnostic accuracy, false negative rate, pneumothorax rate, and hemoptysis rate. Operators were assessed individually and in a pooled analysis. Pneumothorax risk was also assessed in a model adjusting for risk factors. Acceptable failure rates were defined as 0.1 for diagnostic accuracy and false negative rate; 0.45 for pneumothorax rate; and 0.05 for hemoptysis rate. Results: The study included 3261 procedures in 3134 patients (mean age, 67.7±12.1 years; 1876 men, 1258 women). Overall diagnostic accuracy was 94.2% (2960/3141). All 17 operators achieved acceptable diagnostic accuracy [37 procedures required in pooled analysis; median of 33 procedures (range 19-67) required]. Overall false negative rate was 7.6% (179/2370). All 17 operators achieved acceptable false negative rate [52 procedures required in pooled analysis; median of 33 procedures (range 19-95) required]. Pneumothorax occurred in 32.6% (1063/3261), and hemoptysis in 2.7% (89/3261). All 17 operators achieved acceptable pneumothorax rate [20 procedures required in pooled analysis; median of 19 procedures (range 7-63) required]. In the risk-adjusted model, 15 operators achieved acceptable pneumothorax rate [54 procedures required in pooled analysis; median of 36 procedures (range 10-192) required]. Sixteen operators achieved acceptable hemoptysis rate [67 procedures required in pooled analysis; median of 55 procedures (range 41-152) required]. Conclusion: For CT-guided PTNB, at least 37 and 52 procedures are required to achieve acceptable diagnostic accuracy and false negative rate, respectively. Not all operators achieved acceptable complication rates. Clinical Impact: The findings may help set standards for training, supervision, and ongoing assessment of proficiency for this procedure.

Intravascular Ultrasound-Guided Transvenous Biopsy of Abdominal and Pelvic Targets Difficult to Access by Percutaneous Needle Biopsy: Technique and Initial Clinical Experience

PURPOSE

To report initial clinical experience with intravascular ultrasound (US)-guided transvenous biopsy (TVB) for perivascular target lesions in the abdomen and pelvis using side-viewing phased-array intracardiac echocardiography catheters.

MATERIALS AND METHODS

In this single-institution, retrospective study, 48 patients underwent 50 intravascular US-guided TVB procedures for targets close to the inferior vena cava or iliac veins deemed difficult to access by conventional percutaneous needle biopsy (PNB). In all procedures, side-viewing phased-array intracardiac echocardiography intravascular US catheters and transjugular liver biopsy sets were inserted through separate jugular or femoral vein access sheaths, and 18-gauge core needle biopsy specimens were obtained under real-time intravascular US guidance. Diagnostic yield, diagnostic accuracy, and complications were analyzed.

RESULTS

Intravascular US-guided TVB was diagnostic of malignancy in 40 of 50 procedures for a diagnostic yield of 80%. There were 5 procedures in which biopsy was correctly negative for malignancy, with a per-procedure diagnostic accuracy of 90% (45/50). Among the 5 false negatives, 2 patients underwent repeat intravascular US-guided TVB, which was diagnostic of malignancy for a per-patient diagnostic accuracy of 94% (45/48). There were 1 (2%) mild, 2 (4%) moderate, and 1 (2%) severe adverse events, with 1 moderate severity adverse event (venous thrombosis) directly attributable to the intravascular US-guided TVB technique.

CONCLUSIONS

Intravascular US-guided TVB performed on difficult-to-approach perivascular targets in the abdomen and pelvis resulted in a high diagnostic accuracy, similar to accepted thresholds for PNB. Complication rates may be slightly higher but should be weighed relative to the risks of difficult PNB, surgical biopsy, or clinical management without biopsy.