The No Endosonographic Detection of Tumor (NEST) Study: a case series of pancreatic cancers missed on endoscopic ultrasonography

Endoscopic Ultrasound in Cancer Staging

The authors review the role of endoscopic ultrasound (EUS) in the staging of cancers throughout the gastrointestinal tract. EUS offers an advantage over cross-sectional imaging in locoregional tumor staging but is less sensitive in identifying distant metastasis. The addition of FNA increases diagnostic accuracy and provides a tissue diagnosis. EUS combined with cross-sectional imaging is important in accurately staging GI tumors and thereby reducing unnecessary procedures and health care costs.

Diagnostic Endoscopic Ultrasound in Pancreatology: Focus on Normal Variants and Pancreatic Masses

Background

Endoscopic ultrasound (EUS) is a main tool in gastroenterology for both diagnosis and exclusion of pancreatic pathology. It allows minimally invasive assessment of various diseases or anatomic variations affecting the pancreas also with the help of new Doppler technologies, elastography, contrast-enhanced imaging including post hoc image processing with quantification analyses, three-dimensional reconstruction, and artificial intelligence. EUS also allows interventional direct access to the pancreatic parenchyma and the retroperitoneal space, to the pancreatic duct, pancreatic masses, cysts, and vascular structures.

Summary

This review aimed to summarize new developments of EUS in the field of pancreatology. We highlight the role of EUS in evaluating pancreatic pathology by describing normal anatomic variants like pancreas divisum, pancreatic lipomatosis, pancreatic fibrosis in the elderly and characterizing pancreatic masses, both in the context of chronic pancreatitis and within healthy pancreatic parenchyma. EUS is considered the optimal imaging modality for pancreatic masses of uncertain dignity and allows both cytological diagnosis and histology, which is essential not only for neoplastic conditions but also for tailoring therapy for benign inflammatory conditions.

Key Messages

EUS plays an indispensable role in pancreatology and the development of new diagnostic and interventional approaches to the retroperitoneal space and the pancreas exponentially increased over the last years. The development of computer-aided diagnosis and artificial intelligence algorithms hold the potential to overcome the obstacles associated with interobserver variability and will most likely support decision-making in the management of pancreatic disease.

Surgical pancreatic biopsies for cases with locally advanced pancreatic cancer with inconclusive histology after interventional biopsy

Background

Histopathological confirmation of malignancy is mandatory in patients with unresectable pancreatic cancer before initiation of palliative chemotherapy. When interventional biopsy proves unsuccessful, laparoscopic or open surgical biopsies become necessary.

Methods

66 consecutive surgical biopsies of the pancreas performed at a single institution between 01/2010 and 04/2020 were analyzed retrospectively. We analyzed sensitivity of histopathological confirmation of malignancy as well as complication rates of laparoscopic and open surgical biopsies in patients with suspected advanced pancreatic cancer after unsuccessful interventional biopsies.

Results

8 complications were observed in 46 patients requiring only a pancreatic biopsy (17.4 %) while in 13 of 20 patients complications were observed when additional procedures were necessary (65 %). Major complications CD ≥ III were observed in the "biopsy +/- port" group in 4 of 46 patients and in the "biopsy + additional procedure" cohort in 9 of 20 patients (8.7 vs. 45 %, p < 0.001). Despite the trend to reduced perioperative complications in laparoscopic biopsies, the reduction did not reach statistical significance when compared to open resections (11.1 vs. 26.3 %, p = 0.18). Surgical pancreatic biopsies reached a sensitivity regarding the correct definite histopathological result of 90.32 %, specificity was 100 %.

Conclusion

Both laparoscopic and open biopsies can be performed at acceptable complication rates CD ≥ III of 8.7 % and present a valuable option after failure of image-guided techniques for biopsy. Additional operative measures in locally advanced pancreatic carcinoma ought to be critically reflected due to a substantially higher complication rate CD ≥ III of 45 %.

Key message

Laparoscopic and open surgical biopsies in patients with unresectable pancreatic cancer demonstrate a high diagnostic sensitivity at acceptable complication rates. This finding is important because it provides further support for surgical biopsies to avoid delay before initiation of palliative therapy.

Surgical Diagnoses of Pancreatic Adenocarcinoma Not Found on Previous Endoscopic Ultrasound: A Case Series and Review of the Literature

INTRODUCTION

Pancreatic cancer is a leading cause of death in North America and Western Europe with rising rates in the developing world. Endoscopic ultrasound (EUS) with FNA (fine needle aspiration) is a critical component in the evaluation and diagnosis of pancreatic lesions with a high sensitivity and specificity. In this paper, we report patients at our center who eventually developed pancreatic cancer despite an early negative EUS, and identifying factors that may result in a missed diagnosis.

METHODS

The University of Louisville database was queried for patients who had a Whipple procedure for presumed benign disease and had a pre-operative EUS between 2008 and 2018. Patients who had pancreatic adenocarcinoma on final pathology were identified. Demographic, clinical, EUS, operative, and pathologic details were reviewed for each case in efforts to identify factors associated with failure to diagnose a pancreatic malignancy on EUS.

RESULTS

Five patients who had pancreatic adenocarcinoma on final pathology were reviewed in detail and their cases are presented in the paper. Four of the patients had dilation of the common bile duct, three had chronic pancreatitis. Two of them had previous surgery on the pancreas or bile ducts.

CONCLUSIONS

All of the patients presented in the paper had variables that made their EUS evaluation challenging. A high index of suspicion must be maintained in patients that do not improve after appropriate treatment of their strictures or pancreatic lesions. In the future, new techniques, such as fine needle biopsy and biomarker assays, may improve diagnosis accuracy.

Rate of pancreatic cancer following a negative endoscopic ultrasound and associated factors

BACKGROUND : Data are limited regarding pancreatic cancer diagnosed following a pancreaticobiliary endoscopic ultrasound (EUS) that does not diagnose pancreatic cancer. We have studied the frequency of, and factors associated with, post-EUS pancreatic cancer (PEPC) and 1-year mortality. METHODS : Between 2010 and 2017, patients with pancreatic cancer and a preceding pancreaticobiliary EUS were identified in a national cohort using Hospital Episode Statistics. Patients with a pancreaticobiliary EUS 6-18 months before a later pancreatic cancer diagnosis were the PEPC cases; controls were those with pancreatic cancer diagnosed within 6 months of pancreaticobiliary EUS. Multivariable logistic regression models examined the factors associated with PEPC and a Cox regression model examined factors associated with 1-year cumulative mortality. RESULTS : 9363 pancreatic cancer patients were studied; 93.5 % identified as controls (men 53.2 %; median age 68 [interquartile range (IQR) 61-75]); 6.5 % as PEPC cases (men 58.2 %; median age 69 [IQR 61-77]). PEPC was associated with older age (≥ 75 years compared with < 65 years, odds ratio [OR] 1.42, 95 %CI 1.15-1.76), increasing co-morbidity (Charlson co-morbidity score > 5, OR 1.90, 95 %CI 1.49-2.43), chronic pancreatitis (OR 3.13, 95 %CI 2.50-3.92), and diabetes mellitus (OR 1.58, 95 %CI 1.31-1.90). Metal biliary stents (OR 0.57, 95 %CI 0.38-0.86) and EUS-FNA (OR 0.49, 95 %CI 0.41-0.58) were inversely associated with PEPC. PEPC was associated with a higher cumulative mortality at 1 year (hazard ratio 1.12, 95 %CI 1.02-1.24), with only 14 % of PEPC patients (95 %CI 12 %-17 %) having a surgical resection, compared with 21 % (95 %CI 20 %-22 %) of controls. CONCLUSIONS : PEPC occurred in 6.5 % of patients and was associated with chronic pancreatitis, older age, more co-morbidities, and specifically diabetes mellitus. PEPC was associated with a worse prognosis and lower surgical resection rates.

Prognosis and Clinical Characteristics of Patients with Pancreatic Ductal Adenocarcinoma Diagnosed by Endoscopic Ultrasonography but Indeterminate on Computed Tomography

Background/Aims

Endoscopic ultrasonography (EUS) provides high-resolution images and is superior to computed tomography (CT) scan in diagnosing small pancreatic ductal adenocarcinoma (PDAC). As a result, the use of EUS for early detection of PDAC has attracted attention. This study aimed to identify the clinical and radiological characteristics of patients with PDAC diagnosed by EUS but not found on CT scan.

Methods

The medical records of patients diagnosed with PDAC at 12 tertiary referral centers in Korea from January 2003 to April 2019 were reviewed. This study included patients with pancreatic masses not clearly observed on CT scan but identified on EUS. The clinical characteristics and radiological features of the patients were analyzed, and survival analysis was performed.

Results

A total of 83 patients were enrolled. The most common abnormal CT findings other than a definite mass was pancreatic duct dilatation, which was identified in 61 patients (73.5%). All but four patients underwent surgery. The final pathologic stages were as follows: IA (n=31, 39.2%), IB (n=8, 10.1%), IIA (n=20, 25.3%), IIB (n=17, 21.5%), III (n=2, 2.5%), and IV (n=1, 1.4%). The 5-year survival rate of these patients was 50.6% (95% confidence interval, 38.8% to 66.7%). Elevated liver function testing and R1 resection emerged as significant predictors of mortality in the multivariable Cox regression analysis.

Conclusions

This multicenter study demonstrated favorable long-term prognosis in patients with PDAC diagnosed by EUS but indeterminate on CT scan. EUS should be considered for patients with suspected PDAC but indeterminate on CT scan.

Endoscopic ultrasound with combined fine needle aspiration plus biopsy improves diagnostic yield in solid pancreatic masses

GOALS

Our aim was to compare the diagnostic yield of endoscopic ultrasound guided fine needle aspiration (EUS-FNA) versus combined fine needle aspiration and fine needle biopsy (EUS-FNA + FNB) in the evaluation of solid pancreatic masses (SPMs).

BACKGROUND

EUS-FNA and EUS-FNB are established methods to diagnose SPMs. No studies have evaluated the efficacy of combination of both (EUS-FNA + FNB). Our senior author (MRS) hypothesized that combining the two techniques by using a single FNB needle improves diagnostic yield and started combination technique in October 2016.

STUDY

Patients who underwent EUS for SPMs by MRS during January 2014-September 2019 were included. They were divided into the EUS-FNA group and EUS-FNA + FNB group. EUS-FNA was performed using a 22 or 25 gauge Expect Slimline needle (Boston Scientific, Marlborough, MA) and EUS-FNA + FNB was performed using a single 22 or 25 gauge Shark-core needle (Medtronics, Minneapolis, MN, USA). Our primary outcome was to compare the diagnostic yield in the two groups.

RESULTS

Among 105 patients included, 58 were in the EUS-FNA group and 47 were in the EUS-FNA + FNB group. EUS-FNA + FNB group had significantly higher diagnostic yield and required fewer needle passes compared to EUS-FNA group, 95.7% vs. 77.6%, p = .01: and 4 vs. 5, p = .002; respectively. Procedural duration was similar in both groups but the combined technique required less number of needles per procedure. There was no difference in adverse events in the two groups.

CONCLUSION

Our study showed that combined EUS-FNA + FNB had higher diagnostic yield compared to EUS-FNA in SPMs along with less number of needle passes and needles required. Further prospective studies are needed to validate these findings and cost-effectiveness of this strategy.

Advanced Imaging of the Biliary System and Pancreas

Despite advances in noninvasive techniques for imaging the pancreaticobiliary system, several disease processes including indeterminate biliary strictures as well as neuroendocrine tumors, inflammatory pseudotumors, and complex cysts of the pancreas remain difficult to characterize. New endoscopic imaging technologies have emerged to address these challenges. Cholangioscopy and intraductal ultrasound (IDUS) are powerful tools to characterize subtle biliary concretions and strictures. Confocal Laser Endomicroscopy (CLE) and Optical Coherence Tomography (OCT) are emerging approaches for the most difficult biliary lesions. Contrast harmonic endoscopic ultrasound (CH-EUS), elastography, and 3D-EUS are improving the approach to subtle pancreatic lesions, particularly in the context of indeterminate tissue sampling. Pancreatoscopy, pancreatic IDUS, and intracystic CLE hold promise to further improve the assessment of pancreatic cysts. We aim to comprehensively review the emerging clinical evidence for these innovative endoscopic imaging techniques.

Application of artificial intelligence for diagnosis of pancreatic ductal adenocarcinoma by EUS: A systematic review and meta-analysis

EUS-guided tissue acquisition carries certain risks from unnecessary needle puncture in the low-likelihood lesions. Artificial intelligence (AI) system may enable us to resolve these limitations. We aimed to assess the performance of AI-assisted diagnosis of pancreatic ductal adenocarcinoma (PDAC) by off-line evaluating the EUS images from different modes. The databases PubMed, EMBASE, SCOPUS, ISI, IEEE, and Association for Computing Machinery were systematically searched for relevant studies. The pooled sensitivity, specificity, diagnostic odds ratio (DOR), and summary receiver operating characteristic curve were estimated using R software. Of 369 publications, 8 studies with a total of 870 PDAC patients were included. The pooled sensitivity and specificity of AI-assisted EUS were 0.91 (95% confidence interval [CI], 0.87-0.93) and 0.90 (95% CI, 0.79-0.96), respectively, with DOR of 81.6 (95% CI, 32.2-207.3), for diagnosis of PDAC. The area under the curve was 0.923. AI-assisted B-mode EUS had pooled sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 0.91, 0.90, 0.94, and 0.84, respectively; while AI-assisted contrast-enhanced EUS and AI-assisted EUS elastography had sensitivity, specificity, PPV, and NPV of 0.95, 0.95, 0.97, and 0.90; and 0.88, 0.83, 0.96 and 0.57, respectively. AI-assisted EUS has a high accuracy rate and may potentially enhance the performance of EUS by aiding the endosonographers to distinguish PDAC from other solid lesions. Validation of these findings in other independent cohorts and improvement of AI function as a real-time diagnosis to guide for tissue acquisition are warranted.

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

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

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

BACKGROUND AND AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

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

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

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.

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.

"Invisible" pancreatic masses identified by EUS by the "ductal cutoff sign"

Making a tissue diagnosis of pancreatic adenocarcinoma is best accomplished by EUS and fine-needle aspiration (FNA) of the lesion. Typically, a dark, or “hypoechoic” mass will be seen, which presents an obvious target for FNA. For small lesions, computerized tomography (CT) may be negative, but the lesion is still almost always seen on EUS imaging. Rarely, a pancreatic mass will appear isoechoic on EUS imaging. We report three “invisible” pancreatic masses identified only by a cutoff in the pancreatic duct (PD) and/or common bile duct (CBD). No mass, isoechoic or otherwise, was seen. EUS-FNA was performed in the area of ductal narrowing, with a positive identification of adenocarcinoma in these cases.

Endoscopic Ultrasound-Guided Tissue Acquisition Using Fork-Tip Needle Improves Histological Yield, Reduces Needle Passes, Without On-Site Cytopathological Evaluation

Background and Aim: Endoscopic ultrasound (EUS)-guided fine needle biopsy (FNB) and fine needle aspiration (FNA) are established methods in tissue acquisition. A new fork-tip FNB needle has been used to obtain core tissue samples. We compared the performance of the FNB using fork-tip needles with that of the FNA using conventional needles in patients who had solid neoplastic lesions within and around the upper gastrointestinal (GI) tract.

Methods: In this retrospective single-center study, patients who underwent EUS examinations for solid neoplastic lesions between October 2013 and February 2017 were included. The procedures were performed in the absence of an on-site cytologist. The main objectives were to compare the diagnostic yield and average number of passes of FNB using fork-tip needles versus those of FNA using conventional needles.

Results: EUS/FNA and EUS/FNB were performed on 181 solid neoplastic lesions primarily in the pancreas and GI tract walls. There was no significant difference in patient's age, gender, tumor location, or tumor size. The mean number of needle passes was significantly lower in the fork-tip needle group than in the conventional needle group (3.8 vs. 5.9; p < 0.0001). There was a trend toward higher sensitivity (89.9% vs. 81%) using the fork-tip needles than when using the conventional needles (p = 0.119). No significant difference in rates of adverse events between two groups was found.

Conclusions: Our study demonstrates that, compared with FNA using conventional needles, FNB using fork-tip needles required significantly fewer needle passes while achieving a relatively higher diagnostic yield due to its superior capacity in tissue acquisition from solid neoplastic lesions in and around GI tract walls without on-site cytological assessment.

Advanced EUS Guided Tissue Acquisition Methods for Pancreatic Cancer

Pancreas cancer is a lethal cancer as the majority patients are diagnosed at an advanced incurable stage. Despite improvements in diagnostic modalities and management strategies, including surgery and chemotherapies, the outcome of pancreas cancer remains poor. Endoscopic ultrasound (EUS) is an important imaging tool for pancreas cancer. For decades, resected pancreas cancer and other cancer specimens have been used to identify tissue biomarkers or genomics for precision therapy; however, only 20% of patients undergo surgery, and thus, this framework is not useful for unresectable pancreas cancer. With advancements in needle technologies, tumor specimens can be obtained at the time of tissue diagnosis. Tumor tissue can be used for development of personalized cancer treatment, such as performing whole exome sequencing and global genomic profiling of pancreas cancer, development of tissue biomarkers, and targeted mutational assays for precise chemotherapy treatment. In this review, we discuss the recent advances in tissue acquisition of pancreas cancer.

Gastroenterology and pancreatic adenocarcinoma: what the radiologist needs to know

In this article, we review the information that radiologists need to know regarding the endoscopic approach to the diagnosis and management of pancreatic cancer. This includes a review of the indications, techniques, and complications of endoscopic ultrasound. We also review information regarding endoscopic retrograde cholangiopancreatography, including the various biliary drainage techniques and the use of endoscopic palliation for patients with pancreatic cancer.

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.

A Multidisciplinary Approach to Pancreas Cancer in 2016: A Review

In this article, we review our multidisciplinary approach for patients with pancreatic cancer. Specifically, we review the epidemiology, diagnosis and staging, biliary drainage techniques, selection of patients for surgery, chemotherapy, radiation therapy, and discuss other palliative interventions. The areas of active research investigation and where our knowledge is limited are emphasized.

Endoscopic Ultrasound Elastography: Current Clinical Use in Pancreas

Elastography is a newer technique for the assessment of tissue elasticity using ultrasound. Cancerous tissue is known to be stiffer (hence, less elastic) than corresponding healthy tissue, and as a result, could be identified in an elasticity-based imaging. Ultrasound elastography has been used in the breast, thyroid, and cervix to differentiate malignant from benign neoplasms and to guide or avoid unnecessary biopsies. In the liver, elastography has enabled a noninvasive and reliable estimate of fibrosis. Endoscopic ultrasound has become a robust diagnostic and therapeutic tool for the management of pancreatic diseases. The addition of elastography to endoscopic ultrasound enabled further characterization of pancreas lesions, and several European and Asian studies have reported encouraging results. The current clinical role of endoscopic ultrasound elastography in the management of pancreas disorders and related literature are reviewed.

Endoscopic ultrasound of pancreatic lesions

Endoscopic ultrasound (EUS) is a well-established tool for the evaluation of pancreatic lesions. Due to the closer proximity of EUS to the pancreas, EUS offers a high sensitivity for detection of small pancreatic mass and is the preferred modality for obtaining tissue for diagnosis of pancreatic mass. Contrast-enhanced EUS and/or elastography provide additional information to the fundamental B-mode ultrasound images, leading to more accurate diagnosis. The aim of this video-article is to show the different steps in performing EUS on pancreatic lesions and to provide some tips and tricks to improve and facilitate the execution of EUS on pancreatic lesions.

A randomized controlled cross-over trial and cost analysis comparing endoscopic ultrasound fine needle aspiration and fine needle biopsy

BACKGROUND AND STUDY AIMS

Techniques to optimize endoscopic ultrasound-guided tissue acquisition (EUS-TA) in a variety of lesion types have not yet been established. The primary aim of this study was to compare the diagnostic yield (DY) of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) to endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) for pancreatic and non-pancreatic masses.

PATIENTS AND METHODS

Consecutive patients referred for EUS-TA underwent randomization to EUS-FNA or EUS-FNB at four tertiary-care medical centers. A maximum of three passes were allowed for the initial method of EUS-TA and patients were crossed over to the other arm based on on-site specimen adequacy.

RESULTS

A total of 140 patients were enrolled. The overall DY was significantly higher with specimens obtained by EUS-FNB compared to EUS-FNA (90.0 % vs. 67.1 %, P = 0.002). While there was no difference in the DY between the two groups for pancreatic masses (FNB: 91.7 % vs. FNA: 78.4 %, P = 0.19), the DY of EUS-FNB was higher than the EUS-FNA for non-pancreatic lesions (88.2 % vs. 54.5 %, P = 0.006). Specimen adequacy was higher for EUS-FNB compared to EUS-FNA for all lesions (P = 0.006). There was a significant rescue effect of crossover from failed FNA to FNB in 27 out of 28 cases (96.5 %, P = 0.0003). Decision analysis showed that the strategy of EUS-FNB was cost saving compared to EUS-FNA over a wide range of cost and outcome probabilities.

CONCLUSIONS

RESULTS of this RCT and decision analysis demonstrate superior DY and specimen adequacy for solid mass lesions sampled by EUS-FNB.

Endoscopic Ultrasound-Guided Fine-Needle Aspiration of Pancreatic Lesions: A Systematic Review of Technical and Procedural Variables

Endoscopic ultrasound (EUS)-guided tissue acquisition has emerged over the last decade as an invaluable diagnostic tool in approaching the different pancreatic lesions. Given the safety and minimal invasiveness of this approach combined with the high diagnostic yield, it became the standard of care when dealing with different pancreatic pathologies. However, some variables regarding this procedure remain not fully understood. These can influence the diagnostic yield of the procedure and include the presence of the on-site cytopathologist, the type and size of the needle used as well as obtaining aspiration versus core biopsy, the number of passes and the sampling technique, and the role of suction and stylet use among others. We performed a comprehensive literature search using PubMed, Google Scholar, and Embase for studies that assessed these variables. Eligible studies were analyzed using several parameters such as technique and procedure, with the aim of reviewing results from an evidence-based standpoint.

Review of current and evolving clinical indications for endoscopic ultrasound

For the first several years after its development, endoscopic ultrasound (EUS) was primarily limited to identification of pancreatic malignancies. Since this time, the field of EUS has advanced at a tremendous speed in terms of additional clinical diagnostic and therapeutic uses. The combination of ultrasound with endoscopy provides a unique interventional modality that is a minimally invasive alternative to various surgical interventions. Given the expanding recommended indications for EUS, this article will serve to review the most common uses with supporting evidence, while also exploring innovative endeavors that may soon become common clinical practice.

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.

Multiple pancreatic metastases from malignant melanoma: Conclusive diagnosis with endoscopic ultrasound-guided fine needle aspiration

Pancreatic metastases are rare, ranging from 2% to 5% of pancreatic malignancies. Differentiating a primary pancreatic malignancy from a metastasis can be difficult due to similarities on imaging findings, but is crucial to ensure proper treatment. Although transabdominal ultrasound, computed tomography, and magnetic resonance imaging provide useful images, endoscopic ultrasound (EUS) with fine needle aspiration (FNA) is often needed to provide a cytologic diagnosis. Here, we present a unique case of malignant melanoma with pancreatic metastases. It is important for clinicians to recognize the possibility of melanoma metastasizing to the pancreas and the role of EUS with FNA in providing cytological confirmation.

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.

Role of endoscopic ultrasound in the diagnosis of pancreatic cancer

Endoscopic ultrasonography (EUS) with or without fine needle aspiration has become the main technique for evaluating pancreatobiliary disorders and has proved to have a higher diagnostic yield than positron emission tomography, computed tomography (CT) and transabdominal ultrasound for recognising early pancreatic tumors. As a diagnostic modality for pancreatic cancer, EUS has proved rates higher than 90%, especially for lesions less than 2-3 cm in size in which it reaches a sensitivity rate of 99% vs 55% for CT. Besides, EUS has a very high negative predictive value and thus EUS can reliably exclude pancreatic cancer. The complication rate of EUS is as low as 1.1%-3.0%. New technical developments such as elastography and the use of contrast agents have recently been applied to EUS, improving its diagnostic capability. EUS has been found to be superior to the recent multidetector CT for T staging with less risk of overstaying in comparison to both CT and magnetic resonance imaging, so that patients are not being ruled out of a potentially beneficial resection. The accuracy for N staging with EUS is 64%-82%. In unresectable cancers, EUS also plays a therapeutic role by means of treating oncological pain through celiac plexus block, biliary drainage in obstructive jaundice in patients where endoscopic retrograde cholangiopancreatography is not affordable and aiding radiotherapy and chemotherapy.

Endoscopic ultrasonography for surveillance of individuals at high risk for pancreatic cancer

Pancreatic cancer is a highly lethal disease with a genetic susceptibility and familial aggregation found in 3%-16% of patients. Early diagnosis remains the only hope for curative treatment and improvement of prognosis. This can be reached by the implementation of an intensive screening program, actually recommended for individuals at high-risk for pancreatic cancer development. The aim of this strategy is to identify pre-malignant precursors or asymptomatic pancreatic cancer lesions, curable by surgery. Endoscopic ultrasound (EUS) with or without fine needle aspiration (FNA) seems to be the most promising technique for early detection of pancreatic cancer. It has been described as a highly sensitive and accurate tool, especially for small and cystic lesions. Pancreatic intraepithelial neoplasia, a precursor lesion which is highly represented in high-risk individuals, seems to have characteristics chronic pancreatitis-like changes well detected by EUS. Many screening protocols have demonstrated high diagnostic yields for pancreatic pre-malignant lesions, allowing prophylactic pancreatectomies. However, it shows a high interobserver variety even among experienced endosonographers and a low sensitivity in case of chronic pancreatitis. Some new techniques such as contrast-enhanced harmonic EUS, computer-aided diagnostic techniques, confocal laser endomicroscopy miniprobe and the detection of DNA abnormalities or protein markers by FNA, promise improvement of the diagnostic yield of EUS. As the resolution of imaging improves and as our knowledge of precursor lesions grows, we believe that EUS could become the most suitable method to detect curable pancreatic neoplasms in correctly identified asymptomatic at-risk patients.

Applications of endoscopic ultrasound in pancreatic cancer

Since the introduction of endoscopic ultrasound guided fine-needle aspiration (EUS-FNA), EUS has assumed a growing role in the diagnosis and management of pancreatic ductal adenocarcinoma (PDAC). The objective of this review is to discuss the various applications of EUS and EUS-FNA in PDAC. Initially, its use for detection, diagnosis and staging will be described. EUS and EUS-FNA are highly accurate modalities for detection and diagnosis of PDAC, this high accuracy, however, is decreased in specific situations particularly in the presence of chronic pancreatitis. Novel techniques such as contrast-enhanced EUS, elastography and analysis of DNA markers such as k-ras mutation analysis in FNA samples are in progress and might improve the accuracy of EUS in the detection of PDAC in this setting and will be addressed. EUS and EUS-FNA have recently evolved from a diagnostic to a therapeutic technique in the management of PDAC. Significant developments in therapeutic EUS have occurred including advances in celiac plexus interventions with direct injection of ganglia and improved pain control, EUS-guided fiducial and brachytherapy seed placement, fine-needle injection of intra-tumoral agents and advances in EUS-guided biliary drainage. The future role of EUS and EUS in management of PDAC is still emerging.

Clinical evaluation, imaging studies, indications for cytologic study and preprocedural requirements for duct brushing studies and pancreatic fine-needle aspiration: The Papanicolaou Society of Cytopathology Guidelines

The Papanicolaou Society of Cytopathology has developed a set of guidelines for pancreaticobiliary cytology including indications for endoscopic ultrasound (EUS) and fine-needle aspiration (FNA) biopsy, techniques for EUS-FNA, terminology and nomenclature to be used for pancreaticobiliary disease, ancillary testing and postbiopsy management. All documents are based on expertise of the authors, literature review, discussions of the draft document at national and international meetings and synthesis of online comments of the draft document. This document selectively presents the results of these discussions. This document summarizes recommendations for the clinical and imaging work-up of pancreatic and biliary tract lesions along with indications for cytologic study of these lesions. Prebrushing and FNA requirements are also discussed.

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.

Clinical evaluation, imaging studies, indications for cytologic study, and preprocedural requirements for duct brushing studies and pancreatic FNA: the Papanicolaou Society of Cytopathology recommendations for pancreatic and biliary cytology

The Papanicolaou Society of Cytopathology has developed a set of guidelines for pancreaticobiliary cytology including indications for endoscopic ultrasound (EUS) and fine-needle aspiration (FNA) biopsy, techniques for EUS-FNA, terminology and nomenclature to be used for pancreaticobiliary disease, ancillary testing, and post-biopsy management. All documents are based on expertise of the authors, literature review, discussions of the draft document at national and international meetings, and synthesis of online comments of the draft document. This document selectively presents the results of these discussions. This document summarizes recommendations for the clinical and imaging work-up of pancreatic and biliary tract lesions along with indications for cytologic study of these lesions. Prebrushing and FNA requirements are also discussed.

Contrast-enhanced endoscopic ultrasound

Compared to other imaging modalities, endoscopic ultrasound (EUS) has limitations in terms of image enhancement. However, with the availability of contrast agents in ultrasonography, EUS has evolved. Contrast-enhanced Doppler EUS (CD-EUS) enhances Doppler signals from vessels and is useful for characterizing lesions detected by EUS. Moreover, contrast-enhanced harmonic EUS (CH-EUS) with second-generation ultrasound contrast agents and a broad band transducer allows microvessels and parenchymal perfusion to be visualized. Vascularity can also be quantitatively analyzed during CH-EUS by generating a time-intensity curve. CE-EUS is useful for characterizing pancreatic lesions and can detect pancreatic adenocarcinomas with a sensitivity of 94%and a specificity of 89% as a result of the hypo-enhancement of these lesions. Indeed, CH-EUS is superior to multiple detector-computed tomography in terms of the differential diagnosis of small lesions that are ≤2 cm. CH-EUS complements EUS-guided fine-needle aspiration (EUS-FNA) as it identifies the EUS-FNA target and lesions with false-negative EUS-FNA findings. CH-EUS is also used to estimate the malignant potential of gastrointestinal stromal tumors and helps to differentiate between malignant and benign lymphadenopathy.

Differential Diagnosis of Focal Non-Cystic Pancreatic Lesions With and Without Proximal Dilation of Pancreatic Duct Noted on CT Scan

OBJECTIVES:

Pancreatic duct (PD) dilation proximal to a solid focal pancreatic lesion on computed tomography (CT) scan is considered highly suggestive of pancreatic adenocarcinoma. There is, however, no published data on the differential diagnosis of focal non-cystic pancreatic lesions with and without PD dilation. We assessed the diagnostic utility of this radiologic finding.

METHODS:

This is a retrospective analysis of a prospectively maintained database of university-based clinical practice. A total of 445 non-jaundiced patients who underwent endoscopic ultrasound (EUS) (2002–2010) for evaluation of solid pancreatic lesions noted on CT scan were included. Final diagnosis was based on surgical pathology or definitive cytology with supporting clinical follow-up of ≥12 months. Main outcome measurements included (1) differential diagnoses and (2) performance characteristics of EUS-fine needle aspiration (FNA) for diagnosing neoplasm in patients with non-cystic pancreatic lesions with and without PD dilation.

RESULTS:

A neoplasm was finally diagnosed in 152 of 187 patients with and 87 of 258 patients without PD dilation on CT scan. Chronic pancreatitis (diffuse and focal) was the predominant non-malignant diagnosis in patients with PD dilation. In patients without PD dilation, malignant lesions included neuroendocrine tumor, adenocarcinoma, metastasis, PEComa (perivascular epitheloid cell tumor), and lymphoma; and the non-neoplastic diagnosis included chronic pancreatitis, intrapancreatic lymph nodes, and infected pancreatic fluid collection. EUS-FNA had 97.6% accuracy for diagnosing a neoplasm in these patients.

CONCLUSIONS:

Dilation PD proximal to a focal solid pancreatic lesion increases the likelihood of malignancy but the performance characteristics of this radiologic finding are probably inadequate to guide clinical management. Neoplasms without dilated PD often require immunostaining for a definitive diagnosis.

Use of EUS-FNA in diagnosing pancreatic neoplasm without a definitive mass on CT

BACKGROUND

Diagnosis of pancreatic neoplasm is challenging in patients with inconclusive findings on pancreatic multidetector row CT (MDCT).

OBJECTIVE

To determine the diagnostic accuracy and to identify predictors of pancreatic neoplasm by EUS with FNA in this setting.

DESIGN

Retrospective chart review during the study period of January 2002 to December 2010.

SETTING

Tertiary referral center.

PATIENTS

Of the 1046 patients who underwent pancreatic EUS, 116 patients were selected because their clinical presentation was suspicious for pancreatic malignancy, but their MDCT findings were inconclusive.

INTERVENTION

EUS with FNA.

MAIN OUTCOME MEASUREMENTS

Diagnostic yield of malignancy and significance of clinical variables.

RESULTS

When surgical pathology or subsequent clinical course was used as the criterion standard, EUS with FNA had a sensitivity, specificity, positive predictive value, and accuracy of 87.3%, 98.3%, 98.5%, and 92.1%, respectively, in diagnosing a pancreatic neoplasm that was indeterminate on MDCT. Factors significantly associated with EUS detection of pancreatic ductal adenocarcinoma were total bilirubin level greater than 2 mg/dL (P < .001), CT finding of pancreatic duct dilation (P < .001), bile duct stricture (P < .001), and tumor size 1.5 cm or larger detected by EUS (P = .004). Among them, pancreatic duct dilation on CT (odds ratio 4.10; 95% confidence interval, 1.52-11.05), and tumor size 1.5 cm or larger detected by EUS (odds ratio 8.46; 95% confidence interval, 2.02-35.45) were independent risk factors.

LIMITATIONS

Retrospective design and patient referral bias.

CONCLUSIONS

When MDCT is indeterminate, EUS is a highly sensitive and accurate modality for the detection of pancreatic neoplasm, especially when the tumor is smaller than 2.0 cm.

Advanced EUS imaging for early detection of pancreatic cancer

Endoscopic ultrasound (EUS)-fine needle aspiration remains the gold standard for diagnosing pancreatic malignancy. However, in a subset of patients, limitations remain in regards to image quality and diagnostic yield of biopsies. Several new devices and processors have been developed that allow for enhancement of the EUS image. Initial studies of these modalities do show promise. However, cost, availability, and overall incremental benefit to EUS-fine needle aspiration have yet to be determined.

Current status on the diagnosis and evaluation of pancreatic tumor in Asia with particular emphasis on the role of endoscopic ultrasound

In Asia, the incidence of pancreatic cancer in some countries has been increasing. Owing to most cases being diagnosed late, prognosis for pancreatic cancer remains dismal. It is clear that the future for pancreatic cancer lies in early detection. While the possible presence of pancreatic masses is often first raised by non-invasive abdominal imaging, such as computerized tomography and magnetic resonance imaging, smaller lesions and locoregional lymph node metastases are often not detectable by these means. Endoscopic ultrasonography (EUS) offers a higher sensitivity (93-100%) for detection of small potentially curable pancreatic masses than other existing imaging modalities. It is also recommended for the evaluation of portal vein confluence, portal vein, celiac axis, and superior mesentric artery origin, and exclusion of resectability. Due to the closer proximity of EUS to the target structure, and lower rate of needle tract seeding, EUS-guided fine-needle aspiration of pancreatic mass is considered the most suitable tissue acquisition technique. Lastly, EUS also enables the performance of endoscopic interventions. Its performance can be further enhanced with newer techniques, including contrast-enhanced ultrasound and elastrography. It is anticipated that in the near future, molecular technologies may make it possible to detect microscopic amounts of cancer in tissue or blood, predict relapse and survival after therapy, as well as determine optimal therapy.

Ratio of pancreatic duct caliber to width of pancreatic gland by endosonography is predictive of pancreatic cancer

OBJECTIVES

This study aimed to determine whether (1) a pancreatic duct (PD) diameter to pancreatic gland width (G) ratio (PDG) by endoscopic ultrasonography (EUS) predicts pancreatic cancer (PC) and (2) whether this ratio better indicates PC compared to PD dilation alone.

METHODS

Patients presenting for EUS were classified into the following 4 categories: (1) normal, (2) noncalcific chronic pancreatitis (NCCP), (3) calcific CP (CCP), and (4) PC.

RESULTS

There were 198 patients enrolled. Final diagnoses were PC (n = 34), CCP (n = 16), and normal/NCCP (n = 148). The median PD diameter (8, 5, and 2 mm, respectively; P = <0.001), G (16, 20, and 17 mm, respectively; P = 0.002), and PDG ratio were significantly different among groups (0.54, 0.25, and 0.12, respectively; P < 0.001). Patients with PC were more likely to have a PDG ratio of greater than or equal to 0.34 compared to CCP, and normal/NCCP groups (94%, 19%, 1.3%, respectively; P < 0.001). The positive predictive value, negative predictive value, sensitivity, specificity, and accuracy of PDG greater than or equal to 0.34 for detecting cancer were 87%, 99%, 94%, 97%, and 97%, respectively. The accuracy and positive predictive value of PD dilation alone for diagnosing PC were 83% and 50%, respectively.

CONCLUSIONS

A PDG ratio is a good predictor of PC and is better than PD dilation. This sign should be routinely used by endosonographers to improve EUS diagnostic capability of PC.

The role of endoscopic ultrasound in biliary obstruction

The role of endoscopic ultrasound (EUS) in the diagnosis of biliary obstruction is well established, and emerging evidence suggests it may also play a therapeutic role. Differentiating between benign and malignant causes of biliary obstruction can be challenging, but EUS is a crucial tool in the armamentarium of the physician. Evolving technologies such as elastography and contrast enhancement may further supplement the diagnostic abilities of EUS. Therapeutic applications of EUS are evolving rapidly, and EUS-guided cholangiography may aid biliary decompression when endoscopic retrograde cholangiopancreatography (ERCP) has failed or is not possible.

Imaging of pancreatic cancer: An overview

Pancreatic cancer (PaCa) is the fourth leading cause of cancer-related death in the United States. The median size of pancreatic adenocarcinoma at the time of diagnosis is about 31 mm and has not changed significantly in last three decades despite major advances in imaging technology that can help diagnose increasingly smaller tumors. This is largely because patients are asymptomatic till late in course of pancreatic cancer or have nonspecific symptoms. Increased awareness of pancreatic cancer amongst the clinicians and knowledge of the available imaging modalities and their optimal use in evaluation of patients suspected to have pancreatic cancer can potentially help in diagnosing more early stage tumors. Another major challenge in the management of patients with pancreatic cancer involves reliable determination of resectability. Only about 10% of pancreatic adenocarcinomas are resectable at the time of diagnosis and would potentially benefit from a R0 surgical resection. The final determination of resectability cannot be made until late during surgical resection. Failure to identify unresectable tumor pre-operatively can result in considerable morbidity and mortality due to an unnecessary surgery. In this review, we review the relative advantages and shortcomings of imaging modalities available for evaluation of patients with suspected pancreatic cancer and for preoperative determination of resectability.