Comparison of endoscopic ultrasound-guided fine needle aspiration for focal pancreatic lesions in patients with normal parenchyma and chronic pancreatitis

Identification of Endosonographic Features that Compromise EUS-FNB Diagnostic Accuracy in Pancreatic Masses

BACKGROUND

Endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) is highly accurate for diagnosing pancreatic mass. However, making diagnosis is challenging in 5-20% of patients. This study investigated the challenging features associated with reduced diagnostic performance in EUS-FNB and potential rescue methods that can improve the diagnostic rate.

METHODS

This single-center retrospective study included patients with solid pancreatic tumors who underwent EUS-FNB between January 1, 2019, and December 12, 2021. Patients without a computed tomography (CT) scan or definite diagnosis were excluded. Challenging features were features that reduced diagnostic accuracy in EUS-FNB, as determined through multivariate analysis. Rescue methods were methods that assisted operators in assessing lesions in patients with challenging features.

RESULTS

Of 332 enrolled patients, an accurate diagnosis obtained using EUS-FNB was achieved in 286 (86.1%). Univariable analysis revealed that the diagnostic accuracy was lower in cases of pancreatic tumors with isoattenuation in CT images (77.3% vs. 89.8%, odds ratio [OR]: 0.39, p = 0.003), an ill-defined margin on EUS (61.2% vs. 92.5%, OR: 0.13, p < 0.001), or tumor size < 20 mm (65.5% vs. 88.1%, OR: 0.26, p = 0.002). However, only ill-defined margins on EUS (OR: 0.14, p < 0.001) and tumor size < 20 mm (OR: 0.25, p = 0.005) were independent predictors of inconclusive EUS-FNB in the multivariate analysis. The use of contrast (OR: 4.46, p = 0.026) and a highly experienced endosonographer (> 5cases/month; OR: 3.25, p = 0.034) improved diagnostic performance in difficult cases.

CONCLUSIONS

Pancreatic tumors with ill-defined tumor margins on EUS or size < 20 mm are challenging features in EUS-FNB. The use of contrast and a highly experienced endosonographer can improve diagnostic performance in difficult cases.

Comparative Assessment of Endoscopic Ultrasound-Guided Biopsies vs. Percutaneous Biopsies of Pancreatic Lesions: A Systematic Review and Meta-Analysis of Diagnostic Performance

Introduction: Pancreatic cancer ranks as the fourth deadliest form of cancer. However, it is essential to note that not all pancreatic masses signal primary malignancy. Therefore, it is imperative to establish the correct differential diagnosis, a process further supported by pre-operative biopsy procedures. This meta-analysis aims to compare the diagnostic performance of two minimally invasive biopsy approaches for pancreatic tissue sampling: percutaneous biopsies guided by computed tomography or ultrasound, and transduodenal biopsies guided by endoscopic ultrasound (EUS). Methods: A systematic literature search was conducted in the MEDLINE and Scopus databases. The included studies analyzed the diagnostic performance of the two biopsy methods, and they were assessed for risk of bias using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Statistical analysis was carried out using the RevMan and MetaDisc software packages. Results: The statistical analysis of the results demonstrated the superiority of the percutaneous approach. Specifically, the pooled sensitivity, specificity, LR+, LR-and DOR for the percutaneous approach were 0.896 [95% CI: 0.878-0.913], 0.949 [95% CI: 0.892-0.981], 9.70 [95% CI: 5.20-18.09], 0.20 [95% CI: 0.12-0.32] and 68.55 [95% CI: 32.63-143.98], respectively. The corresponding values for EUS-guided biopsies were 0.806 [95% CI: 0.775-0.834], 0.955 [95% CI: 0.926-0.974], 12.04 [95% CI: 2.67-54.17], 0.24 [95% CI: 0.15-0.39] and 52.56 [95% CI: 13.81-200.09], respectively. Nevertheless, it appears that this statistical superiority is also linked to the selection bias favoring larger and hence more readily accessible tumors during percutaneous biopsy procedures. Conclusions: Concisely, our meta-analysis indicates the statistical superiority of the percutaneous approach. However, selecting the optimal biopsy method is complex, influenced by factors like patient and tumor characteristics, clinical resources, and other relevant considerations.

Role of Endoscopic Ultrasound in the Management of Pancreatic Cancer

Pancreatic cancer is one of the common causes of cancer-associated mortality with a dismal overall prognosis which has remained virtually unchanged over decades. In the present era, the management of patients with pancreatic cancer involves a multi-disciplinary team of radiologists, gastroenterologists, surgical oncologists, medical oncologists, radiation oncologists and other specialists. The advancement of interventional endoscopy has made a significant impact in the management of pancreatic cancers. Since the inception of endoscopic ultrasound, it has evolved over the last few decades in the management of pancreatic malignancies and its role in staging and tissue acquisition is well established. There is an emerging role of endoscopic ultrasound in the treatment and palliation of unresectable pancreatic cancer. The aim of this article is to review the role of endoscopic ultrasound in diagnostic and therapeutic interventions in the current era.

The clinical characteristics of focal acute pancreatitis based on imaging diagnosis: comparison with non-localized acute pancreatitis- a preliminary result

BACKGROUND

Focal acute pancreatitis is a special type of acute pancreatitis, which diagnosis is based on image showing a focal mass formation in the pancreas. For acute pancreatitis with or without focal inflammatory enlargement, little is known on differences between them. Our purpose was to find differences between focal acute pancreatitis and non-localized acute pancreatitis.

METHODS

We reviewed the medical records of a total of 24 patients diagnosed with focal acute pancreatitis by imaging and clinical diagnosis, and 27 cases of acute pancreatitis which manifest non-localized pancreas inflammation were selected as the control group. The differences of the two groups were compared to describe their clinical characteristics.

RESULTS

Differences in bloating (4.2% VS 29.6%,P = 0.026), abdominal tenderness (58.3% VS 85.2%,P = 0.032), peripheral blood neutrophil ratio (60.1 ± 23.3VS 75.9 ± 12.6,P = 0.004), serum D-Dimer (0.40(0.25,0.98) VS 1.59(0.49,4.63),P = 0.008), serum GGT (40(25,91) VS120(22,383),P = 0.046), serum amylase(435(241,718) VS 591(394,1333),P = 0.044) and lipase(988(648,1067) VS 1686(525,2675),P = 0.027) between focal acute pancreatitis and non-localized acute pancreatitis groups were statistically significant. However, difference of the severity of two groups was not statistically significant (P = 1.000).

CONCLUSION

Compared with non-localized acute pancreatitis, changes in symptoms, signs and laboratory indicators of focal acute pancreatitis are non-obvious, however, there was no significant difference in the severity of two groups, indicating that we should pay more attention to diagnosis of focal acute pancreatitis in clinical practice.

Pancreatic tail cancer in the setting of pancreatitis with a review of the literature: A case report

Environmental risk factors for pancreatic cancer include acute and chronic pancreatitis, obesity, and tobacco use. Differentiating a pancreatic neoplasm in a patient with pancreatitis can be challenging due to their similar presentations. A 57-year-old African American man with a history of congestive heart failure, pancreatitis, and incomplete pancreas divisum presented with an epigastric abdominal pain that radiated to his back. Imaging showed necrotizing pancreatitis, a developing splenic infarct, and a mass at the pancreas tail. The patient was discharged with pain medications and was recommended follow-up imaging after resolution of his pancreatitis. He was readmitted to the emergency department 2 weeks later with recurrent acute abdominal pain. Computed tomography scan of abdomen and pelvis followed by magnetic resonance imaging and endoscopic ultrasound revealed an infiltrative pancreatic tail mass. Biopsy of the mass confirmed a locally advanced pancreatic tail adenocarcinoma. Chronic pancreatitis is associated with pancreatic cancer. Practitioners should be aware of the co-existence of chronic pancreatitis and pancreatic cancer, and the initial steps to evaluate a malignancy in chronic pancreatitis.

A primer on artificial intelligence in pancreatic imaging

Artificial Intelligence (AI) is set to transform medical imaging by leveraging the vast data contained in medical images. Deep learning and radiomics are the two main AI methods currently being applied within radiology. Deep learning uses a layered set of self-correcting algorithms to develop a mathematical model that best fits the data. Radiomics converts imaging data into mineable features such as signal intensity, shape, texture, and higher-order features. Both methods have the potential to improve disease detection, characterization, and prognostication. This article reviews the current status of artificial intelligence in pancreatic imaging and critically appraises the quality of existing evidence using the radiomics quality score.

Approach to Pancreatic Head Mass in the Background of Chronic Pancreatitis

Chronic pancreatitis (CP) is a known risk factor for pancreatic cancer. CP may present with an inflammatory mass, and differentiation from pancreatic cancer is often difficult. Clinical suspicion of malignancy dictates a need for further evaluation for underlying pancreatic cancer. Imaging modalities remain the mainstay of evaluation for a mass in background CP; however, they have their shortcomings. Endoscopic ultrasound (EUS) has become the go-to investigation. Adjunct modalities such as contrast-harmonic EUS and EUS elastography, as well as EUS-guided sampling using newer-generation needles are useful in differentiating inflammatory from malignant masses in the pancreas. Paraduodenal pancreatitis and autoimmune pancreatitis often masquerade as pancreatic cancer. In this narrative review, we discuss the various modalities used to differentiate inflammatory from malignant masses of the pancreas.

Approach to Pancreatic Head Mass in the Background of Chronic Pancreatitis

Chronic pancreatitis (CP) is a known risk factor for pancreatic cancer. CP may present with an inflammatory mass, and differentiation from pancreatic cancer is often difficult. Clinical suspicion of malignancy dictates a need for further evaluation for underlying pancreatic cancer. Imaging modalities remain the mainstay of evaluation for a mass in background CP; however, they have their shortcomings. Endoscopic ultrasound (EUS) has become the go-to investigation. Adjunct modalities such as contrast-harmonic EUS and EUS elastography, as well as EUS-guided sampling using newer-generation needles are useful in differentiating inflammatory from malignant masses in the pancreas. Paraduodenal pancreatitis and autoimmune pancreatitis often masquerade as pancreatic cancer. In this narrative review, we discuss the various modalities used to differentiate inflammatory from malignant masses of the pancreas.

The value of artificial intelligence techniques in predicting pancreatic ductal adenocarcinoma with EUS images: A meta-analysis and systematic review

Conventional EUS plays an important role in identifying pancreatic cancer. However, the accuracy of EUS is strongly influenced by the operator's experience in performing EUS. Artificial intelligence (AI) is increasingly being used in various clinical diagnoses, especially in terms of image classification. This study aimed to evaluate the diagnostic test accuracy of AI for the prediction of pancreatic cancer using EUS images. We searched the Embase, PubMed, and Cochrane Library databases to identify studies that used endoscopic ultrasound images of pancreatic cancer and AI to predict the diagnostic accuracy of pancreatic cancer. Two reviewers extracted the data independently. The risk of bias of eligible studies was assessed using a Deek funnel plot. The quality of the included studies was measured by the QUDAS-2 tool. Seven studies involving 1110 participants were included: 634 participants with pancreatic cancer and 476 participants with nonpancreatic cancer. The accuracy of the AI for the prediction of pancreatic cancer (area under the curve) was 0.95 (95% confidence interval [CI], 0.93-0.97), with a corresponding pooled sensitivity of 93% (95% CI, 0.90-0.95), specificity of 90% (95% CI, 0.8-0.95), positive likelihood ratio 9.1 (95% CI 4.4-18.6), negative likelihood ratio 0.08 (95% CI 0.06-0.11), and diagnostic odds ratio 114 (95% CI 56-236). The methodological quality in each study was found to be the source of heterogeneity in the meta-regression combined model, which was statistically significant (P = 0.01). There was no evidence of publication bias. The accuracy of AI in diagnosing pancreatic cancer appears to be reliable. Further research and investment in AI could lead to substantial improvements in screening and early diagnosis.

Endoscopic Ultrasound Guided Fine-Needle Aspiration for Solid Lesions in Chronic Pancreatitis: A Systematic Review and Meta-Analysis

BACKGROUND

Patients with chronic pancreatitis (CP) are at a higher risk of developing pancreatic adenocarcinoma compared the general population with an estimated 5% risk of developing pancreatic cancer in 20 years. Endoscopic ultrasound fine needle aspiration (EUS-FNA) of solid pancreatic lesions (SPL) has an excellent sensitivity (85-90%) and specificity (98-100%) for diagnosing pancreatic malignancy. However, data on the performance characteristics of EUS-FNA in CP are mixed.

AIMS

In this systematic review and meta-analysis, we aim to examine data from published studies on the diagnostic performance of EUS-FNA in detecting pancreatic malignancy in CP.

METHODS

We conducted a comprehensive search of MEDLINE, Cochrane, EMBASE, Scopus databases for studies published in English language that reported performance characteristics of EUS-FNA for SPL up to November 2020. Two reviewers independently conducted screening, full text review and data extraction according to the PRISMA guidelines. Quality of included studies was assessed using the risk of bias in non-randomized studies of interventions (ROBINS-I) tool. The parameters of interest were sensitivity, specificity, negative, and positive likelihood ratios. Cochran Q test and I statistics were used to determine the between-study heterogeneity. Funnel plots were used to describe publication bias.

RESULTS

A total of 6753 studies were identified on initial search. Studies that reported EUS-FNA of cystic pancreas lesions were excluded. Eight studies met the inclusion criteria. Seven studies were retrospective, and one was prospective. A total of 593 patients with CP underwent EUS-FNA for SPL. The pooled sensitivity of EUS-FNA was 65% (95% CI 52.6-75.6%, I2 = 44%), specificity was 96.8% (75-99.7%, I2  = 89%), negative likelihood ratio (NLR) 41.4 (11.1-149.6, I2 = 70%), positive likelihood ratio (PLR) 24.1 (2.8-208, I2 = 90%). The pooled data from seven studies that compared 901 non-CP vs. 127 CP showed that the sensitivity of EUS-FNA in diagnosing pancreatic malignancy was 91.5 vs. 65.3% [OR (95% CI) 5.5 (2.9-10.2), I2: 31.8%]. The specificity pooled from six studies [333 non-CP vs. 357 CP] was 95.9% vs. 82.4%, [OR (95% CI) 1.3 (0.2-9.8), I2 = 73%]. The risk of bias was serious in one study, low in four studies and moderate in three studies.

CONCLUSION

This pooled meta-analysis shows a low sensitivity of EUS-FNA in diagnosing malignancy in CP patients with SPL in comparison to patients without CP. Modalities such as EUS-fine needle biopsy have high sensitivity and specificity for diagnosing pancreatic cancer and should be considered in patients with CP and suspected pancreatic malignancy.

Artificial intelligence for pancreatic cancer detection: Recent development and future direction

Artificial intelligence (AI) has been increasingly utilized in medical applications, especially in the field of gastroenterology. AI can assist gastroenterologists in imaging-based testing and prediction of clinical diagnosis, for examples, detecting polyps during colonoscopy, identifying small bowel lesions using capsule endoscopy images, and predicting liver diseases based on clinical parameters. With its high mortality rate, pancreatic cancer can highly benefit from AI since the early detection of small lesion is difficult with conventional imaging techniques and current biomarkers. Endoscopic ultrasound (EUS) is a main diagnostic tool with high sensitivity for pancreatic adenocarcinoma and pancreatic cystic lesion. The standard tumor markers have not been effective for diagnosis. There have been recent research studies in AI application in EUS and novel biomarkers to early detect and differentiate malignant pancreatic lesions. The findings are impressive compared to the available traditional methods. Herein, we aim to explore the utility of AI in EUS and novel serum and cyst fluid biomarkers for pancreatic cancer detection.

Artificial intelligence for early detection of pancreatic adenocarcinoma: The future is promising

Pancreatic ductal adenocarcinoma (PDAC) is a worldwide public health concern. Despite extensive research efforts toward improving diagnosis and treatment, the 5-year survival rate at best is approximately 15%. This dismal figure can be attributed to a variety of factors including lack of adequate screening methods, late symptom onset, and treatment resistance. Pancreatic ductal adenocarcinoma remains a grim diagnosis with a high mortality rate and a significant psy-chological burden for patients and their families. In recent years artificial intelligence (AI) has permeated the medical field at an accelerated pace, bringing potential new tools that carry the promise of improving diagnosis and treatment of a variety of diseases. In this review we will summarize the landscape of AI in diagnosis and treatment of PDAC.

Enhanced EUS imaging (with videos)

BACKGROUND AND AIMS

EUS remains a primary diagnostic tool for the evaluation of pancreaticobiliary disease. Although EUS combined with FNA or biopsy sampling is highly sensitive for the diagnosis of neoplasia within the pancreaticobiliary tract, limitations exist in specific clinical settings such as chronic pancreatitis. Enhanced EUS imaging technologies aim to aid in the detection and diagnosis of lesions that are commonly evaluated with EUS.

METHODS

We reviewed technologies and methods for enhanced imaging during EUS and applications of these methods. Available data regarding efficacy, safety, and financial considerations are summarized.

RESULTS

Enhanced EUS imaging methods include elastography and contrast-enhanced EUS (CE-EUS). Both technologies have been best studied in the setting of pancreatic mass lesions. Robust data indicate that neither technology has adequate specificity to serve as a stand-alone test for pancreatic malignancy. However, there may be a role for improving the targeting of sampling and in the evaluation of peritumoral lymph nodes, inflammatory pancreatic masses, and masses with nondiagnostic FNA or fine-needle biopsy sampling. Further, novel applications of these technologies have been reported in the evaluation of liver fibrosis, pancreatic cysts, and angiogenesis within neoplastic lesions.

CONCLUSIONS

Elastography and CE-EUS may improve the real-time evaluation of intra- and extraluminal lesions as an adjunct to standard B-mode and Doppler imaging. They are not a replacement for EUS-guided tissue sampling but provide adjunctive diagnostic information in specific clinical situations. The optimal clinical use of these technologies continues to be a focus of ongoing research.

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.

Interobserver Reliability of Endoscopic Ultrasonography: Literature Review

Endoscopic ultrasonography (EUS) has been applied to the diagnosis of various digestive disorders. Although it has been widely accepted and its diagnostic value is high, the dependence of EUS diagnosis on image interpretation done by the endosonographer has persisted as an important difficulty. Consequently, high interobserver reliability (IOR) in EUS diagnosis is important to demonstrate the reliability of EUS diagnosis. We reviewed the literature on the IOR of EUS diagnosis for various diseases such as chronic pancreatitis, pancreatic solid/cystic mass, lymphadenopathy, and gastrointestinal and subepithelial lesions. The IOR of EUS diagnosis differs depending on the disease; moreover, EUS findings with high IOR and those with IOR that was not necessarily high were used as diagnostic criteria. Therefore, to further increase the value of EUS diagnosis, EUS diagnostic criteria with high diagnostic characteristics based on EUS findings with high IOR must be established.

EUS-FNA Diagnosis with Core Biopsy of Pancreatic Metastases from Primary Breast Cancer

BACKGROUND

The pancreas as a site of metastasis of other primary tumors is a rare event. Pancreatic metastases may occur years after the start of treatment of a neoplasm of another organ or may be the initial manifestation of an unidentified primary tumor. The most commonly reported primary sites for pancreatic metastases are the kidneys, lungs, breast, bowel, and skin (melanoma). Case Summary. The authors report a case of pancreatic metastasis derived from a primary breast cancer that underwent endoscopic ultrasound fine-needle aspiration (EUS-FNA) core biopsy to obtain tissue, which made it possible to perform an immunohistochemical study.

CONCLUSION

We emphasize the importance of outpatient follow-up after the treatment of a neoplasia and the completion of control exams. In addition, we should always be aware of the finding of a secondary lesion in patients who have already been diagnosed with cancer, even if it is located in unusual organs, as in this case, where two metastases of a breast carcinoma to the pancreas were detected.

O-Glycan-Altered Extracellular Vesicles: A Specific Serum Marker Elevated in Pancreatic Cancer

Pancreatic cancer (PC) is among the most lethal malignancies due to an often delayed and difficult initial diagnosis. Therefore, the development of a novel, early stage, diagnostic PC marker in liquid biopsies is of great significance. In this study, we analyzed the differential glycomic profiling of extracellular vesicles (EVs) derived from serum (two cohorts including 117 PC patients and 98 normal controls) using lectin microarray. The glyco-candidates of PC-specific EVs were quantified using a high-sensitive exosome-counting system, ExoCounter. An absolute quantification system for altered glycan-containing EVs elevated in PC serum was established. EVs recognized by O-glycan-binding lectins ABA or ACA were identified as candidate markers by lectin microarray. Quantitative analyses using ExoCounter revealed that the ABA- or ACA-positive EVs were significantly increased in the culture of PC cell lines or in the serum of PC patients including carbohydrate antigen 19-9 negative patients with high area under curve values. The elevated numbers of EVs in PC serum returned to normal levels after pancreatectomy. Histological examination confirmed that the tumors stained with ABA/ACA. These specific EVs with O-glycans recognized by ABA/ACA are elevated in PC sera and can act as potential biomarkers in a liquid biopsy for PC patients screening.

Chronic pancreatitis: an overview of diagnosis and management

INTRODUCTION

Chronic pancreatitis entails a heavy burden on the healthcare system because of its often protracted evolution, requiring complex diagnostic and therapeutic procedures.

AREAS COVERED

This review focuses on novel imaging and endoscopic diagnostic and therapeutic interventions that have changed the management of patients with chronic pancreatitis. We have conducted an extensive search of original papers and guidelines, in order to provide a comprehensive and up to date review of available evidence in these areas of interest.

EXPERT OPINION

The traditional challenges in managing chronic pancreatitis patients stemmed from the limitations of diagnostic modalities, which could not correctly identify patients in an early stage of the disease, as well as from the scarcity of therapeutic options available. Advances in imaging of CT-scan, MRI, and EUS have opened the way for early diagnosis and staging. This has allowed more aggressive and tailored therapeutic modalities, particularly in endoscopic therapy and minimally invasive surgical interventions. Although high-quality data from large RCTs is still scarce, evidence-based algorithms for diagnosis and therapy are now changing the way we address this chronic disease. In the near future, we can expect a tailored approach based on patient and disease-related predictive factors, relying on a vast armamentarium of endoscopic and surgical solutions.

Diagnostic accuracy of unenhanced CT texture analysis to differentiate mass-forming pancreatitis from pancreatic ductal adenocarcinoma

PURPOSE

To investigate the value of texture analysis on unenhanced computed tomography (CT) to potentially differentiate mass-forming pancreatitis (MFP) from pancreatic ductal adenocarcinoma (PDAC).

METHODS

A retrospective study consisting of 109 patients (30 MFP patients vs 79 PDAC patients) who underwent preoperative unenhanced CT between January 2012 and December 2017 was performed. Synthetic minority oversampling technique (SMOTE) algorithm was adopted to reconstruct and balance MFP and PDAC samples. A total of 396 radiomic features were extracted from unenhanced CT images. Mann-Whitney U test and minimum redundancy maximum relevance (MRMR) methods were used for the purpose of dimension reduction. Predictive models were constructed using random forest (RF) method, and were validated using leave group out cross-validation (LGOCV) method. Diagnostic performance of the predictive model, including sensitivity, specificity, accuracy, positive predicting value (PPV), and negative predicting value (NPV), was recorded.

RESULTS

We applied 200% of SMOTE to MFP and PDAC patients, resulting in 90 MFP patients compared with 120 PDAC patients. Dimension reduction steps yielded 30 radiomic features using Mann-Whitney U test and MRMR methods. Ten radiomic features were retained using RF method. Four most predictive parameters, including GreyLevelNonuniformity_angle90_offset1, VoxelValueSum, HaraVariance, and ClusterProminence_AllDirection_offset1_SD, were used to generate the predictive model with preferable 92.2% sensitivity, 94.2% specificity, 93.3% accuracy, 92.2% PPV, and 94.2% NPV. Finally, in LGOCV analysis, a high pooled mean sensitivity, specificity, and accuracy (82.6%, 80.8%, and 82.1%, respectively) indicate a relatively reliable and stable predictive model.

CONCLUSIONS

Unenhanced CT texture analysis can be a promising noninvasive method in discriminating MFP from PDAC.

Differentiation of focal autoimmune pancreatitis from pancreatic ductal adenocarcinoma

Autoimmune pancreatitis (AIP) is an inflammatory process of the pancreas that occurs most commonly in elderly males and clinically can mimic pancreatic adenocarcinoma and present with jaundice, weight loss, and abdominal pain. Mass-forming lesions in the pancreas are seen in the focal form of AIP and both clinical and imaging findings can overlap those of pancreatic cancer. The accurate distinction of AIP from pancreatic cancer is of utmost importance as it means avoiding unnecessary surgery in AIP cases or inaccurate steroid treatment in patients with pancreatic cancer. Imaging concomitantly with serological examinations (IgG4 and Ca 19-9) plays an important role in the distinction between these entities. Characteristic extra-pancreatic manifestations as well as favorable good response to treatment with steroids are characteristic of AIP. This paper will review current diagnostic parameters useful in differentiating between focal AIP and pancreatic adenocarcinoma.

Qualitative and Quantitative Contrast-enhanced Endoscopic Ultrasound Improves Evaluation of Focal Pancreatic Lesions

BACKGROUND & AIMS

Endoscopic ultrasound (EUS) is a sensitive method to evaluate the pancreas but its diagnostic capability for several diseases is limited. We compared the diagnostic yield of unenhanced EUS with that of contrast-enhanced EUS for focal pancreas lesions and identified and tested quantitative parameters of contrast enhancement.

METHODS

We performed a prospective tandem-controlled trial in which 101 patients with focal pancreas lesions (48 with masses, 28 with cysts, and 25 with pancreatitis) underwent conventional EUS followed by contrast EUS using intravenous perflutren microspheres. The diagnosis at each stage was scored and compared with a standard (findings from surgical pathology analysis, cytologic, and/or 6-month clinical follow-up evaluations). Quantitative parameters were generated by time-intensity curve analysis. Solid lesions were divided into derivation and testing cohorts for a crossover validation analysis of the quantitative parameters. The primary outcome was diagnostic yield of unenhanced vs contrast EUS in analysis of focal pancreas lesions.

RESULTS

Contrast increased the diagnostic yield of EUS from 64% (65/101 lesions accurately assessed) to 91% (92/101 lesions accurately assessed); the odds ratio [OR] was 7.8 (95% CI, 2.7-30.2) for accurate analysis of lesions by contrast-enhanced EUS relative to unenhanced EUS. The contrast increased accuracy of analysis of pancreas masses (OR, 6.0; 95% CI, 1.8-31.8), improving assessment of neuroendocrine and other (non-carcinoma) tumors. Contrast increased the diagnostic yield for pancreas cysts to 96% (27/28) compared with 71.4% (20/28) for unenhanced EUS (P = .02), due to improved differentiation of mural nodules vs debris. Time-intensity curve analysis revealed distinct patterns of relative peak enhancement (rPE) and in-slope (rIS) for different lesions following contrast injection: for adenocarcinomas, values were low rPE and low rIS; for neuroendocrine masses, values were high rPE and normal IS; and for chronic pancreatitis foci, values were normal rPE and low rIS. In the validation cohort, these parameters correctly characterized 91% of lesions and improved yield relative to unenhanced EUS (OR, 10; 95% CI, 1.4-34.0).

CONCLUSIONS

Contrast-enhanced EUS improves the accuracy of analysis of focal pancreas lesions, compared with unenhanced EUS. Integration of practical quantitative parameters, specifically relative peak enhancement and in-slope, might increase the diagnostic accuracy of contrast EUS. ClinicalTrials.gov no: 02863770.

EUS-guided tissue acquisition in chronic pancreatitis: Differential diagnosis between pancreatic cancer and pseudotumoral masses using EUS-FNA or core biopsy

BACKGROUND AND OBJECTIVE

EUS-FNA sensitivity for malignancy in parenchymal masses of patients with concurrent chronic pancreatitis (CP) has been reported to be unsatisfactory. The aim of the present study was to directly compare the diagnostic accuracy of EUS-FNA and EUS-fine-needle biopsy (FNB) in differentiating between inflammatory masses and malignancies in the setting of CP.

METHODS

We performed a retrospective analysis of prospective, multicentric databases of all patients with pancreatic masses and clinico-radiological-endosonographic features of CP who underwent EUS-FNA or FNB.

RESULTS

Among 1124 patients with CP, 210 patients (60% males, mean age: 62.7 years) with CP and pancreatic masses met the inclusion criteria and were enrolled. In the FNA group (110 patients), a correct diagnosis was obtained in all but 18 cases (diagnostic accuracy 83.6%, sensitivity 69.5%, specificity 100%, positive predictive value [PPV] 100%, and negative predictive value [NPV] 73.9%); by contrast, among 100 patients undergoing FNB, a correct diagnosis was obtained in all but seven cases (diagnostic accuracy 93%, sensitivity 86.8%, specificity 100%, PPV 100%, and NPV 87%) (P = 0.03, 0.03, 1, 1, and 0.07, respectively). At binary logistic regression, focal pancreatitis (odds of event occurrence [OR]: 4.9; P < 0.001), higher Ca19-9 (OR: 2.3;P= 0.02), and FNB (OR: 2.5; P < 0.01) were the only independent factors associated with a correct diagnosis.

CONCLUSION

EUS-FNB is effective in the differential diagnosis between pseudotumoral masses and solid neoplasms in CP, showing higher diagnostic accuracy and sensitivity than EUS-FNA. EUS-FNB should be considered the preferred diagnostic technique for diagnosing cancer in the setting of CP.

ACG Clinical Guideline: Chronic Pancreatitis

Chronic pancreatitis (CP) is historically defined as an irreversible inflammatory condition of the pancreas leading to varying degrees of exocrine and endocrine dysfunction. Recently however, the paradigm for the diagnosis has changed in that it breaks with the traditional clinicopathologic-based definition of disease, focusing instead on diagnosing the underlying pathologic process early in the disease course and managing the syndrome more holistically to change the natural course of disease and minimize adverse disease effects. Currently, the most accepted mechanistically derived definition of CP is a pathologic fibroinflammatory syndrome of the pancreas in individuals with genetic, environmental, and/or other risk factors who develop persistent pathologic responses to parenchymal injury or stress. The most common symptom of CP is abdominal pain, with other symptoms such as exocrine pancreatic insufficiency and diabetes developing at highly variable rates. CP is most commonly caused by toxins such as alcohol or tobacco use, genetic polymorphisms, and recurrent attacks of acute pancreatitis, although no history of acute pancreatitis is seen in many patients. Diagnosis is made usually on cross-sectional imaging, with modalities such as endoscopic ultrasonography and pancreatic function tests playing a secondary role. Total pancreatectomy represents the only known cure for CP, although difficulty in patient selection and the complications inherent to this intervention make it usually an unattractive option. This guideline will provide an evidence-based practical approach to the diagnosis and management of CP for the general gastroenterologist.

Features of chronic pancreatitis by endoscopic ultrasound influence the diagnostic accuracy of endoscopic ultrasound-guided fine-needle aspiration of small pancreatic lesions

BACKGROUND AND AIM

In chronic pancreatitis (CP) patients, diagnosis of small pancreatic lesions by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is challenging. Thus, the aim of the present study was to investigate whether CP influences the diagnostic ability of EUS-FNA for pancreatic lesions ≤10 mm.

METHODS

One hundred and seventeen patients who underwent EUS-FNA for pancreatic lesions ≤10 mm in size were enrolled. Patients were classified into two groups based on features of CP observed by EUS (EUS-CP features) in accordance with the Rosemont classification. The CP group was defined as cases consistent with CP or suggestive of CP, and the non-CP group was defined as cases indeterminate for CP or normal. Factors influencing the diagnostic accuracy of EUS-FNA and CP status in pancreatic tumors were also investigated.

RESULTS

Diagnostic ability of EUS-FNA (overall cases, non-CP vs CP) had sensitivity (80.4%, 96.7% vs 57.1%; P < 0.001), specificity (100%, 100% vs 100%; P > 0.05), and accuracy (91.5%, 98.6% vs 80.4%; P = 0.001). In multivariate analysis of factors influencing the accuracy of EUS-FNA, CP significantly lowered the accuracy (P = 0.048; odds ratio [OR] = 9.21). Among pancreatic cancer patients, the number of CP patients was significantly higher than the number of patients with benign lesions (P = 0.023). In multivariate analysis, lobularity without honeycombing was more frequently observed in cases of pancreatic cancer (P = 0.018; OR, 12.65).

CONCLUSION

Endoscopic ultrasound-guided FNA offers high accuracy for small pancreatic lesions ≤10 mm. However, in cases with CP, the diagnostic ability of EUS-FNA is significantly reduced.

Factors affecting cytological results of endoscopic ultrasound guided-fine needle aspiration during learning

Background

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is a standard procedure used to obtain tissue samples for diagnosis of solid retroperitoneal tumours. However, this procedure demands high technical expertise and requires a strong learning curve. Our aim was to identify factors associated with false-negative EUS-FNA results during the learning for endoscopists.

Methods

Our retrospective analysis was based on the EUS-FNA specimens collected by two novice endoscopists in 200 patients with retroperitoneal lesions who had confirmed image- or tissue-based diagnoses of malignancy or benign lesions.

Results

In the first 40 performances endoscopists, the false-negative diagnostic rate of EUS-FNA was higher among patients with chronic pancreatitis than in patients without chronic pancreatitis. Patients who underwent FNA through the trans-duodenal puncture route also had lower success cytological diagnosis rate than through the trans-gastric puncture route. The rate of successful cytological diagnoses with EUS-FNA improved after 40 procedures and was not influenced by chronic pancreatitis presentation or difference puncture route.

Conclusion

Regarding the learning curve, more than 40 procedures were required to achieve a stable success rate of EUS-FNA. Chronic pancreatitis and trans-duodenal puncture route are the predictive factors for a false-negative FNA cytological result during learning.

Trial registration

This was a retrospective study.

Pitfalls in the MDCT of pancreatic cancer: strategies for minimizing errors

Multidetector computed tomography (MDCT) is a widely used cross-sectional imaging modality for initial evaluation of patients with suspected pancreatic ductal adenocarcinoma (PDAC). However, diagnosis of PDAC can be challenging due to numerous pitfalls associated with image acquisition and interpretation, including technical factors, imaging features, and cognitive errors. Accurate diagnosis requires familiarity with these pitfalls, as these can be minimized using systematic strategies. Suboptimal acquisition protocols and other technical errors such as motion artifacts and incomplete anatomical coverage increase the risk of misdiagnosis. Interpretation of images can be challenging due to intrinsic tumor features (including small and isoenhancing masses, exophytic masses, subtle pancreatic duct irregularities, and diffuse tumor infiltration), presence of coexisting pathology (including chronic pancreatitis and intraductal papillary mucinous neoplasm), mimickers of PDAC (including focal fatty infiltration and focal pancreatitis), distracting findings, and satisfaction of search. Awareness of pitfalls associated with the diagnosis of PDAC along with the strategies to avoid them will help radiologists to minimize technical and interpretation errors. Cognizance and mitigation of these errors can lead to earlier PDAC diagnosis and ultimately improve patient prognosis.

The "Twist-Needle" - a new concept for endoscopic ultrasound-guided fine needle-biopsy

Background and study aims  Endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) represents a standard method for tissue acquisition of lesions adjacent to the gastrointestinal wall. Needles of 19 gauge acquire more tissue than needles with a smaller diameter, but are often unable to penetrate solid, rigid masses. In this study we evaluated a novel prototype that links forward movement of the needle to rotation of the needle tip. Materials and methods  Two needle-models that generate either a regular axial movement or a combination of axial movement with rotation of the needle tip were compared ex vivo for measurement of pressure needed to penetrate artificial tissue. Furthermore, a standard 19-gauge EUS-FNB needle was compared to a modified model ("Twist Needle") in an ex vivo model to measure the amount of tissue obtained. Results  Pressure measurements using the rotating needle revealed that significantly less pressure is needed for penetration compared to the regular axial movement (mean ± SEM; 3.7 ± 0.3 N vs. 5.5 ± 0.3 N). Using the modified 19-gauge "Twist Needle" did not diminish tissue acquisition measured by surface amount compared to a standard needle (37 ± 5 mm² vs. 35 ± 6 mm²). Conclusion  The method of rotation of an EUS-FNB needle tip upon forward movement requires less pressure for penetration but does not diminish tissue acquisition. Hence, the concept of our "Twist Needle" may potentially reduce some of the current limitations of standard EUS-FNB.

Role of Endoscopic Ultrasound in Detecting Pancreatic Cancer Missed on Cross-Sectional Imaging in Patients Presenting with Pancreatitis: A Retrospective Review

INTRODUCTION

Pancreatic cancer is the fourth leading cause of cancer-related death in the USA. Early detection of pancreatic cancer may help improve patient survival. It has been hypothesized that acute idiopathic or chronic pancreatitis is associated with an increased risk of pancreatic cancer; however, these conditions may also represent an early manifestation of pancreatic cancer, rather than just being risk factors. Endoscopic ultrasound (EUS) is a sensitive diagnostic modality for the detection of small, early-stage pancreatic tumors. The aim of this study was to evaluate the diagnostic yield of EUS for pancreatic cancer in patients with acute idiopathic or chronic pancreatitis when cross-sectional imaging (CT and/or MRI) was negative for a mass lesion in the pancreas.

METHODS

This study was an IRB-approved retrospective chart review conducted for the period of August 2005 to September 2018. Any patient presenting with acute idiopathic or chronic pancreatitis with a CT and/or MRI imaging negative for a pancreatic mass lesion that underwent an EUS during the study period was selected for inclusion. A retrospective review was performed to evaluate the outcomes of patients who had pancreatic cancer diagnosed from an EUS-FNA (fine needle aspiration) sample. Data were collected on patient demographics and clinical characteristics, inclusive of specific post-diagnosis treatment course. An "event rate" was calculated and is defined as the number of positive pancreatic cancer diagnoses on EUS-FNA from all patients presenting with acute idiopathic or chronic pancreatitis who underwent an EUS examination following a CT and/or MRI study negative for pancreatic mass lesion.

RESULTS

A total of 565 patients met inclusion criteria, with 30 cases of confirmed pancreatic cancer diagnosed with EUS-FNA from this group. The event rate for EUS diagnosis of pancreatic cancer was 5.3%. The majority of patients (52.0%) diagnosed with cancer were stages I-II.

CONCLUSIONS

Endoscopic ultrasound should be a routine part of the diagnostic algorithm when evaluating a patient with acute idiopathic or chronic pancreatitis of unclear etiology, particularly when cross-sectional imaging is negative for a mass lesion and clinical suspicion is high for neoplasia. Further prospective studies are needed to evaluate the role of EUS in this setting.

Imaging of Tropical Chronic Pancreatitis—A Unique Clinico-Radiological Entity

Tropical chronic pancreatitis (TCP) is a unique juvenile nonalcoholic form of chronic pancreatitis prevalent in tropical developing countries. TCP is characterized by the younger age of onset, rapid progression, higher prevalence of diabetes and pancreatic calculi, and greater propensity to develop pancreatic malignancy. Identifying the distinct imaging features is critical for the diagnosis of TCP. Awareness of this condition will not only enable the radiologist to recognize it early but also help in better management. In this article, we review the etiopathogenesis, distinct imaging features, and complications of TCP.

Chronic Pancreatitis or Pancreatic Tumor? A Problem-solving Approach

Certain inflammatory pancreatic abnormalities may mimic pancreatic ductal adenocarcinoma at imaging, which precludes accurate preoperative diagnosis and may lead to unnecessary surgery. Inflammatory conditions that may appear masslike include mass-forming chronic pancreatitis, focal autoimmune pancreatitis, and paraduodenal pancreatitis or "groove pancreatitis." In addition, obstructive chronic pancreatitis can mimic an obstructing ampullary mass or main duct intraductal papillary mucinous neoplasm. Secondary imaging features such as the duct-penetrating sign, biliary or main pancreatic duct skip strictures, a capsulelike rim, the pancreatic duct-to-parenchyma ratio, displaced calcifications in patients with chronic calcific pancreatitis, the "double duct" sign, and vessel encasement or displacement can help to suggest the possibility of an inflammatory mass or a neoplastic process. An awareness of the secondary signs that favor a diagnosis of malignant or inflammatory lesions in the pancreas can help the radiologist to perform the differential diagnosis and determine the degree of suspicion for malignancy. Repeat biopsy or surgical resection may be necessary to achieve an accurate diagnosis and prevent unnecessary surgery for inflammatory conditions. Online supplemental material and DICOM image stacks are available for this article. ^©RSNA, 2019.

Endoscopic ultrasound-guided sampling of solid pancreatic masses: the fine needle aspiration or fine needle biopsy dilemma. Is the best needle yet to come?

Fine needle aspiration (FNA) is currently the standard of care for sampling pancreatic solid masses by using endoscopic ultrasound (EUS). The accuracy of the technique is reported to be high, especially if coupled with the rapid on site evaluation (ROSE), and it has a high safety profile. However, FNA presents some limitations, such as the small amount of tissue that can be collected and the inability of obtaining a core tissue with intact histological architecture, which is relevant to perform immunohistochemical analysis, molecular profiling and, therefore, targeted therapies. Moreover, the presence of the ROSE by an expert cytopathologist is very important to maximize the diagnostic yield of FNA technique; however, it is not widely available, especially in small centers. Hence, the introduction of EUS fine needle biopsy (FNB) with a new generation of needles, which show a high safety profile too and a satisfying diagnostic accuracy even in the absence of ROSE, could be the key to overcome the limitations of FNA. However, FNB has not yet shown diagnostic superiority over FNA. Considering all the technical aspects of FNA and FNB, the different types of needle currently available, comparisons in term of diagnostic yield, and the different techniques of sampling, a tailored approach should be used in order to determine the needle that is most appropriate for the different specific scenarios.

Predictors of Malignancies in Patients with Inconclusive or Negative Results of Endoscopic Ultrasound-guided Fine-needle Aspiration for Solid Pancreatic Masses

Background/Aims

This study analyzed the diagnostic accuracy of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for pancreatic solid masses in patients with or without chronic pancreatitis as well as the clinical parameters relevant to a malignancy when EUS-FNA was negative or inconclusive.

Methods

A total of 97 patients, who underwent EUS-FNA for solid pancreatic masses over 2 years at a single institution, were evaluated. All patients underwent EUS-FNA for 3-5 passes with 22 or 25 G needles without an on-site cytopathologist. The final diagnosis was obtained by surgery or compatible clinical outcomes for a more than 12 month follow-up. The diagnostic yields in the patients with or without chronic pancreatitis were compared and the histories and laboratory data relevant to pancreatic ductal adenocarcinoma (PDAC) or pseudo-tumor were analyzed.

Results

The final diagnoses were adenocarcinoma in 88 patients (90.7%) and inflammatory pseudo-tumor in 9 (9.3%). The results of EUS-FNA were adenocarcinoma (74), suspicious (7), atypical (5), negative (10), and inadequate specimen (1). The diagnostic accuracies were 76.9% and 91.6% in patients with or without chronic pancreatitis, respectively. Among the 23 cases with non-diagnostic results of EUS-FNA, PDAC was finally diagnosed in 5 out of 7 suspicious, 3 out of 5 atypical, and 5 out of 10 negative cytology cases. The clinical parameters related to a pseudo-tumor were a history of alcohol consumption and pancreatitis, and normal alkaline phosphatase levels.

Conclusions

The diagnostic accuracy of pancreatic masses in the background of chronic pancreatitis was low. When EUS-FNA produced inconclusive results, the histories of alcohol consumption, pancreatitis, and serum levels of alkaline phosphatase are useful for making a final diagnosis.

10 Fr S-Type Plastic Pancreatic Stents in Chronic Pancreatitis Are Effective for the Treatment of Pancreatic Duct Strictures and Pancreatic Stones

AIM

Endoscopic pancreatic stenting for refractory pancreatic duct strictures associated with impacted pancreatic stones in chronic pancreatitis cases has yielded conflicting results. We retrospectively evaluated the efficacy of endoscopic treatment in chronic pancreatitis patients with pancreatic duct strictures.

METHODS

Pancreatic sphincterotomy, dilatation procedures, pancreatic brush cytology, and pancreatic juice cytology were routinely performed, and malignant diseases were excluded. After gradual dilatation, a 10 Fr plastic pancreatic stent was inserted. The stents were replaced every 3 months and removed after the strictures were dilated. Statistical analyses were performed to determine the risk of main pancreatic duct restenosis.

RESULTS

Endoscopic pancreatic stents were successfully placed in 41 of a total of 59 patients (69.5%). The median duration of pancreatic stenting was 276 days. Pain relief was obtained in 37 of 41 patients (90.2%). Seventeen patients (41.5%) had recurrence of main pancreatic duct stricture, and restenting was performed in 16 patients (average placement period 260 days). During the follow-up period, pancreatic cancer developed in three patients (5.1%). Multivariate analysis revealed that the presence of remnant stones after stenting treatment was significantly associated with a higher rate of main pancreatic duct restenosis (p = 0.03).

CONCLUSION

The use of 10 Fr S-type plastic pancreatic stents with routine exchange was effective for both short-term and long-term outcomes in chronic pancreatitis patients with benign pancreatic duct strictures and impacted pancreatic stones.

Influence of the Histopathological Features of the Lesion on the Diagnostic Yield of Fine-Needle Aspiration Cytology of Pancreatic Solid Lesions

OBJECTIVE

The rate of pancreatic lesions has increased in recent decades due to the widespread use of advanced imaging techniques. Nowadays, a significant proportion of cases are incidentally discovered in asymptomatic patients and cytology is an important tool for the diagnosis and multidisciplinary management of these cases.

STUDY DESIGN

In this study we retrospectively review the experience with pancreatic fine-needle aspiration cytology in the last 17 years at a single large tertiary hospital in Madrid, Spain.

RESULTS

Our results indicate that more than 60% of pancreatic malignant lesions are cytologically confirmed before surgery and 30% of the patients are asymptomatic. Despite this, we have noted that the total number of malignant lesions surgically resected in our hospital has basically remained unchanged over the years, because incidental diagnosis is not always synonymous with resectability and a substantial number of patients are already metastatic at the time of diagnosis. Our series also shows an increase in the number of neuroendocrine tumors, which now represent almost 20% of all cytological diagnoses at our hospital. The sensitivity in our series is 70% and the false negative rate remains 30%, despite sample quality control by experienced cytologists and standardized technical conditions. Fibrosis and necrosis are the 2 features of the primary tumor that significantly and negatively influence the accuracy of cytologic diagnosis.

CONCLUSION

We herein report our experience with cytologic diagnosis of pancreatic lesions in a single tertiary hospital. Our results confirm that cytology is a safe, reliable, and important tool for pancreatic lesion diagnosis and management.

Endoscopic ultrasound elastography for solid pancreatic lesions

Elastography is one of technologies assisting diagnosis of solid pancreatic lesions (SPL). This technology has been previously used for measuring the stiffness of various organs based on a principle of “harder the lesions, higher chance for malignancy”. Two elastography techniques; strain and shear wave elastography, are available. For endoscopic ultrasound (EUS), only the former is existing. To interpret results of EUS elastography for SPL, 3 methods are used: (1) pattern recognition; (2) strain ratio; and (3) strain histogram. Based on results of existing studies, these 3 techniques provide high sensitivity but low to moderate specificity and accuracy rate. This review will summarize all available information in order to update current situation of using elastography for an evaluation of SPLs to readers.

Total pancreatectomy for recurrent acute and chronic pancreatitis: a critical review of patient selection criteria

PURPOSE OF REVIEW

Critical review of the indications for total pancreatectomy and highlight limitations in current diagnostic criteria for chronic pancreatitis.

RECENT FINDINGS

The diagnosis of noncalcific chronic pancreatitis remains controversial because of an overreliance on nonspecific imaging and laboratories findings. Endoscopic ultrasound, s-magnetic resonance cholangiopancreatography, and/or endoscopic pancreatic function testing are often used to diagnose noncalcific chronic pancreatitis despite the fact that there is no gold standard for this condition. Abdominal pain is not specific for chronic pancreatitis and is more likely to be encountered in patients with functional gastrointestinal disorders based on the high incidence of these conditions. The duration of pain and opioid analgesic use results in central sensitization that adversely affects pain outcomes after total pancreatectomy. An alcoholic cause is associated with poorer pain outcomes after total pancreatectomy.

SUMMARY

The lack of a gold standard for noncalcific chronic pancreatitis limits the diagnostic accuracy of imaging and laboratory tests. The pain of chronic pancreatitis is nonspecific and is affected by duration, preoperative opioid use, and cause. These factors will need to be considered in the development of future selection criteria for this morbid surgery.

Real time endoscopic ultrasound elastography and strain ratio in the diagnosis of solid pancreatic lesions

AIM

To evaluate the accuracy of the elastography score combined to the strain ratio in the diagnosis of solid pancreatic lesions (SPL).

METHODS

A total of 172 patients with SPL identified by endoscopic ultrasound were enrolled in the study to evaluate the efficacy of elastography and strain ratio in differentiating malignant from benign lesions. The semi quantitative score of elastography was represented by the strain ratio method. Two areas were selected, area (A) representing the region of interest and area (B) representing the normal area. Area (B) was then divided by area (A). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated by comparing diagnoses made by elastography, strain ratio and final diagnoses.

RESULTS

SPL were shown to be benign in 49 patients and malignant in 123 patients. Elastography alone had a sensitivity of 99%, a specificity of 63%, and an accuracy of 88%, a PPV of 87% and an NPV of 96%. The best cut-off level of strain ratio to obtain the maximal area under the curve was 7.8 with a sensitivity of 92%, specificity of 77%, PPV of 91%, NPV of 80% and an accuracy of 88%. Another estimated cut off strain ratio level of 3.8 had a higher sensitivity of 99% and NPV of 96%, but with less specificity, PPV and accuracy 53%, 84% and 86%, respectively. Adding both elastography to strain ratio resulted in a sensitivity of 98%, specificity of 77%, PPV of 91%, NPV of 95% and accuracy of 92% for the diagnosis of SPL.

CONCLUSION

Combining elastography to strain ratio increases the accuracy of the differentiation of benign from malignant SPL.

Diagnostic value of targeted next-generation sequencing in patients with suspected pancreatic or periampullary cancer

Aims

Radiological imaging and morphological assessment of cytology material have limitations for preoperative classification of pancreatic or periampullary lesions, often resulting in surgical resection without definitive diagnosis. Our prospective study aims to define the diagnostic value of targeted next-generation sequencing (NGS) of DNA from cytology material.

Methods

Patients with a suspect pancreatic or periampullary lesion underwent standard diagnostic evaluation including preoperative morphological cytology assessment. Treatment options for suspect lesions were surgical exploration with possible resection, follow-up or palliation. The cytology samples were analysed with NGS, in which 50 genes were sequenced for the presence of pathogenic variants. The NGS results were integrated with the clinical information during multidisciplinary team meetings, and changes in the treatment plan were scored. Diagnostic accuracy of NGS analysis (malignancy vs benign disease) was calculated.

Results

NGS results of the cytology samples were confirmed in the resection specimens of the first 10 included patients. The integration of the NGS results led to a change in treatment plan in 7 out of 70 patients (from exploration to follow-up, n=4; from follow-up to exploration and resection, n=2; from palliation to resection, n=1). In four patients, the NGS results were contradictory, but did not affect the treatment plan. In the remaining 59 patients, NGS analysis supported the initial treatment plan. The diagnostic accuracy of NGS analysis was 94% (sensitivity=93%; specificity=100%).

Conclusions

NGS can change the treatment plan in a significant portion of patients with suspect pancreatic or periampullary lesions. Application of NGS can optimise treatment selection and diminish unnecessary surgeries.

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 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.

Endoscopic Ultrasound: Reaching Where Others Can't

Endoscopic ultrasound (EUS) has been increasingly used for the diagnosis and staging of pancreatic cancer. It has recently become the modality of choice in assessing pancreatic lesions overcoming other traditional modalities. Typically lesions located at the tail of the pancreas are best accessed through the stomach. We present a patient with pancreatic tail mass occurring in the setting of a large hiatal hernia, intrathoracic stomach, and severe lumbar levoscoliosis. Due to altered anatomy and extensive vascular connections of the mass, any surgical or radiological intervention was considered high risk for the patient. EUS was the only modality capable of providing a pancreatic mass tissue sample in this patient with challenging thoraco-abdominal anatomy. Moreover, pancreatic tail lesions are traditionally best accessed through the gastric fundus; however, in view of the patient's altered anatomy, EUS-fine needle aspiration (FNA) had to be performed through the duodenum. This case raises the importance of EUS when surgical and radiological interventions are restricted.

Novel quantitative analysis of the S100P protein combined with endoscopic ultrasound-guided fine needle aspiration cytology in the diagnosis of pancreatic adenocarcinoma

Specimens obtained with endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) are often tiny and fragmented leading to an inconclusive and doubtful diagnosis. To overcome the limitations of EUS-FNA in the cytological diagnosis of pancreatic adenocarcinoma (PCA), we evaluated whether quantification of the S100P protein combined with EUS-FNA reliably discriminated between PCA and benign pancreatic lesions (BPL). A high sensitivity sandwich ELISA for S100P protein was developed to aid in the detection of PCA in small samples obtained using EUS-FNA. After experimental verification of the sandwich ELISA with cell lines and mouse xenograft tumors, 27 consecutive patients with suspicious PCA who underwent EUS-FNA were enrolled in the present study examining the combination of S100P protein assessment and EUS-FNA cytology. The concentration of the S100P protein in EUS-FNA samples from the PCA group was significantly higher than that in the BPL group (P=0.04). Using receiver operating characteristic curve analysis, we determined the S100P protein cut-off value for PCA diagnosis to be 99.8 ng/ml. The S100P protein levels combined with EUS-FNA cytology to detect PCA showed the following diagnostic values: sensitivity, 94.4% [95% confidence interval (CI), 75.7-99.1%]; specificity, 88.9% (95% CI, 51.8-99.7%); positive predictive value, 94.4% (95% CI, 72.7-99.9%); negative predictive value, 88.9% (95% CI, 51.8-99.7%); accuracy, 92.6% (95% CI, 75.7‑99.1%); and area under the curve, 0.92 (95% CI, 0.79-1.00). We established a novel quantitative analysis for the S100P protein in EUS-FNA samples which, when combined with EUS-FNA cytology, could provide promising results for the reliable diagnosis of PCA.

Toward optical guidance during endoscopic ultrasound-guided fine needle aspirations of pancreatic masses using single fiber reflectance spectroscopy: a feasibility study

Endoscopic ultrasound-guided fine needle aspirations (EUS-FNA) of pancreatic masses suffer from sample errors and low-negative predictive values. Fiber-optic spectroscopy in the visible to near-infrared wavelength spectrum can noninvasively extract physiological parameters from tissue and has the potential to guide the sampling process and reduce sample errors. We assessed the feasibility of single fiber (SF) reflectance spectroscopy measurements during EUS-FNA of pancreatic masses and its ability to distinguish benign from malignant pancreatic tissue. A single optical fiber was placed inside a 19-gauge biopsy needle during EUS-FNA and at least three reflectance measurements were taken prior to FNA. Spectroscopy measurements did not cause any related adverse events and prolonged procedure time with ? 5 ?? min . An accurate correlation between spectroscopy measurements and cytology could be made in nine patients (three benign and six malignant). The oxygen saturation and bilirubin concentration were significantly higher in benign tissue compared with malignant tissue (55% versus 21%, p = 0.038 ; 166 ?? ? mol / L versus 17 ?? ? mol / L , p = 0.039 , respectively). To conclude, incorporation of SF spectroscopy during EUS-FNA was feasible, safe, and relatively quick to perform. The optical properties of benign and malignant pancreatic tissue are different, implying that SF spectroscopy can potentially guide the FNA sampling.