Contrast-enhanced harmonic endoscopic ultrasound-guided fine-needle aspiration in the diagnosis of solid pancreatic lesions: a retrospective study

Contrast-enhanced guided endoscopic ultrasound procedures

Contrast-enhanced endoscopic ultrasound (CH-EUS) can overcome the limitations of endoscopic ultrasound-guided acquisition by identifying microvessels inside inhomogeneous tumours and improving the characterization of these tumours. Despite the initial enthusiasm that oriented needle sampling under CH-EUS guidance could provide better diagnostic yield in pancreatic solid lesions, further studies did not confirm the supplementary values in cases of tissue acquisition guided by CH-EUS. This review details the knowledge based on the available data on contrast-guided procedures. The indications for CH-EUS tissue acquisition include isoechoic EUS lesions with poor visible delineation where CH-EUS can differentiate the lesion vascularisation from the surrounding parenchyma and also the mural nodules within biliopancreatic cystic lesions, which occur in select cases. Additionally, the roles of CH-EUS-guided therapy in patients whose pancreatic fluid collections or bile ducts that have an echogenic content have indications for drainage, and patients who have nonvisualized vessels that need to be highlighted via Doppler EUS are presented. Another indication is represented if there is a need for an immediate assessment of the post-radiofrequency ablation of pancreatic neuroendocrine tumours, in which case CH-EUS can be used to reveal the incomplete tumour destruction.

Basic Principles and Role of Endoscopic Ultrasound in Diagnosis and Differentiation of Pancreatic Cancer from Other Pancreatic Lesions: A Comprehensive Review of Endoscopic Ultrasound for Pancreatic Cancer

Pancreatic cancer is one of the leading causes of cancer-related deaths worldwide. Pancreatic lesions consist of both neoplastic and non-neoplastic lesions and often pose a diagnostic and therapeutic challenge due to similar clinical and radiological features. In recent years, pancreatic lesions have been discovered more frequently as incidental findings due to the increased utilization and widespread availability of abdominal cross-sectional imaging. Therefore, it becomes imperative to establish an early and appropriate diagnosis with meticulous differentiation in an attempt to balance unnecessary treatment of benign pancreatic lesions and missing the opportunity for early intervention in malignant lesions. Endoscopic ultrasound (EUS) has become an important diagnostic modality for the identification and risk stratification of pancreatic lesions due to its ability to provide detailed imaging and acquisition of tissue samples for analysis with the help of fine-needle aspiration/biopsy. The recent development of EUS-based technology, including contrast-enhanced endoscopic ultrasound, real-time elastography-endoscopic ultrasound, miniature probe ultrasound, confocal laser endomicroscopy, and the application of artificial intelligence has significantly augmented the diagnostic accuracy of EUS as it enables better evaluation of the number, location, dimension, wall thickness, and contents of these lesions. This article provides a comprehensive overview of the role of the different types of EUS available for the diagnosis and differentiation of pancreatic cancer from other pancreatic lesions while discussing their key strengths and important limitations.

Endoscopic Contrast-Enhanced Ultrasound and Fine-Needle Aspiration or Biopsy for the Diagnosis of Pancreatic Solid Lesions: A Systematic Review and Meta-Analysis

INTRODUCTION

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) and endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) are currently recommended for the pathologic diagnosis of pancreatic solid lesions (PSLs). The application of contrast-enhanced endoscopic ultrasound (ECEUS) could aid the endoscopist during an FNA and/or FNB procedure. CEUS is indeed able to better differentiate the pathologic tissue from the surrounding healthy pancreatic parenchyma and to detect necrotic areas and vessels.

OBJECTIVES

Our objective was to evaluate if ECEUS could reduce the number of needle passes and side effects and increase the diagnostic efficacy of FNA and/or FNB.

METHODS

A comprehensive literature search of clinical studies was performed to explore if ECEUS-FNA or FNB could increase diagnostic accuracy and reduce the number of needle passes and adverse effects compared to standard EUS-FNA or FNB. In accordance with the study protocol, a qualitative and quantitative analysis of the evidence was planned.

RESULTS

The proportion of established diagnoses of ECEUS was 90.9% compared to 88.3% of EUS, with no statistically significant difference (p = 0.14). The diagnosis was made through a single step in 70.9% of ECEUS patients and in 65.3% of EUS patients, without statistical significance (p = 0.24). The incidence of adverse reactions was substantially comparable across both groups (p = 0.89).

CONCLUSION

ECEUS-FNA and FNB do not appear superior to standard EUS-FNA and FNB for the diagnosis of pancreatic lesions.

Cutting edge of endoscopic ultrasound-guided fine-needle aspiration for solid pancreatic lesions

This article provides an extensive review of the advancements and future perspectives related to endoscopic ultrasound-guided tissue acquisition (EUS-TA) for the diagnosis of solid pancreatic lesions (SPLs). EUS-TA, including fine-needle aspiration (EUS-FNA) and fine-needle biopsy (EUS-FNB), has revolutionized the collection of specimens from intra-abdominal organs, including the pancreas. Improvements in the design of needles, collection methods, and specimen processing techniques have improved the diagnostic performance. This review highlights the latest findings regarding needle evolution, actuation number, sampling methods, specimen evaluation techniques, application of artificial intelligence (AI) for diagnostic purposes, and use of comprehensive genomic profiling (CGP). It acknowledges the rising use of Franseen and fork-tip needles for EUS-FNB and emphasizes that the optimal number of actuations requires further study. Methods such as the door-knocking and fanning techniques have shown promise for increasing diagnostic performance. Macroscopic on-site evaluation (MOSE) is presented as a practical rapid specimen evaluation method, and the integration of AI is identified as a potentially impactful development. The study also underscores the importance of optimal sampling for CGP, which can enhance the precision of cancer treatment. Ongoing research and technological innovations will further improve the accuracy and efficacy of EUS-TA.

Protocol for a Multi-Center Confirmatory Trial to Evaluate the Differential Diagnostic Performance of Contrast-Enhanced Ultrasonography Using Perflubutane in Patients with a Pancreatic Mass: A Multicenter Prospective Study

For pancreatic masses, an evaluation of their vascularity using contrast-enhanced ultrasonography can help improve their characterization. This study was designed to evaluate the utility and safety of contrast-enhanced transabdominal ultrasonography (CE-TUS) and endoscopic ultrasonography (CE-EUS) in the diagnosis of pancreatic masses including solid or cystic masses. This multi-center comparative open-label superiority study is designed to compare Plain (P)-TUS/EUS alone with P-TUS/P-EUS plus CE-TUS/CE-EUS. Three hundred and one patients with a total of 232 solid pancreatic masses and 69 cystic masses were prospectively enrolled. The primary endpoints are to compare the diagnostic accuracy between P-TUS/P-EUS alone and P-TUS/P-EUS plus CE-TUS/CE-EUS for both the TUS and EUS of solid pancreatic masses, and to compare the diagnostic accuracy between P-EUS alone and P-EUS plus CE-EUS in cystic pancreatic masses. The secondary endpoints are to compare the diagnostic sensitivity and specificity of P-TUS/P-EUS alone and P-TUS/P-EUS plus CE-TUS/CE-EUS for pancreatic solid/cystic masses, and the accuracy of P-TUS alone and P-TUS plus CE-TUS for pancreatic cystic masses. Other secondary endpoints included comparing the diagnostic sensitivity, specificity, and accuracy of CE-TUS, CE-EUS and CE-computed tomography (CT) for solid/cystic pancreatic masses. The safety, degree of effective enhancement, and diagnostic confidence obtained with CE-TUS/CE-EUS will also be assessed.

Artificial Intelligence in Endoscopic Ultrasonography-Guided Fine-Needle Aspiration/Biopsy (EUS-FNA/B) for Solid Pancreatic Lesions: Opportunities and Challenges

Solid pancreatic lesions (SPLs) encompass a variety of benign and malignant diseases and accurate diagnosis is crucial for guiding appropriate treatment decisions. Endoscopic ultrasonography-guided fine-needle aspiration/biopsy (EUS-FNA/B) serves as a front-line diagnostic tool for pancreatic mass lesions and is widely used in clinical practice. Artificial intelligence (AI) is a mathematical technique that automates the learning and recognition of data patterns. Its strong self-learning ability and unbiased nature have led to its gradual adoption in the medical field. In this paper, we describe the fundamentals of AI and provide a summary of reports on AI in EUS-FNA/B to help endoscopists understand and realize its potential in improving pathological diagnosis and guiding targeted EUS-FNA/B. However, AI models have limitations and shortages that need to be addressed before clinical use. Furthermore, as most AI studies are retrospective, large-scale prospective clinical trials are necessary to evaluate their clinical usefulness accurately. Although AI in EUS-FNA/B is still in its infancy, the constant input of clinical data and the advancements in computer technology are expected to make computer-aided diagnosis and treatment more feasible.

A review of contrast-enhanced harmonic endoscopic ultrasonography for pancreatic solid tumors

Endoscopic ultrasonography (EUS) is superior to other imaging modalities in the detection of pancreatic masses, although differentiating the types of pancreatic masses detected on EUS remains challenging. However, the value of contrast-enhanced harmonic EUS (CH-EUS) using ultrasound contrast agents for this differentiation has been reported. CH-EUS plays a pivotal role in analysis of small lesions that can only be detected with EUS. Recently, CH-EUS was used for staging and/or determining the resectability of pancreatic cancer in several clinical trials. In addition, it is used to estimate the response of pancreatic cancer to chemotherapy and to determine the prognosis in cases of pancreatic cancer and pancreatic neuroendocrine neoplasms. It is also postulated that CH-EUS improves the diagnostic performance of endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) through complementary diagnoses using CH-EUS and EUS-FNAB, or CH-EUS-guided EUS-FNAB. Thus, CH-EUS has been employed for various qualitative diagnoses, including differentiation of pancreatic masses. Second-generation contrast agents such as Sonazoid are used clinically for ultrasound diagnostic imaging of liver and breast disease. The positioning of CH-EUS with Sonazoid as a test for the diagnosis of solid pancreatic tumors is an issue for further studies.

Contrast-enhanced harmonic endoscopic ultrasound (CH-EUS) MASTER: A novel deep learning-based system in pancreatic mass diagnosis

BACKGROUND AND AIMS

Distinguishing pancreatic cancer from nonneoplastic masses is critical and remains a clinical challenge. The study aims to construct a deep learning-based artificial intelligence system to facilitate pancreatic mass diagnosis, and to guide EUS-guided fine-needle aspiration (EUS-FNA) in real time.

METHODS

This is a prospective study. The CH-EUS MASTER system is composed of Model 1 (real-time capture and segmentation) and Model 2 (benign and malignant identification). It was developed using deep convolutional neural networks and Random Forest algorithm. Patients with pancreatic masses undergoing CH-EUS examinations followed by EUS-FNA were recruited. All patients underwent CH-EUS and were diagnosed both by endoscopists and CH-EUS MASTER. After diagnosis, they were randomly assigned to undergo EUS-FNA with or without CH-EUS MASTER guidance.

RESULTS

Compared with manual labeling by experts, the average overlap rate of Model 1 was 0.708. In the independent CH-EUS video testing set, Model 2 generated an accuracy of 88.9% in identifying malignant tumors. In clinical trial, the accuracy, sensitivity, and specificity for diagnosing pancreatic masses by CH-EUS MASTER were significantly better than that of endoscopists. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were respectively 93.8%, 90.9%, 100%, 100%, and 83.3% by CH-EUS MASTER guided EUS-FNA, and were not significantly different compared to the control group. CH-EUS MASTER-guided EUS-FNA significantly improved the first-pass diagnostic yield.

CONCLUSION

CH-EUS MASTER is a promising artificial intelligence system diagnosing malignant and benign pancreatic masses and may guide FNA in real time.

TRIAL REGISTRATION NUMBER

NCT04607720.

Artificial intelligence in endoscopy: More than what meets the eye in screening colonoscopy and endosonographic evaluation of pancreatic lesions

Artificial intelligence (AI)-based tools have ushered in a new era of innovation in the field of gastrointestinal (GI) endoscopy. Despite vast improvements in endoscopic techniques and equipment, diagnostic endoscopy remains heavily operator-dependent, in particular, colonoscopy and endoscopic ultrasound (EUS). Recent reports have shown that as much as 25% of colonic adenomas may be missed at colonoscopy. This can result in an increased incidence of interval colon cancer. Similarly, EUS has been shown to have high inter-observer variability, overlap in diagnoses with a relatively low specificity for pancreatic lesions. Our understanding of Machine-learning (ML) techniques in AI have evolved over the last decade and its application in AI–based tools for endoscopic detection and diagnosis is being actively investigated at several centers. ML is an aspect of AI that is based on neural networks, and is widely used for image classification, object detection, and semantic segmentation which are key functional aspects of AI-related computer aided diagnostic systems. In this review, current status and limitations of ML, specifically for adenoma detection and endosonographic diagnosis of pancreatic lesions, will be summarized from existing literature. This will help to better understand its role as viewed through the prism of real world application in the field of GI endoscopy.

Is contrast-enhanced endoscopic ultrasound-guided fine needle biopsy better than conventional fine needle biopsy? A retrospective study in a medical center

Background

Contrast-enhanced endoscopic ultrasound-guided fine needle aspiration (CE-EUS-FNA) could help clinicians to precisely locate and puncture lesions, but its effect on the diagnostic yield improvement is controversial. We designed this study to observe the additional benefit of using contrast in EUS-guided tissue sampling while performing fine needle biopsy (FNB) instead of FNA, as FNB results in a higher diagnostic accuracy.

Method

Patients who underwent EUS-FNB performed by a single medical team from January 2019 to March 2021 were included in this study. We analyzed the cytopathological diagnostic accuracy rate and number of needle passes between groups who underwent FNB with and without contrast.

Result

We divided 133 patients who were diagnosed with a malignancy into two groups according to whether they underwent CE-EUS-FNB (n = 48) or conventional EUS-FNB (n = 85). The CE-EUS-FNB group had an equal diagnostic accuracy rate with fewer needle passes compared with the conventional EUS-FNB group. There was no significant trend change in the success cytopathological diagnostic rate for experienced endoscopists for EUS-FNA.

Conclusion

CE-EUS-FNB had fewer needle passes but no additional benefit for diagnostic yield improvement. There was no difficult threshold for CE-EUS-FNB for endoscopists who were well trained in conventional FNA.

The Utility of Endoscopic-Ultrasonography-Guided Tissue Acquisition for Solid Pancreatic Lesions

Endoscopic-ultrasonography-guided tissue acquisition (EUS-TA) has been widely performed for the definitive diagnosis of solid pancreatic lesions (SPLs). As the puncture needles, puncture techniques, and sample processing methods have improved, EUS-TA has shown higher diagnostic yields and safety. Recently, several therapeutic target genomic biomarkers have been clarified in pancreatic ductal carcinoma (PDAC). Although only a small proportion of patients with PDAC can benefit from precision medicine based on gene mutations at present, precision medicine will also be further developed for SPLs as more therapeutic target genomic biomarkers are identified. Advances in next-generation sequencing (NGS) techniques enable the examination of multiple genetic mutations in limited tissue samples. EUS-TA is also useful for NGS and will play a more important role in determining treatment strategies. In this review, we describe the utility of EUS-TA for SPLs.

Value of contrast-enhanced ultrasound combined with percutaneous ultrasound-guided fine-needle aspiration in the diagnosis of solid pancreatic lesions

Background:

Contrast-enhanced ultrasound (CEUS) can detect lesions hidden in inflammatory regions and find necrosis or areas of severe fibrosis within the lesion. This retrospective study aimed to compare the diagnostic accuracy of solid pancreatic lesions using percutaneous ultrasound (US)-guided fine-needle aspiration (FNA) with or without CEUS assessment.

Methods:

Clinical, imaging, and pathologic data of 181 patients from January 2014 to December 2018 in Pecking Union Medical College Hospital, with solid pancreatic masses who underwent percutaneous US-FNA and ThinPrep cytologic test were retrospectively evaluated. Patients were divided into CEUS and US groups according to whether CEUS was performed before the biopsy. According to FNA cytology diagnoses, we combined non-diagnostic, neoplastic, and negative cases into a negative category. The positive category included malignant, suspicious, and atypical cases. The final diagnosis was confirmed by pathology or clinical and radiological follow-up for at least 12 months. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of US-FNA were evaluated between the two groups.

Results:

This study enrolled 107 male and 74 female patients (average age: 60 years). There were 58 cases in the US group and 123 cases in the CEUS group. No statistically significant differences in age, gender, or lesion size were found between the two groups. The diagnostic accuracy of the CEUS group was 95.1% (117/123), which was higher than the 86.2% (50/58) observed in the US group (P = 0.036). The sensitivity, specificity, PPV, and NPV of the CEUS group were increased by 7.5%, 16.7%, 3.4%, and 18.8%, respectively, compared with the US group. However, the differences of the two groups were not statistically significant.

Conclusions:

Compared with the conventional US, the use of CEUS could improve the biopsy accuracy and avoid the need for a repeat biopsy, especially for some complicated FNA cases.

Contrast-enhanced harmonic endoscopic ultrasound-guided fine-needle aspiration versus standard fine-needle aspiration in pancreatic masses: a meta-analysis

OBJECTIVES

It is still unclear whether endoscopic ultrasound (EUS) contrast-enhanced fine-needle aspiration (CH-EUS-FNA) determines superior results in comparison to standard EUS-FNA in tissue acquisition of pancreatic masses. Aim of this meta-analysis was to compare the diagnostic outcomes of these two techniques.

METHODS

We searched the PubMed/Medline and Embase database through October 2020 and identified 6 studies, of which 2 randomized controlled trials (recruiting 701 patients). We performed pairwise meta-analysis through a random effects model and expressed data as odds ratio (OR) and 95% confidence interval (CI).

RESULTS

Pooled diagnostic sensitivity was 84.6% (95% CI 80.7%-88.6%) with CH-EUS-FNA and 75.3% (67%-83.5%) with EUS-FNA, with evidence of a significant superiority of the former (OR 1.74, 95% CI 1.26-2.40; p < 0.001). Subgroup analysis confirmed the superiority of CH-EUS-FNA over EUS-FNA only in larger lesions. Pooled diagnostic accuracy was 88.8% (85.6%-91.9%) in CH-EUS-FNA group and 83.6% (79.4%-87.8%) in EUS-FNA group (OR 1.52, 1.01-2.31; p = 0.05). Pooled sample adequacy was 95.1% (91.1%-99.1%) with CH-EUS-FNA and 89.4% (81%-97.8%) with EUS-FNA (OR 2.40, 1.38-4.17; p = 0.02).

CONCLUSION

CH-EUS-FNA seems to be superior to standard EUS-FNA in patients with pancreatic masses. Further trials are needed to confirm these results.

Contrast-enhanced harmonic versus standard endoscopic ultrasound-guided fine-needle aspiration in solid pancreatic lesions: a single-center prospective randomized trial

BACKGROUND

Contrast-enhanced harmonic endoscopic ultrasound (CH-EUS) can visualize necrotic areas and vessels inside lesions. CH-EUS findings combined with EUS-guided fine-needle aspiration (EUS-FNA) improves diagnosis in pancreatic solid masses. CH-EUS can also guide EUS-FNA (CH-EUS-FNA), potentially improving the diagnostic rate of EUS-FNA, but such superiority has not been proved in prospective studies. We aimed to assess whether CH-EUS-FNA is superior to standard EUS-FNA for specific diagnosis of solid pancreatic masses and what factors affect the diagnostic rate.

METHODS

This randomized controlled study in one tertiary medical academic center included patients with suspected pancreatic solid masses on transabdominal ultrasound or computed tomography (CT) scan. Two passes with a 22-G standard FNA needle were done using EUS-FNA and CH-EUS-FNA in random order, and the visible core obtained was sent for histological analysis. Final diagnosis was based on EUS-FNA or surgical specimen results and on 12-month follow-up by imaging.

RESULTS

148 patients were evaluated. EUS-FNA and CH-EUS-FNA showed diagnostic sensitivities of 85.5 % and 87.6 %, respectively (not significantly different) and the combined sensitivity of the two passes was 93.8 %. The false-negative rate was not significantly different when hypoenhanced or hyperenhanced lesions were compared with the EUS-FNA results. No differences were seen for the results related to location, size, tumor stage, chronic pancreatitis features, or presence of biliary plastic stent.

CONCLUSIONS

The diagnostic rates for samples obtained using 22-G needles with standard EUS-FNA and CH-EUS-FNA were not statistically significantly different.

The usefulness of EUS-FNA with contrast-enhanced harmonic imaging of solid pancreatic lesions: A prospective study

BACKGROUND AND AIM

Few studies have investigated endoscopic ultrasound-guided fine-needle aspiration with contrast-enhanced harmonic imaging (EUS-FNA-CHI) for diagnosing and adequately sampling pancreatic lesions. This study aimed to investigate the efficacy of EUS-FNA-CHI compared with that of endoscopic ultrasound-guided fine-needle aspiration with fundamental B mode imaging (EUS-FNA-FBI) for diagnosing solid pancreatic lesions.

METHODS

Consecutive patients with solid pancreatic lesions were enrolled prospectively (UMIN 000024467). Only samples obtained during the first needle pass (EUS-FNA-FBI) and second needle pass (EUS-FNA-CHI) were used to compare the accuracy rate for diagnosing pancreatic lesions and rate of adequate sampling for histological evaluation. In patients with hypo-enhancing lesions on contrast-enhanced harmonic EUS (CH-EUS), subgroup analyses were performed. Patients were classified into those with a heterogeneous area in the whole lesion (whole group), those with a heterogeneous area with a non-enhancing area (non-enhancing group), and those with a heterogeneous area with a homogeneous area (homogeneous group).

RESULTS

Ninety-three patients were enrolled. Overall, the rates of adequate sampling and sensitivity were significantly higher with EUS-FNA-CHI than with EUS-FNA-FBI (84.9% vs 68.8%, P = 0.003 and 76.5% vs 58.8%, P = 0.011, respectively). The adequate sampling rate and sensitivity were significantly higher with EUS-FNA-CHI than with EUS-FNA-FBI when the mass was > 15 mm. In the non-enhancing and homogeneous groups, the adequate sampling rate and sensitivity were significantly higher with EUS-FNA-CHI than with EUS-FNA-FBI.

CONCLUSIONS

CH-EUS enables improved observation of pancreatic lesions and helps identify the target of EUS-FNA among different pathological areas of the lesions particularly of > 15 mm.

Efficacy of EUS-guided FNB using a Franseen needle for tissue acquisition and microsatellite instability evaluation in unresectable pancreatic lesions

Background

The efficacy of immune checkpoint blockade in the treatment of microsatellite instability (MSI)-high tumors was recently reported. Therefore, the acquisition of histological specimens is desired in cases of unresectable solid pancreatic lesions (UR SPLs). This study investigated the efficacy of endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) using a Franseen needle for UR SPL tissue acquisition and MSI evaluation.

Methods

A total of 195 SPL patients who underwent EUS-guided fine-needle aspiration (EUS-FNA) or EUS-FNB (EUS-FNAB) between January 2017 and March 2020 were enrolled in this study. Among them, 89 SPL patients (FNB: 28, FNA: 61) underwent EUS-FNAB using a 22-G needle (UR SPLs: 58, FNB: 22, FNA: 36) (UR SPLs after starting MSI evaluation: 23, FNB: 9, FNA: 14).

Results

The puncture number was significantly lower with FNB than with FNA (median (range): 3 (2–5) vs 4 (1–8), P <  0.01, UR SPLs: 3 (2–5) vs 4 (1–8), P = 0.036). Histological specimen acquisition was more commonly achieved with FNB than with FNA (92.9% (26/28) vs 68.9% (42/61), P = 0.015, UR SPLs: 100% (22/22) vs 72.2% (26/36), P <  0.01). The histological specimen required for MSI evaluation was acquired more often with FNB than with FNA (88.9% (8/9) vs 35.7% (5/14), P = 0.03).

Conclusions

EUS-FNB using a Franseen needle is efficient for histological specimen acquisition and sampling the required amount of specimen for MSI evaluation in UR SPL patients.

Endoscopic Ultrasound-Guided Fine-Needle Aspiration (EUS-FNA) with Image Enhancement

Although endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is useful in the differential diagnosis of solid pancreatic lesions, lymph nodes, and liver lesions, inadequate sampling may result in an incorrect pathological diagnosis. The accuracy of EUS for the evaluation of pancreatobiliary lesions may be increased by image enhancement technologies, including contrast-enhanced harmonic (CH)-EUS and EUS-elastography. These methods can provide information that complement EUS-FNA for the diagnosis and staging of pancreatobiliary cancer, and can help to identify the EUS-FNA target, reducing the requirement for repeat FNA.

Contrast-Enhanced Harmonic Endoscopic Ultrasound-Guided Fine-Needle Aspiration versus Standard Fine-Needle Aspiration in Pancreatic Masses: A Propensity Score Analysis

Background: Whether endoscopic ultrasound (EUS) contrast-enhanced fine-needle aspiration (CH-EUS-FNA) determines superior results in comparison to standard EUS-FNA in tissue acquisition of pancreatic masses remains unclear. The aim of this study was to compare these two techniques on a series of patients with solid pancreatic lesions. Methods: 362 patients underwent EUS-FNA (2008–2019), after the propensity score matching of two groups were compared; 103 treated with CH-EUS-FNA (group 1) and 103 with standard EUS-FNA (group 2). The primary outcome was the diagnostic accuracy. Secondary outcomes were sensitivity, specificity, and sample adequacy. Results: Diagnostic sensitivity was 87.6% in group 1 and 80% in group 2 (p = 0.18). The negative predictive value was 56% in group 1 and 41.5% in group 2 (p = 0.06). The specificity and positive predictive values were 100% for both groups. Diagnostic accuracy was 89.3% and 82.5%, respectively (p = 0.40). Sample adequacy was 94.1% in group 1 and 91.2% in group 2 (p = 0.42). The rate of adequate core histologic samples was 33% and 28.1%, respectively (p = 0.44), and the number of needle passes to obtain adequate samples were 2.4 ± 0.6 and 2.7 ± 0.8, respectively (p = 0.76). These findings were confirmed in subgroup analyses, conducted according to lesion size and contrast enhancement pattern. Conclusions: CH-EUS-FNA does not appear to be superior to standard EUS-FNA in patients with pancreatic masses.

Endoscopic ultrasound-guided tissue sampling of pancreatic lesions

Important advancements in endoscopic ultrasound-guided tissue sampling techniques and development of new needle designs have improved the diagnostic yield of pancreatic lesions. This innovation in endoscopic ultrasound has also opened the door for early diagnosis and precision therapy in the management of cancer patients. Endoscopic ultrasound fine needle biopsy is an invaluable tool and newer biopsy designs will probably play a pivotal role in the management of pancreatic lesions in the next future. Aim of the current review was to provide an overview on the available techniques and devices for the endoscopic ultrasound-guided sampling of pancreatic solid and cystic lesions.

Endoscopic ultrasonography for pancreatic solid lesions

The incidence and mortality rates of pancreatic cancer, which has a poor prognosis, are rising rapidly. Endoscopic ultrasonography (EUS) provides superior spatial resolution compared with other imaging modalities such as transabdominal ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI), and it is considered among the most reliable and efficient diagnostic modalities for pancreatic diseases. In this review, we show that EUS is useful for detection of pancreatic solid lesions and staging of pancreatic cancer. EUS also plays an important role in screening patients with high-risk factors for pancreatic cancer. Although EUS is useful for detection of small pancreatic lesions, pancreatic lesions are difficult to characterize using this modality, because most pancreatic solid lesions appear hypoechoic on EUS. From this point of view, contrast-enhanced harmonic EUS (CH-EUS) plays an important role in the differential diagnosis of pancreatic lesions. EUS and CH-EUS are also useful for staging pancreatic cancer. Moreover, EUS-guided fine-needle aspiration (EUS-FNA) is superior to other modalities in terms of cytopathological diagnosis. Although EUS-FNA has a high diagnostic ability for pancreatic cancer, the combination of EUS-FNA and CH-EUS improves the diagnostic ability by decreasing the number of false-negative cases. Thus, conventional EUS, EUS-FNA, and CH-EUS are essential in clinical practice for the diagnosis of pancreatic solid lesions.

Endoscopic ultrasonography in pancreatic diseases: advances in tissue acquisition

Background and study aims  Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) improved the diagnostic performance and upgraded the role of endoscopic ultrasonography (EUS) into an interventional modality, able to guide patient management and treatment.This review aimed to highlight the advances, emerging practices, procedural techniques and technological innovations in EUS tissue acquisition in pancreatic diseases. Methods  A thorough review of the literature was performed using PubMed to identify articles that describe techniques, advances, and practices in EUS tissue acquisition in gastrointestinal diseases. Conclusion  Since the first EUS-FNA procedure, EUS guided-tissue acquisition has been evolving continuously. Development of needles with innovative tip design enabled procurement of larger samples with preserved histological architecture. Moreover, sampling techniques and complementary methods, such as contrast harmonic imaging and EUS-elastography, have been introduced in an effort to improve diagnostic performance and sample adequacy.

Early pancreatic cancer - The role of endoscopic ultrasound with or without tissue acquisition in diagnosis and staging

Pancreatic cancer (PC) is one of the deadliest cancers with a 5-year overall survival of less than 6%. Due to its insidious clinical course and unspecific symptoms, the diagnosis is usually late, with only 15-20% patients presenting with potentially curable disease. It is, therefore, extremely important to identify patients with PC at early stages of the disease when tumors may be amenable to surgical resection. For unresectable and borderline resectable PC it is consensual to perform a biopsy to have a cyto/histological confirmation of malignancy before treatment. However, for patients presenting with promptly resectable disease, the role of biopsy is more debatable. There are, in the literature, arguments both for and against the usefulness of a preoperative biopsy. Endoscopic ultrasound (EUS) is an important technique assisting in the diagnosis and staging of PC. EUS-guided tissue acquisition is a well-established tool to demonstrate the malignant nature of a pancreatic lesion. This review focuses on the role of EUS in the diagnosis and staging of PC, and highlights the controversy related to the role of EUS-guided tissue acquisition in the preoperative assessment of patients presenting with promptly resectable tumors (early PC).

Comparison between 22G aspiration and 22G biopsy needles for EUS-guided sampling of pancreatic lesions: A meta-analysis

Robust data in favor of clear superiority of 22G fine-needle biopsy (FNB) over 22G FNA for an echoendoscopic-guided sampling of pancreatic masses are lacking. The objective of this study is to compare the diagnostic outcomes and sample adequacy of these two needles. Computerized bibliographic search on the main databases was performed and restricted to only randomized controlled trials. Summary estimates were expressed regarding risk ratio (RR) and 95% confidence interval. A total of 11 trials with 833 patients were analyzed. The two needles resulted comparable in terms of diagnostic accuracy (RR 1.02, 0.97–1.08; P = 0.46), sample adequacy (RR 1.01, 0.96–1.06; P = 0.61), and histological core procurement (RR 1.01, 0.89–1.15; P = 0.86). Pooled sensitivity in the diagnosis of pancreatic cancer was 93.1% (87.9%–98.4%) and 90.4% (86.3%–94.5%) with biopsy and aspirate, respectively, whereas specificity for detecting pancreatic cancer was 100% with both needles. Analysis of the number of needle passes showed a nonsignificantly positive trend in favor of FNB (mean difference: −0.32, −0.66–0.02; P = 0.07). Our meta-analysis stands for a nonsuperiority of 22G FNB over 22G FNA; hence, no definitive recommendations on the use of a particular device can be made.

Contrast-enhanced ultrasonography in interventional oncology

Contrast-enhanced ultrasound (CEUS) has evolved from the use of agitated saline to second generation bioengineered microbubbles designed to withstand insonation with limited destruction. While only one of these newer agents is approved by the Food and Drug Administration for use outside echocardiography, interventional radiologists are increasingly finding off-label uses for ultrasound contrast agents. Notably, these agents have an extremely benign safety profile with no hepatic or renal toxicities and no radiation exposure. Alongside diagnostic applications, CEUS has begun to develop its own niche within the realm of interventional oncology. Certainly, the characterization of focal solid organ lesions (such as hepatic and renal lesions) by CEUS has been an important development. However, interventional oncologists are finding that the dynamic and real-time information afforded by CEUS can improve biopsy guidance, ablation therapy, and provide early evidence of tumor viability after locoregional therapy. Even more novel uses of CEUS include lymph node mapping and sentinel lymph node localization. Critical areas of research still exist. The purpose of this article is to provide a narrative review of the emerging roles of CEUS in interventional oncology.

A quarter century of EUS-FNA: Progress, milestones, and future directions

Tissue acquisition using EUS has considerably evolved since the first EUS-FNA was reported 25 years ago. Its introduction was an important breakthrough in the endoscopic field. EUS-FNA has now become a part of the diagnostic and staging algorithm for the evaluation of benign and malignant diseases of the gastrointestinal tract and of the organs in its proximity, including lung diseases. This review aims to present the history of EUS-FNA development and to provide a perspective on the recent developments in procedural techniques and needle technologies that have significantly extended the role of EUS and its clinical applications. There is a bright future ahead for EUS-FNA in the years to come as extensive research is conducted in this field and various technologies are continuously implemented into clinical practice.

Association between pathologic grade and multiphase computed tomography enhancement in pancreatic neuroendocrine neoplasm

BACKGROUND AND AIM

Pancreatic neuroendocrine neoplasms (PanNENs) are rare diseases but gradually increasing in prevalence with different prognosis. Multiphase contrast-enhanced computed tomography (CT) is known as widely used imaging modality for the diagnosis of pancreatic tumors. We aimed to investigate whether CT enhancement pattern is associated with the pathologic tumor grade and can predict that of PanNEN.

METHODS

Ninety PanNEN patients who underwent multiphase enhanced CT before pathologic diagnosis were retrospectively reviewed. CT enhancement values at each phase were measured, and its relation with pathologic grade was assessed.

RESULTS

Ninety PanNENs included 62 G1 (68.9%), 21 G2 (23.3%), and 7 G3 (7.8%). The enhancement values of the early arterial phase were significantly different among three groups (G1 119.4 HU, G2 94.7 HU, and G3 64.8 HU; G1 vs G2, P = 0.043; G1 vs G3, P = 0.001; and G2 vs G3, P = 0.027). In the late arterial phase, there was a difference between grade 1/2 and 3 but no significant difference between grade 1 and grade 2 (G1 164.3 HU, G2 142.9 HU, and G3 94.1 HU; G1 vs G2, P = 0.804; G1 vs G3, P = 0.016; and G2 vs G3, P = 0.022). The enhancement value of the portal phase did not differ significantly among the three groups. Diagnostic ability of the early arterial enhancement value for the differentiation of the G1 (cutoff 109.5 HU, sensitivity 73.3%, and specificity 62.5%) was comparable with that of the tumor size (cutoff 20.5 mm, sensitivity 68.9%, and specificity 66.7%).

CONCLUSIONS

Computed tomography enhancement value at early arterial phase and its changing pattern can be a useful predictor for the differentiation of pathologic grade of PanNENs.

New Imaging Techniques for Endoscopic Ultrasonography: Contrast-Enhanced Endoscopic Ultrasonography

Conventional endoscopic ultrasonography (EUS) has limitations in the diagnosis of solid masses. Because most are depicted as a hypoechoic mass, without cytology or biopsy, it can be difficult to distinguish inflammatory masses from malignancy. Recently developed, contrast-enhanced harmonic EUS (CH-EUS) has improved characterization of digestive lesions by depicting microvessels and parenchymal perfusion, particularly for differentiating pancreatic cancer from other pancreatic solid lesions, identifying mural nodules in intraductal papillary mucinous neoplasms, and estimating malignant potential of gastrointestinal stromal tumors. CH-EUS is complementary to EUS-guided fine-needle aspiration for diagnosing pancreatic lesions, staging, and predicting chemotherapy response.

Contrast-enhanced harmonic endoscopic ultrasonography in gallbladder cancer and pancreatic cancer

Endoscopic ultrasonography (EUS) plays a major role in diagnosing gallbladder (GB) cancer and pancreatic cancer (PC). In cases of GB cancer, EUS allows for precise observations of morphology and wall layers. However, proficiency is required for the morphologic diagnosis of GB tumors. Therefore, contrast-enhanced harmonic EUS (CH-EUS) began to be performed to diagnose GB lesions. CH-EUS enables real-time observation of the hemodynamics of GB tumors. The enhanced patterns generated by CH-EUS improve precision in the diagnosis of such tumors.PC appears as a hypoechoic mass on EUS. However, distinguishing between PC and mass-forming pancreatitis or focal autoimmune pancreatitis (AIP) is difficult via conventional EUS. CH-EUS allows for differentiating among these diseases (PC is hypoenhanced and heterogeneously enhanced, pancreatitis is isoenhanced, and a pancreatic neuroendocrine tumor is hyperenhanced). EUS-guided fine needle aspiration (EUS-FNA) also contributes to pathological diagnoses of pancreatic lesions. However, certain PC patients cannot be diagnosed via EUS-FNA. PC is heterogeneously enhanced on CH-EUS, and unenhanced regions have been reported to be areas of fibrosis or necrosis. CH-EUS-guided fine needle aspiration (CH-EUS-FNA) permits puncturing of the enhanced area while avoiding necrotic and fibrotic regions. Moreover, as CH-EUS findings have been quantitatively analyzed, a time-intensity curve (TIC) has become usable for diagnosing solid pancreatic lesions. CH-EUS-related techniques have been developed and increasingly utilized in the pancreaticobiliary area.

Imaging modalities for characterising focal pancreatic lesions

BACKGROUND

Increasing numbers of incidental pancreatic lesions are being detected each year. Accurate characterisation of pancreatic lesions into benign, precancerous, and cancer masses is crucial in deciding whether to use treatment or surveillance. Distinguishing benign lesions from precancerous and cancerous lesions can prevent patients from undergoing unnecessary major surgery. Despite the importance of accurately classifying pancreatic lesions, there is no clear algorithm for management of focal pancreatic lesions.

OBJECTIVES

To determine and compare the diagnostic accuracy of various imaging modalities in detecting cancerous and precancerous lesions in people with focal pancreatic lesions.

SEARCH METHODS

We searched the CENTRAL, MEDLINE, Embase, and Science Citation Index until 19 July 2016. We searched the references of included studies to identify further studies. We did not restrict studies based on language or publication status, or whether data were collected prospectively or retrospectively.

SELECTION CRITERIA

We planned to include studies reporting cross-sectional information on the index test (CT (computed tomography), MRI (magnetic resonance imaging), PET (positron emission tomography), EUS (endoscopic ultrasound), EUS elastography, and EUS-guided biopsy or FNA (fine-needle aspiration)) and reference standard (confirmation of the nature of the lesion was obtained by histopathological examination of the entire lesion by surgical excision, or histopathological examination for confirmation of precancer or cancer by biopsy and clinical follow-up of at least six months in people with negative index tests) in people with pancreatic lesions irrespective of language or publication status or whether the data were collected prospectively or retrospectively.

DATA COLLECTION AND ANALYSIS

Two review authors independently searched the references to identify relevant studies and extracted the data. We planned to use the bivariate analysis to calculate the summary sensitivity and specificity with their 95% confidence intervals and the hierarchical summary receiver operating characteristic (HSROC) to compare the tests and assess heterogeneity, but used simpler models (such as univariate random-effects model and univariate fixed-effect model) for combining studies when appropriate because of the sparse data. We were unable to compare the diagnostic performance of the tests using formal statistical methods because of sparse data.

MAIN RESULTS

We included 54 studies involving a total of 3,196 participants evaluating the diagnostic accuracy of various index tests. In these 54 studies, eight different target conditions were identified with different final diagnoses constituting benign, precancerous, and cancerous lesions. None of the studies was of high methodological quality. None of the comparisons in which single studies were included was of sufficiently high methodological quality to warrant highlighting of the results. For differentiation of cancerous lesions from benign or precancerous lesions, we identified only one study per index test. The second analysis, of studies differentiating cancerous versus benign lesions, provided three tests in which meta-analysis could be performed. The sensitivities and specificities for diagnosing cancer were: EUS-FNA: sensitivity 0.79 (95% confidence interval (CI) 0.07 to 1.00), specificity 1.00 (95% CI 0.91 to 1.00); EUS: sensitivity 0.95 (95% CI 0.84 to 0.99), specificity 0.53 (95% CI 0.31 to 0.74); PET: sensitivity 0.92 (95% CI 0.80 to 0.97), specificity 0.65 (95% CI 0.39 to 0.84). The third analysis, of studies differentiating precancerous or cancerous lesions from benign lesions, only provided one test (EUS-FNA) in which meta-analysis was performed. EUS-FNA had moderate sensitivity for diagnosing precancerous or cancerous lesions (sensitivity 0.73 (95% CI 0.01 to 1.00) and high specificity 0.94 (95% CI 0.15 to 1.00), the extremely wide confidence intervals reflecting the heterogeneity between the studies). The fourth analysis, of studies differentiating cancerous (invasive carcinoma) from precancerous (dysplasia) provided three tests in which meta-analysis was performed. The sensitivities and specificities for diagnosing invasive carcinoma were: CT: sensitivity 0.72 (95% CI 0.50 to 0.87), specificity 0.92 (95% CI 0.81 to 0.97); EUS: sensitivity 0.78 (95% CI 0.44 to 0.94), specificity 0.91 (95% CI 0.61 to 0.98); EUS-FNA: sensitivity 0.66 (95% CI 0.03 to 0.99), specificity 0.92 (95% CI 0.73 to 0.98). The fifth analysis, of studies differentiating cancerous (high-grade dysplasia or invasive carcinoma) versus precancerous (low- or intermediate-grade dysplasia) provided six tests in which meta-analysis was performed. The sensitivities and specificities for diagnosing cancer (high-grade dysplasia or invasive carcinoma) were: CT: sensitivity 0.87 (95% CI 0.00 to 1.00), specificity 0.96 (95% CI 0.00 to 1.00); EUS: sensitivity 0.86 (95% CI 0.74 to 0.92), specificity 0.91 (95% CI 0.83 to 0.96); EUS-FNA: sensitivity 0.47 (95% CI 0.24 to 0.70), specificity 0.91 (95% CI 0.32 to 1.00); EUS-FNA carcinoembryonic antigen 200 ng/mL: sensitivity 0.58 (95% CI 0.28 to 0.83), specificity 0.51 (95% CI 0.19 to 0.81); MRI: sensitivity 0.69 (95% CI 0.44 to 0.86), specificity 0.93 (95% CI 0.43 to 1.00); PET: sensitivity 0.90 (95% CI 0.79 to 0.96), specificity 0.94 (95% CI 0.81 to 0.99). The sixth analysis, of studies differentiating cancerous (invasive carcinoma) from precancerous (low-grade dysplasia) provided no tests in which meta-analysis was performed. The seventh analysis, of studies differentiating precancerous or cancerous (intermediate- or high-grade dysplasia or invasive carcinoma) from precancerous (low-grade dysplasia) provided two tests in which meta-analysis was performed. The sensitivity and specificity for diagnosing cancer were: CT: sensitivity 0.83 (95% CI 0.68 to 0.92), specificity 0.83 (95% CI 0.64 to 0.93) and MRI: sensitivity 0.80 (95% CI 0.58 to 0.92), specificity 0.81 (95% CI 0.53 to 0.95), respectively. The eighth analysis, of studies differentiating precancerous or cancerous (intermediate- or high-grade dysplasia or invasive carcinoma) from precancerous (low-grade dysplasia) or benign lesions provided no test in which meta-analysis was performed.There were no major alterations in the subgroup analysis of cystic pancreatic focal lesions (42 studies; 2086 participants). None of the included studies evaluated EUS elastography or sequential testing.

AUTHORS' CONCLUSIONS

We were unable to arrive at any firm conclusions because of the differences in the way that study authors classified focal pancreatic lesions into cancerous, precancerous, and benign lesions; the inclusion of few studies with wide confidence intervals for each comparison; poor methodological quality in the studies; and heterogeneity in the estimates within comparisons.

Maximizing the endosonography: The role of contrast harmonics, elastography and confocal endomicroscopy

New technologies in endoscopic ultrasound (EUS) evaluation have been developed because of the need to improve the EUS and EUS-fine needle aspiration (EUS-FNA) diagnostic rate. This paper reviews the principle, indications, main literature results, limitations and future expectations for each of the methods presented. Contrast-enhanced harmonic EUS uses a low mechanical index and highlights slow-flow vascularization. This technique is useful for differentiating solid and cystic pancreatic lesions and assessing biliary neoplasms, submucosal neoplasms and lymph nodes. It is also useful for the discrimination of pancreatic masses based on their qualitative patterns; however, the quantitative assessment needs to be improved. The detection of small solid lesions is better, and the EUS-FNA guidance needs further research. The differentiation of cystic lesions of the pancreas and the identification of the associated malignancy features represent the main indications. Elastography is used to assess tissue hardness based on the measurement of elasticity. Despite its low negative predictive value, elastography might rule out the diagnosis of malignancy for pancreatic masses. Needle confocal laser endomicroscopy offers useful information about cystic lesions of the pancreas and is still under evaluation for use with solid pancreatic lesions of lymph nodes.

Harmonic contrast-enhanced endoscopic ultrasound fine-needle aspiration: Fact or fiction?

The negative predictive value of endoscopic ultrasonography fine-needle aspiration is relatively low. To achieve the improvement of the diagnostic yield, the following were proposed: a higher number of passes, the presence of the rapid on-site cytopathologist evaluation, the fanning technique, or the repetition of the fine needle biopsy. Harmonic contrast-enhanced endosonography may better identify the targeted area in the lesions by avoiding the inside necrosis and the vessels of fibrosis, so it can guide the fine-needle aspiration. Both techniques are complementary, not competitive, and they can be done in the same session. The combined technique is simple, safe, and requires only a few minutes with minimal extra costs compared to standard fine-needle aspiration. It minimally increases the diagnostic rate, and it permits the decrease of the number of passes. However, we will know its real clinical impact only in the future and whether it will be incorporated into the lesion assessment process.

Early detection of pancreatic cancer: impact of high-resolution imaging methods and biomarkers

High-resolution imaging methods (HRIMs) and biomarkers present the second step of pancreatic cancer (PC) diagnostics in at-risk individuals. These include patients with positive risk factors, early symptoms, nonresponders to the initial antidiabetic therapy, patients older than 50 years of age with new-onset unstable diabetes requiring insulin as well as patients with long-term insulin-non-dependent diabetes and recent (up to 6 months) failure of antidiabetic therapy. The procedures should be started without delay and the co-operation between the primary and tertiary medical centers is highly desirable. An early indication of HRIMs and biomarkers is a prerequisite for the diagnosis of a resectable PC. This publication reviews the recent contribution of HRIMs and biomarkers toward an early diagnosis of PC.

The clinical impact of ultrasound contrast agents in EUS: a systematic review according to the levels of evidence

BACKGROUND AND AIMS

The use of contrast-harmonic EUS (CH-EUS) in routine clinical practice is increasing rapidly but is not yet standardized. We present the levels of evidence (LEs) found in the literature to put its clinical outcomes in the appropriate perspective.

METHODS

We conducted a systematic review of the available English-language articles. The LEs were stratified according to the Oxford Centre for Evidence-Based Medicine guidelines.

RESULTS

Overall, 210 articles were included and presented according to different pathologic conditions. For pancreatic solid neoplasms, the pooled sensitivity and specificity in the diagnosis of pancreatic carcinoma were very high (LE 1); quantitative analysis and guidance of FNA were reported as investigational research (LE 2-3). For pancreatic cystic lesions, the identification of neoplastic solid components as hyperenhanced lesions represented a promising application of CH-EUS (LE 2). For lymph nodes, CH-EUS increased the diagnostic yield of B-mode EUS for the detection of malignancy (LE 2). For submucosal tumors, CH-EUS seemed useful for differential diagnosis and risk stratification (LE 2-3). For other applications, differential diagnosis of gallbladder and vascular abnormalities by CH-EUS were reported (LE 2-3).

CONCLUSIONS

The LEs of CH-EUS in the literature have evolved from the initial descriptive studies to multicenter and prospective trials, and even meta-analyses. The differential diagnosis between benign and malignant lesions is the main field of application of CH-EUS. With regard to pancreatic solid neoplasms, the concomitant use of both CH-EUS and EUS-FNA may have additive value in increasing the overall accuracy by overcoming the false-negative results associated with each individual technique. Other applications are promising but still investigational.

Efforts to improve the diagnostic accuracy of endoscopic ultrasound-guided fine-needle aspiration for pancreatic tumors

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is widely used to obtain a definitive diagnosis of pancreatic tumors. Good results have been reported for its diagnostic accuracy, with high sensitivity and specificity of around 90%; however, technological developments and adaptations to improve it still further are currently underway. The endosonographic technique can be improved when several tips and tricks useful to overcome challenges of EUS-FNA are known. This review provides various techniques and equipment for improvement in the diagnostic accuracy in EUS-FNA.