Contrast-enhanced endoscopic ultrasound for the differential diagnosis between benign and malignant lymph nodes: a meta-analysis

Diagnostic value of conventional endoscopic ultrasound for lymph node metastasis in upper gastrointestinal neoplasia: A meta-analysis

BACKGROUND

Upper gastrointestinal neoplasia mainly includes esophageal cancer and gastric cancer, both of which have high morbidity and mortality. Lymph node metastasis (LNM), as the most common metastasis mode of both diseases, is an important factor affecting tumor stage, treatment strategy and clinical prognosis. As a new fusion technology, endoscopic ultrasound (EUS) is becoming increasingly used in the diagnosis and treatment of digestive system diseases, but its use in detecting LNM in clinical practice remains limited.

AIM

To evaluate the diagnostic value of conventional EUS for LNM in upper gastrointestinal neoplasia.

METHODS

Using the search mode of "MeSH + Entry Terms" and according to the predetermined inclusion and exclusion criteria, we conducted a comprehensive search and screening of the PubMed, EMBASE and Cochrane Library databases from January 1, 2000 to October 1, 2022. Study data were extracted according to the predetermined data extraction form. The quality of the included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool, and the results of the quality assessment were presented using Review Manager 5.3.5 software. Finally, Stata14.0 software was used for a series of statistical analyses.

RESULTS

A total of 22 studies were included in our study, including 2986 patients. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic score and diagnostic odds ratio of conventional EUS in the diagnosis of upper gastrointestinal neoplasia LNM were 0.62 [95% confidence interval (CI): 0.50-0.73], 0.80 (95%CI: 0.73-0.86), 3.15 (95%CI: 2.46-4.03), 0.47 (95%CI: 0.36-0.61), 1.90 (95%CI: 1.51-2.29) and 6.67 (95%CI: 4.52-9.84), respectively. The area under the summary receiver operating characteristic curve was 0.80 (95%CI: 0.76-0.83). Sensitivity analysis indicated that the results of the meta-analysis were stable. There was considerable heterogeneity among the included studies, and the threshold effect was an important source of heterogeneity. Univariable meta-regression and subgroup analysis showed that tumor type, sample size and EUS diagnostic criteria were significant sources of heterogeneity in specificity (P < 0.05). No significant publication bias was found.

CONCLUSION

Conventional EUS has certain clinical value and can assist in the detection of LNM in upper gastrointestinal neoplasia, but it cannot be used as a confirmatory or exclusionary test.

Contrast-enhanced endoscopic ultrasound for swollen lymph nodes

Endoscopic ultrasound (EUS) is an important tool for the evaluation of lymphadenopathy, especially in intra-thoracic or intra-abdominal regions. EUS also provides tissue diagnosis via EUS fine-needle aspiration or biopsy. To select the target for biopsy or aspiration, conventional B-mode images are used for the evaluation, but this approach still lacks diagnostic accuracy. Contrast-enhanced EUS has been used to evaluate the vascularity of lesions. Most malignant lymphadenopathy shows heterogenous enhancement or defect of enhancement, while quantitative studies using time-intensity curves in contrast-enhanced harmonic EUS show a rapid decline in enhancement pattern. These findings are useful as an auxiliary method for tissue diagnosis or in cases in which tissue diagnosis is contraindicated.

Endoscopic Ultrasound Advanced Techniques for Diagnosis of Gastrointestinal Stromal Tumours

Gastrointestinal Stromal Tumors (GISTs) are subepithelial lesions (SELs) that commonly develop in the gastrointestinal tract. GISTs, unlike other SELs, can exhibit malignant behavior, so differential diagnosis is critical to the decision-making process. Endoscopic ultrasound (EUS) is considered the most accurate imaging method for diagnosing and differentiating SELs in the gastrointestinal tract by assessing the lesions precisely and evaluating their malignant risk. Due to their overlapping imaging characteristics, endosonographers may have difficulty distinguishing GISTs from other SELs using conventional EUS alone, and the collection of tissue samples from these lesions may be technically challenging. Even though it appears to be less effective in the case of smaller lesions, histology is now the gold standard for achieving a final diagnosis and avoiding unnecessary and invasive treatment for benign SELs. The use of enhanced EUS modalities and elastography has improved the diagnostic ability of EUS. Furthermore, recent advancements in artificial intelligence systems that use EUS images have allowed them to distinguish GISTs from other SELs, thereby improving their diagnostic accuracy.

Endoscopic ultrasonography: Enhancing diagnostic accuracy

Endoscopic ultrasound (EUS) is an essential technique for the management of several diseases. Over the years, new technologies have been developed because to improve and overcome certain limitations related to EUS guided tissue acquisition. Among these new methods, EUS guided elastography and contrast enhanced EUS has arisen as the most widely recognized and available. We will review in this manuscript the different techniques of elastography and contrast enhancement. Nowadays, there are well establish indications for advance imaging, mainly for supporting the management of pancreatic diseases (diagnosis of chronic pancreatitis and differential diagnosis of solid and cystic pancreatic tumors) and characterization of lymph nodes. However, there are more data on new potential indications for the near future.

Clinical features and 18F-FDG PET/CT for distinguishing of malignant lymphoma from inflammatory lymphadenopathy in HIV-infected patients

Background

It is vital to distinguish between inflammatory and malignant lymphadenopathy in human immunodeficiency virus (HIV) infected individuals. The purpose of our study was to differentiate the variations in the clinical characteristics of HIV patients, and apply ¹⁸F-FDG PET/CT parameters for distinguishing of malignant lymphoma and inflammatory lymphadenopathy in such patients.

Methods

This retrospective cross-sectional study included 59 consecutive HIV-infected patients who underwent whole-body ¹⁸F-FDG PET/CT. Of these patients, 37 had biopsy-proven HIV-associated lymphoma, and 22 with HIV-associated inflammatory lymphadenopathy were used as controls. The determined parameters were the maximum of standard uptake value (SUV_max), SUV_max of only lymph nodes (SUV_LN), the most FDG-avid lesion-to-liver SUV_max ratio (SUR_max), laboratory examinations and demographics. The optimal cut-off of ¹⁸F-FDG PET/CT value was analyzed by receiver operating characteristic curve (ROC).

Results

Considering the clinical records, the Karnofsky Performance Status (KPS) scores in patients with inflammatory lymphadenopathy were obviously higher than those in patients with malignant lymphoma (P = 0.015), whereas lymphocyte counts and lactate dehydrogenase (LDH) were obviously lower (P = 0.014 and 0.010, respectively). For the ¹⁸F-FDG PET/CT imaging, extra-lymphatic lesions, especially digestive tract and Waldeyer’s ring, occurred more frequently in malignant lymphoma than inflammatory lymphadenopathy. Furthermore, the SUR_max and SUV_LN in malignant lymphoma were markedly higher than those in inflammatory lymphadenopathy (P = 0.000 and 0.000, respectively). The cut-off point of 3.1 for SUR_max had higher specificity (91.9%) and relatively reasonable sensitivity (68.2%) and the cut-off point of 8.0 for the SUV_LN had high specificity (89.2%) and relatively reasonable sensitivity (63.6%).

Conclusion

Our study identified the distinctive characteristics of the clinical manifestations, the SUR_max, SUV_LN and detectability of extra-lymphatic lesions on ¹⁸F-FDG PET, and thus provides a new basis for distinguishing of malignant lymphoma from inflammatory lymphadenopathy in HIV-infected patients.

Endoscopic ultrasound fine-needle biopsy vs fine-needle aspiration for lymph nodes tissue acquisition: a systematic review and meta-analysis

Background

Endoscopic ultrasound (EUS)-guided tissue acquisition represents the choice of methods for suspected lymph nodes (LNs) located next to the gastrointestinal tract. This study aimed to compare the pooled diagnostic performance of EUS-guided fine-needle biopsy (EUS-FNB) and fine-needle aspiration (EUS-FNA) for LNs sampling.

Methods

We searched PubMed/MedLine and Embase databases through August 2021. Primary outcome was diagnostic accuracy; secondary outcomes were sensitivity, specificity, sample adequacy, optimal histological core procurement, number of passes, and adverse events. We performed a pairwise meta-analysis using a random-effects model. The results are presented as odds ratio (OR) or mean difference along with 95% confidence interval (CI).

Results

We identified nine studies (1,276 patients) in this meta-analysis. Among these patients, 66.4% were male; the median age was 67 years. Diagnostic accuracy was not significantly different between the two approaches (OR, 1.31; 95% CI, 0.81–2.10; P = 0.270). The accuracy of EUS-FNB was significantly higher when being performed with newer end-cutting needles (OR, 1.87; 95% CI, 1.17–3.00; P = 0.009) and in abdominal LNs (OR, 2.48; 95% CI, 1.52–4.05; P &lt; 0.001) than that of EUS-FNA. No difference in terms of sample adequacy was observed between the two approaches (OR, 1.40; 95% CI, 0.46–4.26; P = 0.550); however, histological core procurement and diagnostic sensitivity with EUS-FNB were significantly higher than those with EUS-FNA (OR, 6.15; 95% CI, 1.51–25.07; P = 0.010 and OR, 1.87; 95% CI, 1.27–2.74, P = 0.001). The number of needle passes needed was significantly lower in the EUS-FNB group than in the EUS-FNA group (mean difference, −0.54; 95% CI, −0.97 to −0.12; P = 0.010).

Conclusions

EUS-FNA and EUS-FNB perform similarly in LN sampling; however, FNB performed with end-cutting needles outperformed FNA in terms of diagnostic accuracy.

Endoscopic ultrasound assessment and tissue acquisition of mediastinal and abdominal lymph nodes

The differential diagnosis between benign and malignant lymph nodes (LNs) has a fundamental role in the characterization and staging of malignant conditions, as well as in subsequent patients’ management. All imaging modalities (i.e. computed tomography and magnetic resonance imaging) rely mainly on size; endoscopic ultrasound (EUS) criteria based on B-mode evaluation and Doppler features fail to adequately characterize with high specificity LNs nature. The introduction of EUS-elastography and contrast-enhanced harmonic EUS are useful techniques to increase the diagnostic yield in identifying metastatic LNs, to identify which suspicious LN should require pathological characterization and, finally, to target tissue acquisition. EUS-guided tissue acquisition (EUS-TA) is increasingly being used for diagnosing lymphadenopathy whenever the characterization modifies patients’ subsequent management and when no superficial LN is accessible. Since target therapy are currently available (i.e. lung cancer, breast cancer), EUS-TA of malignant LNs could be required to identify tumor biology. In this field, both fine needle aspiration and biopsy needles are able to guarantee accurate results with almost perfect specificity and sub-optimal sensitivity. We finally propose a diagnostic algorithm based on most recent, high-level evidence for the diagnostic approach to suspected LNs assessment.

Conservative management of malignant gastric outlet obstruction syndrome-evidence based evaluation of endoscopic ultrasound-guided gastroentero-anastomosis

Gastric outlet obstruction (GOO) is a clinical syndrome characterized by postprandial vomiting, abdominal pain, bloating and, in advanced cases, by weight loss secondary to inadequate oral intake. This clinical entity may be caused by mechanical obstruction, either benign or malignant, or by motility disorders. In this review we will focus on malignant GOO and on its endoscopic ultrasound (EUS)-guided palliative treatment. The most frequent malignant causes of this syndrome are gastric and locally advanced pancreatic carcinomas; other causes include duodenal or ampullary neoplasms, gastric lymphomas, retroperitoneal lymphadenopathies and, more infrequently, gallbladder and bile duct cancers. Surgery represents the treatment of choice when radical and curative resection is potentially feasible; if the malignant cause is not likely to be completely resected, palliative treatments should be proposed. Palliative treatments for malignant GOO are primarily based on surgical gastro-jejunostomy and endoscopic placement of an enteral self-expanding metal stent. Both treatments are effective; however, endoscopic stent placement is less invasive and it is associated with good short-term results, while surgery provides longer-lasting effects with a lower frequency of reintervention. In the last few years, EUS-guided gastroenterostomy (GE) has been proposed as palliative treatment for malignant GOO. This novel technique consists of the creation of an anastomosis between the gastric lumen and a small bowel loop distal to the malignant obstruction, through the deployment of a lumen-apposing metal stent under EUS-view. EUS-GE has the advantage of being as minimally invasive as enteral stent placement, and of guaranteeing long-term results similar to those of surgery.

High Diagnostic Accuracy and Safety of Endoscopic Ultrasound-Guided Fine-Needle Aspiration in Malignant Lymph Nodes: A Systematic Review and Meta-Analysis

BACKGROUND AND AIMS

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is increasingly being used for diagnosing lymphadenopathy. We aim to systematically review the accuracy of EUS-FNA in differentiating benign and malignant mediastinal and abdominal lymph nodes (LNs).

METHODS

A comprehensive literature search was performed on multiple electronic databases through February 2020. A random or fixed effect model generated the pooled sensitivity, specificity, likelihood ratio (LR), and diagnostic odds ratio (DOR) of EUS-FNA. Subgroup analyses and meta-regression were used to explore sources of heterogeneity.

RESULTS

Twenty-six studies involving 2753 patients with 2833 LNs were included. In the differential diagnosis of benign and malignant LNs, EUS-FNA had a pooled sensitivity, specificity, positive LR, and negative LR of 87% (95% confidence interval [CI] 86-90%), 100% (95% CI 99-100%), 68.98 (95% CI 42.10-113.02), and 0.14 (95% CI 0.11-0.17), respectively. The pooled rate of adverse events associated with EUS-FNA was 1.57% (95% CI 1.06-2.24%). The summary receiver operating characteristic (SROC) yielded an area under the curve (AUC) of 0.9912. EUS-FNA performed in mediastinal LNs gained a sensitivity of 85% (95% CI 81-88%), while in abdominal LNs, it reached 87% (95% CI 82-91%). The sensitivity of the subgroup with rapid on-site evaluation (ROSE) was 91% (95% CI 89-93%), while non-ROSE was 85% (95% CI 82-87%).

CONCLUSIONS

EUS-FNA is a sensitive, highly specific, and safe method for distinguishing benign and malignant mediastinal or abdominal LNs. However, the sensitivity of EUS-FNA still varies significantly among different centers.

Endoscopic ultrasound fine needle aspiration vs fine needle biopsy for pancreatic masses, subepithelial lesions, and lymph nodes

Endoscopic ultrasound tissue acquisition, in the form of both fine needle aspiration (EUS-FNA) and fine needle biopsy (EUS-FNB), is utilized for pancreatic mass lesions, subepithelial lesions, and lymph node biopsy. Both procedures are safe and yield high diagnostic value. Despite its high diagnostic yield, EUS-FNA has potential limitations associated with cytological aspirations, including inability to determine histologic architecture, and a small quantitative sample for further immunohistochemical staining. EUS-FNB, with its larger core biopsy needle, was designed to overcome these potential limitations. However, it remains unclear which technique should be used and for which lesions. Comparative trials are plagued by heterogeneity at every stage of comparison; including variable needles used, and different definitions of endpoints, which therefore limit generalizability. Thus, we present a review of prospective trials, systematic reviews, and meta-analyses on studies examining EUS-FNA vs EUS-FNB. Prospective comparative trials of EUS-FNA vs EUS-FNB primarily focus on pancreatic mass lesions, and yield conflicting results in terms of demonstrating the superiority of one method. However, consistent among trials is the potential for diagnosis with fewer passes, and a larger quantity of sample achieved for next generation sequencing. With regard to subepithelial lesions and lymph node biopsy, fewer prospective trials exist, and larger prospective studies are necessary. Based on the available literature, we would recommend EUS-FNB for peri-hepatic lymph nodes.

The Asian Federation of Societies for Ultrasound in Medicine and Biology (AFSUMB) Guidelines for Contrast-Enhanced Endoscopic Ultrasound

The Asian Federation of Societies for Ultrasound in Medicine and Biology aimed to provide information on techniques and indications for contrast-enhanced harmonic endoscopic ultrasound (CH-EUS), and to create statements including the level of recommendation. These statements are based on current scientific evidence reviewed by a Consensus Panel of 15 internationally renowned experts. The reliability of clinical questions was measured by agreement rates after voting. Six statements were made on techniques, including suitable contrast agents for CH-EUS, differences between contrast agents, setting of mechanical index, dual imaging and duration and phases for observation. Thirteen statements were made on indications, including pancreatic solid masses, pancreatic cancer staging, pancreatic cystic lesions and mural nodules, detection of subtle pancreatic lesions, gallbladder sludge and polyps, hepatic lesions, lymph nodes, subepithelial lesions, visceral vascular diseases, guidance of fine needle aspiration and evaluation for local therapy. These international expert consensus guidelines will assist endosonographers in conducting CH-EUS according to evidence-based information.

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.

New Devices for Endoscopic Treatments in Gastroenterology: A Narrative Review

Endoscopy is in a period of continuous innovations in terms of image quality, endoscopes, post-processing software and lastly, application of Artificial Intelligence. Therapeutic boundaries have expanded, widening the grey zone between endoscopy and surgery, and increasing endoscopic approaches in clinical scenarios where, until a few years ago, surgery was the only option. New scopes and accessories have made it easier to access critical areas such as the biliary tree and the small bowel intestine. In the field of hepato-pancreato-biliary endoscopy (HPB), it is now possible to directly access the biliary ducts or cystic lesions though dedicated stents and scopes, rather than having to rely only on fluoroscopy and ultrasound, increasing the diagnostic and therapeutic options by applying a three-dimensional approach. This narrative review will give an overview of some of the most relevant emerging fields in luminal and HPB endoscopy, highlighting advantages and main limitations of the techniques, and providing considerations for future development.

Do we need contrast agents for EUS?

We recently introduced a series of articles that dealt with controversies in EUS. In Part I, the authors discussed which clinical information is necessary prior to EUS and whether other imaging modalities are required before embarking on EUS examinations. Part II focuses on technical details and controversies about the use of EUS in special situations. In this article, important practical issues regarding the application of contrast-enhanced EUS in various clinical settings are raised and controversially discussed from different points of view.

Endoscopic ultrasound guided fine needle aspiration for the diagnosis of intra-abdominal lymphadenopathy: a systematic review and meta-analysis

Background: It is difficult to diagnose the cause of abdominal lymphadenopathy without determining the primary lesions. With the advent of curved ultrasound endoscopy, EUS-FNA can sample lymph nodes safely, accurately and conveniently. Due to the lack of formal quantitative and comprehensive literature review to determine the diagnostic value of EUS-FNA in the diagnosis of enlarged intra-abdominal lymph nodes of unknown origin, we conducted this study to systematically evaluate the diagnostic accuracy of EUS-FNA in the enlarged intra-abdominal lymph nodes.Methods: We performed a systematic review and meta-analysis to evaluate the accuracy of EUS-FNA for the diagnosis of intra-abdominal lymphadenopathy. We searched PubMed, Embase, and Cochrane Library to collect related studies and diagnostic performance data. We used a random-effects model to estimate the pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio (DOR). Heterogeneity was assessed by subgroup and meta-regression analysis.Results: Twelve eligible studies involved 774 patients were identified. The pooled sensitivity and specificity of all studies is 94% (95% CI: 91% to 96%) and 98% (95% CI: 96% to 99%), respectively. The pooled positive and negative likelihood ratios are 17.44 (95% CI, 6.50 to 46.79) and 0.09 (95% CI: 0.06 to 0.14). The pooled DOR is 277.82 (95% CI, 97.65 to 790.46).Conclusions: EUS-FNA is a safe and feasible technique with high sensitivity and specificity for the diagnosis of abdominal lymph node enlargement. Considering the limitations and heterogeneity, high-quality studies are needed to further explore the diagnostic value of EUS-FNA.

Endoscopic Ultrasound Fine-Needle Aspiration versus Fine-Needle Biopsy for Lymph Node Diagnosis: A Large Multicenter Comparative Analysis

Background/Aims

Endoscopic ultrasound fine-needle aspiration (EUS-FNA) is preferred for sampling of lymph nodes (LNs) adjacent to the gastrointestinal wall; however, fine-needle biopsy (FNB) may provide improved diagnostic outcomes. This study aimed to evaluate the comparative efficacy and safety of FNA versus FNB for LN sampling.

Methods

This was a multicenter retrospective study of prospectively collected data to evaluate outcomes of EUS-FNA and EUS-FNB for LN sampling. Characteristics analyzed included sensitivity, specificity, accuracy, the number of needle passes, diagnostic adequacy of rapid on-site evaluation (ROSE), cell-block analysis, and adverse events.

Results

A total of 209 patients underwent EUS-guided LN sampling. The mean lesion size was 16.22±8.03 mm, with similar sensitivity and accuracy between FNA and FNB ([67.21% vs. 75.00%, respectively, p=0.216] and [78.80% vs. 83.17%, respectively, p=0.423]). The specificity of FNB was better than that of FNA (100.00% vs. 93.62%, p=0.01). The number of passes required for diagnosis was not different. Abdominal and peri-hepatic LN location demonstrated FNB to have a higher sensitivity (81.08% vs. 64.71%, p=0.031 and 80.95% vs. 58.33%, p=0.023) and accuracy (88.14% vs. 75.29%, p=0.053 and 88.89% vs. 70.49%, p=0.038), respectively. ROSE was a significant predictor for accuracy (odds ratio, 5.16; 95% confidence interval, 1.15–23.08; p=0.032). No adverse events were reported in either cohort.

Conclusions

Both EUS-FNA and EUS-FNB are safe for the diagnosis of LNs. EUS-FNB is preferred for abdominal LN sampling. EUS-FNA+ ROSE was similar to EUS-FNB alone, showing better diagnosis for EUS-FNB than traditional FNA. While ROSE remained a significant predictor for accuracy, due to its poor availability in most centers, its use may be limited to cases with previous inconclusive diagnoses.