Agreement among Magnetic Resonance Imaging/Magnetic Resonance Cholangiopancreatography (MRI-MRCP) and Endoscopic Ultrasound (EUS) in the evaluation of morphological features of Branch Duct Intraductal Papillary Mucinous Neoplasm (BD-IPMN)

Comparison of Magnetic Resonance Imaging and Endoscopic Ultrasound in the Sizing of Intraductal Papillary Mucinous Neoplasia of the Pancreas

OBJECTIVES

Because IPMNs are potentially malignant, surveillance of IPMN is recommended by magnetic resonance imaging (MRI) and endoscopic ultrasound (EUS). The aim of the study was the evaluation of the concordance between EUS and MRI regarding cyst size.

METHODS

Retrospective data analysis was done for patients with IPMN in whom EUS and MRI were performed simultaneously (≤60 days). The measured cyst size of both procedures was compared by Bland-Altman plots. Agreement of cyst localization and dilation of main pancreatic duct was assessed using kappa statistics.

RESULTS

Fifty-nine cases were evaluated (median age, 71 years; 65% female; median time interval between both investigations, 17 days). The mean difference of IPMN maximal diameter between EUS and MRI was 0.55 mm with a prediction interval of -9.20 to +10.29 mm for 95% of the expected differences. There was strong interobserver agreement regarding cyst localization ( κ = 0.669, P = 1.06e -13 ) and the width of main pancreatic duct (<5, 5-9, and ≥10 mm; κ = 0.676 caput, κ = 0.823 corpus).

CONCLUSIONS

We found a clinically relevant difference in cyst size comparing EUS and MRI. Therefore, alternating EUS and MRI for follow-up of the "worrisome feature" size growth is not reasonable.

Clinical and Molecular Attributes and Evaluation of Pancreatic Cystic Neoplasm

Intraductal papillary mucinous neoplasms (IPMNs) and mucinous cystic neoplasms (MCNs) are all considered "Pancreatic cystic neoplasms (PCNs)" and show a varying risk of developing into pancreatic ductal adenocarcinoma (PDAC). These lesions display different molecular characteristics, mutations, and clinical manifestations. A lack of detailed understanding of PCN subtype characteristics and their molecular mechanisms limits the development of efficient diagnostic tools and therapeutic strategies for these lesions. Proper in vivo mouse models that mimic human PCNs are also needed to study the molecular mechanisms and for therapeutic testing. A comprehensive understanding of the current status of PCN biology, mechanisms, current diagnostic methods, and therapies will help in the early detection and proper management of patients with these lesions and PDAC. This review aims to describe all these aspects of PCNs, specifically IPMNs, by describing the future perspectives.

Identification of patients with branch-duct intraductal papillary mucinous neoplasm and very low risk of cancer: multicentre study

BACKGROUND

Different surveillance strategies for patients with low-risk branch-duct (BD) intraductal papillary neoplasm (IPMN) have been described. The aim of this study was to describe the natural history of low-risk BD-IPMN, and to identify risk factors for the development of worrisome features (WF)/high-risk stigmata (HRS) and of pancreatic malignancies.

METHODS

This was a multicentre retrospective study of patients with BD-IPMN who were under active surveillance between January 2006 and December 2015. Patients were eligible if they had a low-risk lesion and had a minimum follow-up of 24 months. Outcomes were development of WF/HRS or cytologically/histologically confirmed malignant IPMN.

RESULTS

Of 837 patients included, 168 (20 per cent) developed WF/HRS. At the end of the observation time, 132 patients (79 per cent) with WF/HRS were still under surveillance without progression to pancreatic cancer. Factors associated with the development of WF or HRS in multivariable analysis included localized nodules (versus diffuse: hazard ratio (HR) 0.43, 95 per cent c.i. 0.26 to 0.68), cyst size 15-19 mm (versus less than 15 mm: HR 1.88, 1.23 to 2.87) or at least 20 mm (versus less than 15 mm: HR 3.25, 2.30 to 4.60), main pancreatic duct size over 3 mm (versus 3 mm or less: HR 2.17, 1.41 to 3.34), and symptoms at diagnosis (versus no symptoms: HR 2.29, 1.52 to 3.45). Surveillance in an endoscopy-oriented centre was also associated with increased detection of WF or HRS (versus radiology-oriented: HR 2.46, 1.74 to 3.47).

CONCLUSION

Conservative management of patients with low-risk BD-IPMN is safe and feasible.

Diagnostic Accuracy of Magnetic Resonance Cholangiopancreatography to Detect Benign and Malignant Biliary Strictures

Background:

Magnetic resonance cholangiopancreatography (MRCP) is a noninvasive method to detect pancreaticobiliary strictures. In this study, we aimed to evaluate the diagnostic performance of MRCP and detect sensitive and specific radiologic features in distinguishing malignant and benign pathologies.

Materials and Methods:

In this study, 50 patients with biliary obstruction and a confirmed diagnosis using histopathology were included. The pathologies were evaluated using MRCP which were categorized into malignant and benign strictures. The etiology of strictures was detected using histopathology and endoscopic retrograde cholangiopancreatography. The diagnostic performance of MRCP was calculated using SPSS software. P < 0.05 was considered statistically significant.

Results:

Of 50 patients, 23 patients (46%) had malignant strictures based on MRCP and histopathology. The sensitivity and specificity of MRCP to detect malignancy were 95.7% and 96.3%, respectively. The most sensitive MRCP features to detect malignancy were upstream biliary duct dilation, abrupt tapering, and the presence of a solid mass with sensitivity 100%, 95.7%, and 78.2%, respectively. The malignancy rate was significantly higher in the strictures with length >11.5 mm or wall thickness >2.75 mm (P < 0.05).

Conclusion:

MRCP is a sensitive method to differentiate malignant lesions from benign pathologies. A long and thick stricture with the presence of a solid mass, upstream biliary duct dilation, and abrupt tapering is highly suggestive of malignancy.

Impact of Antibiotic Prophylaxis on Infection Rate after Endoscopic Ultrasound Through-the-Needle Biopsy of Pancreatic Cysts: A Propensity Score-Matched Study

Background: Despite weak evidence, antibiotic prophylaxis prior to endoscopic ultrasound-guided through-the-needle biopsy (EUS-TTNB) of pancreatic cystic lesions (PCLs) is routinely used in clinical practice. We aim to compare a group of patients treated with antibiotics before EUS-TTNB of PCLs and a group who did not undergo antimicrobial prophylaxis. Methods: Out of 236 patients with pancreatic cystic lesions referred to two high-volume centers between 2016 and 2021, after propensity score matching, two groups were compared: 98 subjects who underwent EUS-TTNB under antibiotic prophylaxis and 49 subjects without prophylaxis. Results: There was no difference in terms of baseline parameters between groups. Final diagnosis was serous cystadenoma in 36.7% of patients in the group not treated with prophylaxis and in 37.7% of patients in the control group, whereas IPMN and mucinous cystadenoma were diagnosed in 3 (6.1%) and 16 (32.6%) versus 6 (6.1%) and 32 (32.6%) patients in the two groups, respectively (p = 0.23). Overall, the adverse event rate was 6.1% in the group not treated with antibiotic prophylaxis and 5.1% in the control group (p = 0.49). Only a single infectious adverse event occurred in each group (p = 0.48). The diagnostic yields were 89.7% and 90.8% in the two groups (p = 0.7), and the diagnostic accuracy rate was 81.6% in both groups (p = 1.0). Conclusions: Prophylactic antibiotics do not seem to influence the risk of infection, and their routine use should be discouraged.

Narrative review of intraductal papillary mucinous neoplasms: pathogenesis, diagnosis, and treatment of a true precancerous lesion

OBJECTIVE

Although considerable progress has been made in our understanding of intraductal papillary mucinous neoplasm (IPMN) of the pancreas, there are still some problems to be solved.

BACKGROUND

IPMN is one of the most important precancerous lesions of pancreatic cancer, but the relationship between IPMN and pancreatic cancer, and the specific mechanism of the development from IPMN to invasive carcinoma, remain to be explored in depth. With the development of imaging, the detection rate of IPMN has been greatly improved. However, the degree of malignancy of IPMN is difficult to assess, and its classification criteria and surgical treatment strategies are still controversial. Therefore, there is an urgent need for the best treatment plan for IPMN and research that can better predict IPMN recurrence and tumor malignancy.

METHODS

From the online database Web of Science (https://webofknowledge.com/) and PubMed (https://pubmed.ncbi.nlm.nih.gov/), we use specific retrieval strategies to retrieve relevant articles based on the topics we discussed, and we review and discuss them.

CONCLUSIONS

This paper discusses the related research and progress of IPMN in recent years to improve the understanding of the incidence, diagnosis, treatment, and prognosis of this disease. The follow-up and monitoring of IPMN is particularly important, but the specific strategy also remains controversial.

Artificial intelligence in gastrointestinal radiology: A review with special focus on recent development of magnetic resonance and computed tomography

Artificial intelligence (AI), particularly the deep learning technology, have been proven influential to radiology in the recent decade. Its ability in image classification, segmentation, detection and reconstruction tasks have substantially assisted diagnostic radiology, and has even been viewed as having the potential to perform better than radiologists in some tasks. Gastrointestinal radiology, an important subspecialty dealing with complex anatomy and various modalities including endoscopy, have especially attracted the attention of AI researchers and engineers worldwide. Consequently, recently many tools have been developed for lesion detection and image construction in gastrointestinal radiology, particularly in the fields for which public databases are available, such as diagnostic abdominal magnetic resonance imaging (MRI) and computed tomography (CT). This review will provide a framework for understanding recent advancements of AI in gastrointestinal radiology, with a special focus on hepatic and pancreatobiliary diagnostic radiology with MRI and CT. For fields where AI is less developed, this review will also explain the difficulty in AI model training and possible strategies to overcome the technical issues. The authors’ insights of possible future development will be addressed in the last section.

Changing trends in the clinicopathological features, practices and outcomes in the surgical management for cystic lesions of the pancreas and impact of the international guidelines: Single institution experience with 462 cases between 1995-2018

INTRODUCTION

The impact on clinical practice of the international guidelines including the Sendai Guidelines (SG06) and Fukuoka Guidelines (FG12) on the management of cystic lesions of the pancreas (CLP) has not been well-studied. The primary aim was to examine the changing trends and outcomes in the surgical management of CLP in our institution over time and to determine the impact of these guidelines on our institution practice.

METHODS

462 patients with surgically-treated CLP were retrospectively reviewed and classified under the 2 guidelines. The cohort was divided into 3 time periods: 1998-2006, 2007-2012 and 2013 to 2018.

RESULTS

Comparison across the 3 time periods demonstrated significantly increasing frequency of older patients, asymptomatic CLP, male gender, smaller tumor size, elevated Ca 19-9, use of magnetic resonance imaging (MRI) and use of endoscopic ultrasound (EUS) prior to surgery. There was also significantly increasing frequency of adherence to the international guidelines as evidenced by the increasing proportion of HR^SG06 and HR^FG12 CLP with a corresponding lower proportion of LR^SG06 and LR^FG12 being resected. This resulted in a significantly higher proportion of resected CLP whereby the final pathology confirmed that a surgery was actually indicated.

CONCLUSIONS

Over time, there was increasing adherence to the international guidelines for the selection of patients for surgical resection as evidenced by the significantly increasing proportion of HR^SG06 and HR^FG06 CLPs undergoing surgery. This was associated with a significantly higher proportion of patients with a definitive indication for surgery. These suggested that over time, there was a continuous improvement in our selection of appropriate CLP for surgical treatment.

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.

MRI of the Pancreas

MRI has played a critical role in the evaluation of patients with pancreatic pathologies, from screening of patients at high risk for pancreatic cancer to the evaluation of pancreatic cysts and indeterminate pancreatic lesions. The high mortality associated with pancreatic adenocarcinomas has spurred much interest in developing effective screening tools, with MRI using magnetic resonance cholangiopancreatography (MRCP) playing a central role in the hopes of identifying cancers at earlier stages amenable to curative resection. Ongoing efforts to improve the resolution and robustness of imaging of the pancreas using MRI may thus one day reduce the mortality of this deadly disease. However, the increasing use of cross-sectional imaging has also generated a concomitant clinical conundrum: How to manage incidental pancreatic cystic lesions that are found in over a quarter of patients who undergo MRCP. Efforts to improve the specificity of MRCP for patients with pancreatic cysts and with indeterminate pancreatic masses may be achieved with continued technical advances in MRI, including diffusion-weighted and T₁ -weighted dynamic contrast-enhanced MRI. However, developments in quantitative MRI of the pancreas remain challenging, due to the small size of the pancreas and its upper abdominal location, adjacent to bowel and below the diaphragm. Further research is needed to improve MRI of the pancreas as a clinical tool, to positively affect the lives of patients with pancreatic abnormalities. This review focuses on various MR techniques such as MRCP, quantitative imaging, and dynamic contrast-enhanced imaging and their clinical applicability in the imaging of the pancreas, with an emphasis on pancreatic malignant and premalignant lesions. Level of Evidence 5 Technical Efficacy Stage 3 J. MAGN. RESON. IMAGING 2021;53:347-359.

The Role of Positron Emission Tomography in Clinical Management of Intraductal Papillary Mucinous Neoplasms of the Pancreas

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas represent a heterogeneous group of tumors, increasingly diagnosed in clinical practice. An early differential diagnosis between malignant and benign lesions is crucial to patient management and the choice of surgery or observation. The therapeutic approach is currently based on a patient’s clinical, biochemical, and morphological characteristics. The latest published International Consensus Guidelines (ICG) make no mention of the role of metabolic assessments of IPMNs. The aim of this study was to review the current literature, examining the role of 18-fluorodeoxyglucose (FDG) positron emission tomography (PET) in IPMN management. An extensive literature review was conducted according to the 2009 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and 10 articles were analyzed in detail, focusing on the value of PET as opposed to other standard imaging criteria. Data were retrieved on 419 patients. The 18-FDG-PET proved more sensitive, specific, and accurate than the ICG criteria in detecting malignant IPMNs (reaching 80%, 95%, and 87% vs. 67%, 58%, and 63%, respectively). Metabolic assessments may be used as an additional tool for the appropriate management of patients with doubtful imaging findings.

Statins decrease the risk of acute pancreatitis after endoscopic ultrasound fine-needle aspiration of pancreatic cysts

BACKGROUND

Basic and clinical studies suggest that statins may prevent and even ameliorate acute pancreatitis. The present study was to evaluate whether statin decreases the risk of acute pancreatitis in patients undergoing endoscopic ultrasound-guided fine-needle aspiration of pancreatic cysts.

METHODS

Out of 456 patients with pancreatic cysts referred to our center between 2006 and 2018, 365 were finally included in analyses: 86 were treated with statins and 279 were not at the time of endoscopic ultrasound fine-needle aspiration. We compared the acute pancreatitis incidence between the two groups, and we also compared other complications such as bleeding and infections.

RESULTS

Median age was 64 years [interquartile range (IQR) 62-69] and median cyst size was 24 mm (IQR, 21-29). The most frequent histology was intraductal papillary mucinous neoplasm (45.3% and 42.3% in the two groups, respectively; P = 0.98). All 13 patients experiencing post-endoscopic ultrasound acute pancreatitis were from the control group (4.7%), of which 3 were classified as severe pancreatitis. None of statin users developed post-procedural acute pancreatitis (odds ratio: 0.15; 95% confidence interval: 0.03-0.98; P = 0.03). No difference was registered with regard to severe pancreatitis and other complications.

CONCLUSIONS

Statins exert a beneficial role in preventing acute pancreatitis in patients with pancreatic cysts undergoing endoscopic ultrasound-guided fine-needle aspiration. If confirmed in prospective trials, our findings may pave the way to an extensive use of statins as prophylactic agents in pancreatic interventional endoscopy.

Intraductal papillary mucinous neoplasms of the pancreas and European guidelines: importance of the surgery type in the decision-making process

BACKGROUND

The European Consensus 2018 established a new algorithm with absolute and relative criteria for intraductal papillary mucinous neoplasms of the pancreas (IPMN) management. The aim of this study was to validate these criteria and analyse the outcomes in function of the surgical procedure and IPMN subtype.

METHODS

Clinical, radiological and surgical data (procedure, morbidity/mortality rates) of patients who underwent surgery for IPMN between 2007 and 2017. The predictive value of the different criteria was analysed.

RESULTS

124 patients (men 67%; mean age 65 years) underwent surgery for IPMN (n = 62 malignant tumours; 50%). Jaundice, cyst ≥4 cm and Wirsung duct size 5-9.9 mm or ≥ 10 mm were significantly associated with malignancy (4.77 < OR < 11.85 p < 0.0001). The positive predictive value of any isolated criterion ranged from 71 to 87%, whereas that of three relative criteria together reached 100%. The mortality and morbidity (grade III-IV complications according to the Dindo-Clavien classification) rates were 3 and 8%, respectively. Morbidity/mortality after duodenopancreatectomy and total pancreatectomy were significantly higher for benign IPMN (p = 0.01).

CONCLUSION

Considering the morbidity associated with extended surgery, particularly for benign IPMN, the results of the present study suggest that high-risk surgery should be considered only in the presence of three relative criteria and including the surgery type in the decision-making algorithm.

Antibiotics Do Not Decrease the Rate of Infection After Endoscopic Ultrasound Fine-Needle Aspiration of Pancreatic Cysts

BACKGROUND

In spite of the weak evidence, antibiotic prophylaxis prior to endoscopic ultrasound-guided fine-needle aspiration of pancreatic cystic lesions is routinely used in the clinical practice.

AIMS

To compare a group of patients treated with antibiotics before fine-needle aspiration of pancreatic cystic lesions and a group who did not undergo antimicrobial prophylaxis.

METHODS

Out of 335 patients with suspected pancreatic cystic lesions referred to our center between 2006 and 2018, after propensity score matching two groups were compared: 135 subjects who underwent endoscopic ultrasound fine-needle aspiration under antibiotic prophylaxis and 135 treated with no antimicrobial agents. Primary outcome was infection rate; secondary endpoints included other complications or antibiotic-related adverse events.

RESULTS

Median age was 64 (interquartile range 61-68) and median cyst size was 24 mm (22-28), with no difference between groups. Overall, 10 adverse events (7.1%) of which 2 serious (1.4%) were observed in the antibiotic group and 8 (5.8%) of which 1 (0.7%) serious in the non-antibiotic group. Cyst infection was observed in 2 patients (1.4%) in the antibiotic group and 3 patients (2.2%) in the other cohort (p = 0.65).

CONCLUSIONS

Prophylactic antibiotics do not seem to substantially reduce this risk of infection, and their routine use should be abandoned.