Effectiveness of contrast-enhanced harmonic endoscopic ultrasound for the evaluation of solid pancreatic masses

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.

Efficacy of Contrast-Enhanced Harmonic Endoscopic Ultrasound for Pancreatic Solid Tumors with a Combination of Qualitative and Quantitative Analyses: A Prospective Pilot Study

INTRODUCTION

Image evaluation of contrast-enhanced harmonic endoscopic ultrasound (CEH-EUS) and additional time-intensity curve (TIC) analysis enable qualitative and quantitative analyses of pancreatic tumor based on real-time perfusion imaging.

AIMS

To evaluate the efficacy of CEH-EUS with a combination of qualitative and quantitative analyses of pancreatic solid tumors.

METHODS

Patients were scheduled to undergo EUS-guided fine needle aspiration (FNA) for pancreatic solid tumors were prospectively enrolled between 11/2016 and 12/2018 and underwent CEH-EUS. The vascular and enhancement patterns were qualitatively evaluated and heterogeneous enhancement was defined to be indicative of malignancy. The echo intensity change during 60 s in the tumor was quantitatively evaluated by time intensity curve analysis.

RESULTS

In total, 100 patients were enrolled in this study. The final diagnoses were malignant lesions in 87 patients and benign legions in 13 patients. There were four categories of enhancement and patterns: hypovascular with heterogeneous, hypovascular with homogeneous, hypervascular heterogeneous, and hypervascular homogeneous enhancement. The diagnostic capability of qualitative analysis was the sensitivity, specificity, and accuracy of 89%, 62%, and 85%, respectively. With respect to time intensity curve analysis, the time to peak of malignant lesions was significantly shorter than those of benign lesions (P = 0.0009) with an optimal cutoff value of 12.81 s on the receiver operating characteristic curve analysis. With the combination of qualitative and quantitative analyses, the sensitivity, specificity, and accuracy were improved to 100%, 54%, and 94%, respectively.

CONCLUSIONS

CEH-EUS with combined qualitative and quantitative analyses for pancreatic tumors might be useful as a complement for EUS-FNA. The UMIN Clinical Trials Registry (UMIN000025192).

Tissue harmonic versus contrast-enhanced harmonic endoscopic ultrasonography for the diagnosis of pancreatic tumors: Prospective multicenter study

OBJECTIVES

This prospective multicenter study aimed to assess and compare the accuracy of tissue harmonic endoscopic ultrasonography (TH-EUS) and contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) for differentiating pancreatic carcinoma from other pancreatic tumors.

METHODS

Consecutive patients with solid pancreatic tumors were prospectively enrolled between August 2013 and December 2014. To assess the accuracy of TH-EUS and CH-EUS, we compared four parameters of TH-EUS (fuzzy edge, irregular periphery, hypoechogenicity, and heterogeneous internal echogenicity) and four parameters of CH-EUS (hypoenhancement and heterogeneous enhancement in the early and late phases, respectively) to investigate which parameter of each method was most suitable to diagnose pancreatic carcinomas. Interobserver agreement and the diagnostic ability of pancreatic carcinoma using TH-EUS and CH-EUS were assessed and compared.

RESULTS

A total of 204 patients were enrolled. For the diagnosis of pancreatic carcinoma, interobserver agreement by experts and nonexperts was 0.33-0.50 and 0.35-0.50 for TH-EUS, respectively, and 0.72-0.74 and 0.20-0.54 for CH-EUS, respectively. Irregular periphery was the most accurate diagnostic parameter among TH-EUS findings for differentiating pancreatic carcinomas, with sensitivity, specificity, and accuracy of 95.0%, 42.9%, and 78.9%, respectively. Late phase hypoenhancement was the most accurate diagnostic parameter among CH-EUS findings for differentiating pancreatic carcinomas, with sensitivity, specificity, and accuracy of 90.8%, 74.6%, and 85.8%, respectively. The accuracy of CH-EUS (late phase hypoenhancement) for diagnosis of pancreatic carcinoma was significantly higher than that of TH-EUS (irregular periphery) (p < 0.001).

CONCLUSION

In comparison with TH-EUS, CH-EUS increased the diagnostic ability and reproducibility for the diagnosis of pancreatic carcinoma. UMIN (000011124).

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.

Role of Endoscopic Ultrasonography and Endoscopic Retrograde Cholangiopancreatography in the Diagnosis of Pancreatic Cancer

Pancreatic cancer has the poorest prognosis among all cancers, and early diagnosis is essential for improving the prognosis. Along with radiologic modalities, such as computed tomography (CT) and magnetic resonance imaging (MRI), endoscopic modalities play an important role in the diagnosis of pancreatic cancer. This review evaluates the roles of two of those modalities, endoscopic ultrasonography (EUS) and endoscopic retrograde cholangiopancreatography (ERCP), in the diagnosis of pancreatic cancer. EUS can detect pancreatic cancer with higher sensitivity and has excellent sensitivity for the diagnosis of small pancreatic cancer that cannot be detected by other imaging modalities. EUS may be useful for the surveillance of pancreatic cancer in high-risk individuals. Contrast-enhanced EUS and EUS elastography are also useful for differentiating solid pancreatic tumors. In addition, EUS-guided fine needle aspiration shows excellent sensitivity and specificity, even for small pancreatic cancer, and is an essential examination method for the definitive pathological diagnosis and treatment decision strategy. On the other hand, ERCP is invasive and performed less frequently for the purpose of diagnosing pancreatic cancer. However, ERCP is essential in cases that require evaluation of pancreatic duct stricture that may be early pancreatic cancer or those that require differentiation from focal autoimmune pancreatitis.

Utility of Contrast-Enhanced Harmonic Endoscopic Ultrasonography for Early Diagnosis of Small Pancreatic Cancer

This study aimed to assess whether contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS), compared to multidetector-row computed tomography (MDCT) and magnetic resonance imaging (MRI), is useful for early diagnosis of small pancreatic cancer (PC). Between March 2010 and June 2018, all three imaging modalities and surgery were performed for patients with a pancreatic solid lesion measuring ≤20 mm; diagnostic ability was compared among modalities. Fifty-one of 60 patients were diagnosed with PC (PC size in 41 patients: 11-20 mm; 10 patients: ≤10 mm). The sensitivity, specificity, and accuracy of CH-EUS, MDCT, and MRI for PC (11-20 mm) detection were 95%/83%/94%, 78%/83%/79%, and 73%/33%/68%, respectively. The diagnostic ability of CH-EUS was significantly superior compared with MDCT and MRI (p = 0.002 and p = 0.007, respectively). The sensitivity, specificity, and accuracy of CH-EUS, MDCT, and MRI for PC (≤10 mm) detection were 70%/100%/77%, 20%/100%/38%, and 50%/100%/62%, respectively. The diagnostic ability of CH-EUS tended to be superior to that of MDCT (p = 0.025). The sensitivity of MDCT for PC (≤10 mm) detection was significantly lower than that for PC (11-20 mm) detection (20% vs. 78%; p = 0.001). CH-EUS, compared to MDCT and MRI, is useful for diagnosing small PCs.

Contrast-enhanced harmonic endoscopic ultrasonography for the differential diagnosis of pancreatic masses: A systematic review and meta-analysis

Understanding the difference between malignant and benign pancreatic masses is critical in terms of diagnosis, although this is difficult to determine in clinical practice. The contrast-enhanced harmonic endoscopic ultrasound (CH-EUS) technique was introduced in 2010, although, to the best of the authors' knowledge, there has been no systematic review or meta-analysis to date evaluating its diagnostic performance for the differentiation of pancreatic masses. The aim of the present study was to systematically evaluate the diagnostic performance of CH-EUS for the differentiation of pancreatic masses. Search key words and inclusion and exclusion criteria were initially presented. Two independent authors read and extracted the relevant information from the included studies. Disagreements were resolved through discussion with another two experienced authors. Metadisc and Stata software were used for the meta-analysis and the evaluation of bias. A total of 16 studies comprising 1,325 patients were included in this meta-analysis. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio of CH-EUS were used to distinguish between malignant and benign tumors, and the values obtained were 93% [95% confidence interval (CI): 91-94%], 84% (95% CI: 80-87%), 5.58 (95% CI: 3.90-7.97), 0.09 (95% CI: 0.07-0.11) and 72.56 (95% CI: 48.93-107.60), respectively. The area under the summary receiver operating characteristic curve was determined to be 0.96. No publication bias was identified in this meta-analysis. Taken together, these results confirm that CH-EUS has a high accuracy rate for distinguishing between benign and malignant pancreatic space-occupying lesions, and it may therefore be used as an effective diagnostic tool for pancreatic masses.

Efficacy of contrast-enhanced EUS for lymphadenopathy: a prospective multicenter pilot study (with videos)

BACKGROUND AND AIMS

Contrast-enhanced EUS (CE-EUS) allows qualitative and quantitative evaluation based on real-time perfusion imaging and may improve the diagnostic capability. The aim of this study was to evaluate the efficacy of CE-EUS in differentiating malignant from benign lymphadenopathy.

METHODS

Patients undergoing EUS-FNA for abdominal or mediastinal lymphadenopathy were prospectively enrolled. The echofeatures on B-mode EUS and the vascular and enhancement patterns in CE-EUS were qualitatively evaluated. The echo intensity change during 60 seconds in the lymphadenopathy was quantitatively evaluated by time intensity curve (TIC) analysis.

RESULTS

One hundred consecutive patients with 70 malignant and 30 benign lesions were enrolled. The sensitivity, specificity, and accuracy of the qualitative assessment in B-mode EUS were 77%, 17%, and 59%, respectively. When the heterogeneous enhancement was defined as malignancy, the sensitivity, specificity, and accuracy of the qualitative assessment in CE-EUS were 67%, 87%, and 73%, respectively. In TIC analysis, the velocity of reduction for homogeneous lesions showed a significant difference between malignant and benign lesions (P = .0011), and the receiver operating characteristic analysis showed an optimal cut-off value of .149 dB/s. The sensitivity, specificity, and diagnostic capabilities of CE-EUS for malignancy were improved to 89%, 77%, and 85%, respectively, on combining the qualitative and quantitative analyses. With regard to diagnostic accuracy, CE-EUS with combined qualitative and quantitative analyses was significantly higher than those of B-mode EUS or qualitative assessment of CE-EUS.

CONCLUSIONS

CE-EUS with the combined qualitative and quantitative analyses for lymphadenopathy might be useful to complement regular EUS and EUS-FNA. (Clinical trial registration number: UMIN000024298.).

Endoscopic Ultrasound for Early Diagnosis of Pancreatic Cancer

Detection of small pancreatic cancers, which have a better prognosis than large cancers, is needed to reduce high mortality rates. Endoscopic ultrasound (EUS) is the most sensitive imaging modality for detecting pancreatic lesions. The high resolution of EUS makes it particularly useful for detecting small pancreatic lesions that may be missed by other imaging modalities. Therefore, EUS should be performed in patients with obstructive jaundice in whom computed tomography (CT) or magnetic resonance imaging (MRI) does not identify a definite pancreatic lesion. Interest in the use of EUS for screening individuals at high risk of pancreatic cancer, including those with intraductal papillary mucinous neoplasms (IPMNs) and familial pancreatic cancer is growing. Contrast-enhanced EUS can facilitate differential diagnosis of small solid pancreatic lesions as well as malignant cystic lesions. In addition, EUS-guided fine needle aspiration can provide samples of small pancreatic lesions. Thus, EUS and EUS-related techniques are essential for early diagnosis of pancreatic cancer.

Contrast-Enhanced EUS for Differential Diagnosis of Pancreatic Masses: A Meta-Analysis

BACKGROUND

Though methods for the diagnosis of pancreatic masses are various, such as ultrasonography (US), computed tomography (CT), endoscopic ultrasonography (EUS), and contrast-enhanced computed tomography (CE-CT), their sensitivity, specificity, and accuracy are not quite satisfying. Contrast-enhanced endoscopic ultrasonography (CE-EUS), as a new technique, has its own unique advantages in diagnosing pancreatic disease. However, its sensitivity, specificity, and accuracy are still controversial.

OBJECTIVE

To evaluate the accuracy of CE-EUS for differential diagnosis between benign and malignant pancreatic mass lesions.

DESIGN

Eighteen relevant articles systemically searched from PubMed, Web of Science, Ovid, Scopus, and MEDLINE were selected. The pooled results were calculated in a fixed effects model.

MAIN OUTCOME MEASUREMENT

The pooled sensitivity, specificity, positive likelihood ratio (LR), negative likelihood ratio, diagnostic odds ratio (OR), and summary receiver operating characteristic (SROC) curve.

RESULTS

The pooled sensitivity, specificity, and diagnostic odds ratio of CE-EUS for the differential diagnosis of pancreatic adenocarcinomas were 0.91 (95% confidence interval (CI), 0.89-0.93), 0.86 (95% CI, 0.83-0.89), and 69.50 (95% CI, 48.89-98.80), respectively. The SROC area under the curve was 0.9545. The subgroup analysis based on excluding the outliers showed that the heterogeneity was eliminated and the pooled sensitivity and specificity were 0.92 (95% CI, 0.90-0.93) and 0.87 (95% CI, 0.84-0.89), respectively. The SROC area under the curve was 0.9569.

CONCLUSION

CE-EUS is a useful method to distinguish pancreatic adenocarcinoma from other pancreatic diseases. Compared with EUS elastography, it has higher specificity. However, it is still not superior to pathological diagnosis for the identification of pancreatic carcinomas.

Value of contrast-enhanced harmonic endoscopic ultrasonography with enhancement pattern for diagnosis of pancreatic cancer: A meta-analysis

BACKGROUND

Current imaging modalities are limited in their ability to distinguish pancreatic cancer (PC) from non-neoplastic pancreatic lesions. The diagnostic use of contrast-enhanced endoscopic ultrasonography (CE-EUS) has increased, and its utility has been reported. Recently, contrast-enhanced harmonic EUS (CH-EUS) was reported to facilitate imaging of parenchymal perfusion and microvessels in pancreatobiliary diseases, leading to a high diagnostic accuracy for PC. The present meta-analysis aims to investigate the usefulness of CH-EUS with enhancement pattern for PC diagnosis.

METHODS

A systematic meta-analysis of all potentially relevant articles identified in PubMed, the Cochrane library, and Medline was carried out. Fixed-effects or random-effects models were used to investigate pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio with 95% confidence interval (CI).

RESULTS

The study enrolled 887 patients from nine eligible studies. Pooled estimates of sensitivity and specificity were 93% (95% CI, 0.91-0.95) and 80% (95% CI, 0.75-0.85), respectively. Subgroup analyses were carried out on the main results after excluding two outliers. Area under summary receiver operating characteristics curve was 0.97. No publication bias was found using funnel plots. No significant relationship was found between the diagnostic odds ratios and the characteristics of the studies including continent and contrast agent.

CONCLUSIONS

This meta-analysis showed that CH-EUS with qualitative analysis of enhancement pattern is useful for the diagnosis of PC, and has high sensitivity and accuracy, regardless of the type of contrast agent used. This modality may provide improved diagnostic accuracy for PC in clinical practice.

Instant evaluation of contrast enhanced endoscopic ultrasound helps to differentiate various solid pancreatic lesions in daily routine

BACKGROUND

Contrast enhanced harmonic endoscopic ultrasound (CEH-EUS) is a spreading technique; some studies have shown its value in the diagnosis of pancreatic adenocarcinoma using quantitative analysis.

AIM

To examine the value of CEH-EUS for differentiating various pancreatic lesions in everyday routine with qualitative and quantitative analysis.

METHODS

Data of 55 patients with pancreatic lesions who underwent CEH-EUS were analysed retrospectively. Perfusion characteristics were classified by the investigator qualitatively immediately upon investigation, quantitative analysis was performed later on. Samples from fine needle aspiration (EUS-FNA) or surgical specimen served as gold standard.

RESULTS

CEH-EUS showed 39 hypoenhanced lesions, 3 non-enhanced and 13 hyperenhanced lesions. Concordance of the investigators qualitative classification of peak contrast enhancement with quantitative analysis later on was 100%, while other parameters such as arrival time, time to peak or area under the curve did not show additional value. 34 of 39 hypoenhanced lesions were pancreatic adenocarcinoma; of the hyperenhanced lesions 4 were inflammatory, 3 neuroendocrine carcinomas, 1 lymphoma, 1 insulinoma and 4 metastases (2 of renal cell carcinoma, 2 of lung cancer). Non-enhanced lesions showed up as necroses. Sensitivity for the detection of pancreatic adenocarcinoma was 100%, specificity 87.2% for hypoenhancement alone; in otherwise healthy pancreatic tissue all hypoenhanced lesions were pancreatic adenocarcinoma (sensitivity and specificity 100%, PPV and NPV for adenocarcinoma 100%).

CONCLUSION

This study again shows the excellent value of CEH-EUS in everyday routine for diagnostics of various focal pancreatic lesions suggesting that qualitatively assessed hypoenhancement is highly predictive for adenocarcinoma. Additional quantitative analysis of perfusion parameters does not add diagnostic yield. In case of the various hyperenhanced pancreatic lesions in our data set, histologic sampling is essential for further treatment.

Impact of endoscopic ultrasonography on diagnosis of pancreatic cancer

Accumulated evidence has revealed that endoscopic ultrasonography (EUS) has had a great impact on the clinical evaluation of pancreatic cancers. EUS can provide high-resolution images of the pancreas with a quality regarded as far surpassing that achieved on transabdominal ultrasound (US), computed tomography (CT), or magnetic resonance imaging (MRI). EUS is particularly useful for the detection of small pancreatic lesions, while EUS and its related techniques such as contrast-enhanced EUS (CE-EUS), EUS elastography, and EUS-guided fine needle aspiration (EUS-FNA) are also useful in the differential diagnosis of solid or cystic pancreatic lesions and the staging (T-staging, N-staging, and M-staging) of pancreatic cancers. In the diagnosis of pancreatic lesions, CE-EUS and EUS elastography play a complementary role to conventional EUS. When sampling is performed using EUS-FNA, CE-EUS and EUS elastography provide information on the target lesions. Thus, conventional EUS, CE-EUS, EUS elastography, and EUS-FNA are essential in the clinical investigation of pancreatic cancer.

An Extragastrointestinal Stromal Tumor Originating from the Pancreas

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal neoplasm of the gastrointestinal tract (GIT). In fewer than 5% of cases, GIST originates primarily from outside the GIT. The occurrence of GIST originating from the pancreas is rare. Sometimes, neuroendocrine tumors should be differentiated from GISTs because of their hyperenhancing nature in radiologic images. We report a case of GIST arising in the pancreas that was confirmed by surgical resection.

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.

Contrast-enhanced endoscopic ultrasound for differential diagnosis of pancreatic cancer: an updated meta-analysis

Aim

We aim to assess the diagnostic value of contrast-enhanced endoscopic ultrasound (CE-EUS) for pancreatic cancer and inflammatory lesions by pooling current evidence.

Materials and Methods

A systematical search of PubMed, Web of Science and the Cochrane Library was performed from inception to January 2016. Two authors independently screened and extracted detailed data from included studies. A random effect model was adopted to estimate the pooled sensitivity, specificity in order to determine the diagnostic ablitity of CE-EUS. Furthermore, we conducted the meta-regression and subgroup analyses to explore possible heterogeneity.

Results

Eighteen eligible studies enrolling 1668 patients were finally included in the study. The pooled sensitivity of CE-EUS for distinguishing pancreatic cancers from solid inflammatory masses was 0.93 (95% CI, 0.91–0.94), and the specificity was 0.88 (95% CI, 0.84–0.90). The area under summary receiver operating characteristic curve yielded 0.97. No publication bias was observed by Deeks’ funnel plot in current meta-analysis.

Conclusions

We provided evidence that CE-EUS is a promising modality for differential diagnosis of pancreatic adenocarcinomas. Further multicenter prospective studies should be carried out to certify its utility.

Imaging modalities in the diagnosis of pancreatic adenocarcinoma: A systematic review and meta-analysis of sensitivity, specificity and diagnostic accuracy

BACKGROUND

Pancreatic cancer, primarily pancreatic ductal adenocarcinoma (PDAC), accounts for 2.4% of cancer diagnoses and 5.8% of cancer death annually. Early diagnoses can improve 5-year survival in PDAC. The aim of this systematic review was to determine the sensitivity, specificity and diagnostic accuracy values for MRI, CT, PET&PET/CT, EUS and transabdominal ultrasound (TAUS) in the diagnosis of PDAC.

METHODS

A systematic review was undertaken to identify studies reporting sensitivity, specificity and/or diagnostic accuracy for the diagnosis of PDAC with MRI, CT, PET, EUS or TAUS. Proportional meta-analysis was performed for each modality.

RESULTS

A total of 5399 patients, 3567 with PDAC, from 52 studies were included. The sensitivity, specificity and diagnostic accuracy were 93% (95% CI=88-96), 89% (95% CI=82-94) and 90% (95% CI=86-94) for MRI; 90% (95% CI=87-93), 87% (95% CI=79-93) and 89% (95% CI=85-93) for CT; 89% (95% CI=85-93), 70% (95% CI=54-84) and 84% (95% CI=79-89) for PET; 91% (95% CI=87-94), 86% (95% CI=81-91) and 89% (95% CI=87-92) for EUS; and 88% (95% CI=86-90), 94% (95% CI=87-98) and 91% (95% C=87-93) for TAUS.

CONCLUSION

This review concludes all modalities, except for PET, are equivalent within 95% confidence intervals for the diagnosis of PDAC.

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.

Differential diagnosis between intraductal papillary mucinous neoplasm with an associated invasive carcinoma and pancreatic ductal adenocarcinoma on ultrasonography: the utility of echo intensity and contrast enhancement

Purpose

The aim of this study was to investigate the utility of echo intensity and contrast enhancement in the differential diagnosis between intraductal papillary mucinous neoplasm with an associated invasive carcinoma (IPMN-IC) and pancreatic ductal adenocarcinoma (PDAC) on ultrasonography.

Methods

This study included eight and 37 patients who had pathologically confirmed IPMN-IC and PDAC, respectively, and were enrolled for a comparative analysis of the sonographic features of the tumors. In the quantitative echo intensity evaluation, the two groups were compared with respect to the difference between the tumor intensity and the pancreatic intensity (TI-PI) and between the tumor intensity and the vascular intensity (TI-VI). In the quantitative contrast enhancement evaluation, the increase in echo intensity (ΔTI) and increase in echo intensity per unit of time (slope) were compared between the groups. The echo intensity and contrast enhancement were also compared between the two groups in patients with T3-T4 disease. In addition, the correlations of the histological type, tumor size, stromal type, and T factor with echogenicity and contrast enhancement were analyzed.

Results

IPMN-IC had significantly greater echo intensity and contrast enhancement than PDAC (TI-PI, P=0.004; TI-VI, P=0.001; ΔTI, P=0.012; slope, P=0.002). In T3-T4 disease, IPMN-IC also showed greater echo intensity and faster enhancement than PDAC. Echo intensity and contrast enhancement were correlated with histological type (TI-PI, P=0.003; TI-VI, P<0.001; ΔTI, P=0.007; slope, P<0.001).

Conclusion

IPMN-IC and PDAC can be differentiated by the quantitative evaluation of echo intensity and contrast enhancement.

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.

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.

Endoscopic ultrasound in the diagnosis and management of carcinoma pancreas

Endoscopic ultrasound (EUS) has become an important component in the diagnosis and treatment of carcinoma pancreas. With the advent of advanced imaging techniques and tissue acquisition methods the role of EUS is becoming increasingly important. Small pancreatic tumors can be reliably diagnosed with EUS. EUS guided fine needle aspiration establishes diagnosis in some cases. EUS plays an important role in staging of carcinoma pancreas and in some important therapeutic methods that include celiac plexus neurolysis, EUS guided biliary drainage and drug delivery. In this review we attempt to review the role of EUS in diagnosis and management of carcinoma pancreas.

Endoscopic ultrasound in the diagnosis and management of carcinoma pancreas

Endoscopic ultrasound (EUS) has become an important component in the diagnosis and treatment of carcinoma pancreas. With the advent of advanced imaging techniques and tissue acquisition methods the role of EUS is becoming increasingly important. Small pancreatic tumors can be reliably diagnosed with EUS. EUS guided fine needle aspiration establishes diagnosis in some cases. EUS plays an important role in staging of carcinoma pancreas and in some important therapeutic methods that include celiac plexus neurolysis, EUS guided biliary drainage and drug delivery. In this review we attempt to review the role of EUS in diagnosis and management of carcinoma pancreas.

Efficacy of contrast-enhanced harmonic endoscopic ultrasonography in the diagnosis of pancreatic ductal carcinoma

BACKGROUND/AIMS

Distinguishing pancreatic ductal carcinoma (DC) from other pancreatic masses remains challenging. This study aims at evaluating the efficacy of contrast-enhanced harmonic endoscopic ultrasonography (CEH-EUS) in the diagnosis of DC.

PATIENTS AND METHODS

Forty-nine patients with solid pancreatic mass lesions underwent CEH-EUS. EUS (B-mode) was used to evaluate the inner echoes, distributions, and borders of the masses. The vascular patterns of the masses were evaluated with CEH-EUS at 30-50 s (early phase) and 70-90 s (late phase) after the administration of Sonazoid®.

RESULTS

The final diagnoses included DCs (37), mass-forming pancreatitis (6), endocrine neoplasms (3), a solid pseudopapillary neoplasm (1), a metastatic carcinoma (1), and an acinar cell carcinoma (1). The sensitivity, specificity, and accuracy of the diagnoses of DC in hypoechoic masses using EUS (B-mode) were 89.2%, 16.7%, and 71.4%, respectively. The sensitivity, specificity, and accuracy for the diagnosis of DC in hypovascular masses using CEH-EUS were 73.0%, 91.7%, and 77.6% in the early phase and 83.8%, 91.7%, and 85.7% in the late phase, respectively.

CONCLUSIONS

CEH-EUS for the diagnosis of DC is superior to EUS. CEH-EUS in the late phase was particularly efficacious in the diagnosis of DC.

Conventional versus contrast-enhanced harmonic endoscopic ultrasonography-guided fine-needle aspiration for diagnosis of solid pancreatic lesions: A prospective randomized trial

OBJECTIVES

Contrast-enhanced harmonic endoscopic ultrasonography (CEH-EUS) has been used to diagnose solid pancreatic lesions (SPLs). The aim of this study was to investigate the efficacy of CEH-EUS-guided fine-needle aspiration (CEH-EUS-FNA) compared with that of conventional EUS-FNA for the diagnosis of SPLs.

METHODS

Forty patients with solid pancreatic lesions who visited Fukushima Medical University between September 2013 and June 2014 were recruited for this prospective study. Twenty patients underwent CEH-EUS-FNA, and 20 patients underwent conventional EUS-FNA. The sampling rate, sensitivity, accuracy, and number of needle passes required to obtain sufficient samples were compared between the two groups.

RESULTS

Patient characteristics, sampling rate, accuracy, and sensitivity were not significantly different between the two groups. The final diagnosis of patients who underwent CEH-EUS-FNA was pancreatic cancer in 19 and intraductal papillary mucinous carcinoma in one. Nineteen patients who underwent conventional EUS-FNA were finally diagnosed with pancreatic cancer and one was diagnosed as cancer of the common bile duct. There was a significant difference in the number of needle passes required. A sufficient sample was obtained on one needle pass in 60% (12/20) of CEH-EUS-FNA group compared with 25% (5/20) of the conventional EUS-FNA group.

CONCLUSIONS

Fewer needle passes were required to obtain samples from solid pancreatic lesions using CEH-EUS-FNA than those required using conventional EUS-FNA. Therefore, CEH-EUS-FNA may be more efficient and safer than conventional EUS-FNA for the diagnosis of solid pancreatic lesions.

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

BACKGROUND

The negative predictive value of endoscopic ultrasonography-guided fine needle aspiration for the diagnosis of solid pancreatic lesions remains low, and the biopsy specimens are sometimes inadequate for appropriate pathological diagnosis.

AIMS

To evaluate the usefulness of a novel method of contrast-enhanced harmonic endoscopic ultrasonography-guided fine-needle aspiration for the differential diagnosis and adequate sampling of solid pancreatic lesions.

METHODS

Patients with a diagnosis of solid pancreatic lesions who underwent fine-needle aspiration guided by contrast-enhanced harmonic endoscopic ultrasonography or by endoscopic ultrasonography from October 2010 to July 2013 were retrospectively identified and classified into the CH-EUS or EUS group, respectively. Surgical pathology and/or follow-up results were defined as the final diagnosis. Operating characteristics and adequacy of biopsy specimens by fine-needle aspiration were compared between the two groups.

RESULTS

Operating characteristics for contrast-enhanced harmonic endoscopic ultrasonography-guided fine-needle aspiration in solid pancreatic lesions were as follows: area under the curve = 0.908, sensitivity = 81.6%, specificity = 100%, positive predictive value = 100%, negative predictive value = 74.1%, and accuracy = 87.9%. The percentage of adequate biopsy specimens in the CH-EUS group (96.6%) was greater than that in the EUS group (86.7%).

CONCLUSION

Simultaneous contrast-enhanced harmonic endoscopic ultrasonography during fine-needle aspiration is useful for improving the diagnostic yield and adequate sampling of solid pancreatic lesions.

Impact of inconclusive endoscopic ultrasound-guided fine-needle aspiration results in the management and outcome of patients with solid pancreatic masses

BACKGROUND AND AIM

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) can be inconclusive in diagnosing solid pancreatic masses. The aim of the present study was to evaluate the impact of an inconclusive EUS-FNA in the management of patients with solid pancreatic masses.

METHODS

This is a retrospective analysis of a prospective database of patients with solid pancreatic masses referred for EUS-FNA between December 2011 and December 2013. Consecutive patients with inconclusive initial EUS-FNA were included. Demographic, clinical, procedural and outcome data were analyzed.

RESULTS

Over the study period, 387 patients underwent EUS-FNA of solid pancreatic masses, of which 38 patients had inconclusive cytology. Of the 38 patients, 18 were categorized as atypical, two were categorized as indeterminate or suspicious for malignancy, and 18 were categorized as benign process. Subsequently, 24 (63.2%) patients achieved cytopathological diagnosis by repeat EUS-FNA (8), transcutaneous FNA (4) and surgery (12). Repeat EUS-FNA were done a median of 13 days after the index examination and resulted in conclusive diagnosis in 72.7% of cases. Five patients undergoing surgery were confirmed to have benign lesions. In 14 (36.8%) patients not receiving a positive cytopathological diagnosis, 11 were eventually confirmed to be malignant based on clinical outcome and imaging evidence.

CONCLUSIONS

Inconclusive EUS-FNA could lead to unnecessary surgical procedures in patients with resectable solid pancreatic masses if no cytopathological diagnosis is obtained through either repeat or alternative diagnostic modalities. Repeat EUS-FNA provided a conclusive diagnosis in a majority of cases, and therefore should be strongly considered ahead of other modalities.

Contrast-enhanced endoscopic ultrasonography: advance and current status

Endoscopic ultrasonography (EUS) technology has undergone a great deal of progress along with the color and power Doppler imaging, three-dimensional imaging, electronic scanning, tissue harmonic imaging, and elastography, and one of the most important developments is the ability to acquire contrast-enhanced images. The blood flow in small vessels and the parenchymal microvasculature of the target lesion can be observed non-invasively by contrast-enhanced EUS (CE-EUS). Through a hemodynamic analysis, CE-EUS permits the diagnosis of various gastrointestinal diseases and differential diagnoses between benign and malignant tumors. Recently, mechanical innovations and the development of contrast agents have increased the use of CE-EUS in the diagnostic field, as well as for the assessment of the efficacy of therapeutic agents. The advances in and the current status of CE-EUS are discussed in this review.