An updated review on ablative treatment of pancreatic cystic lesions

Portuguese Pancreatic Club Perspectives on Endoscopic Ultrasound-Guided and Surgical Treatment of Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors (panNETs) are a group of neoplasms with heterogenous biological and clinical phenotypes. Although historically regarded as rare, the incidence of these tumors has been increasing, mostly owing to improvements in the detection of small, asymptomatic tumors with imaging. The heterogeneity of these lesions creates significant challenges regarding diagnosis, staging, and treatment. Endoscopic ultrasound (EUS) has improved the characterization of pancreatic lesions. Furthermore, EUS nowadays has evolved from a purely diagnostic modality to allow the performance of minimally invasive locoregional therapy for pancreatic focal lesions. The choice of treatment as well as the treatment goals depend on several factors, including tumor secretory status, grading, staging, and patient performance status. Surgery has been the mainstay for the management of these patients, particularly for localized, low-grade, large panNETs >2 cm. Over the last decade, a significant body of evidence has been accumulated evaluating the role of EUS for the ablative therapy of panNETs, namely by the use of chemoablative agents and radiofrequency. Although endoscopic techniques are not routinely recommended by international guidelines, they may be considered for the treatment of smaller lesions in patients who are unwilling or unfit for pancreatic surgery. In this review, we summarize the existing evidence on the interventional techniques for the treatment of patients with panNETs, focusing on the EUS-guided and surgical approaches.

Endoscopic Ultrasound-Guided Ablation of Pancreatic Mucinous Cysts

Endoscopic ultrasound (EUS) has rapidly evolved from a diagnostic to a therapeutic tool with applications for various pancreaticobiliary diseases. As part of this evolution, EUS-guided chemoablation for neoplastic pancreatic cysts is developing as a minimally invasive treatment option for appropriately selected mucinous cysts, which can spare patients major resective surgery and may reduce progression to pancreatic cancer. Chemotherapeutic cyst ablation has demonstrated encouraging complete resolution rates, while an alcohol-free chemoablation protocol has demonstrated a significant decrease in adverse events without a compromise to complete ablation rates when compared with previous alcohol-based protocols. Most pancreatic cysts are small, low risk, and best managed by surveillance per accepted guidelines. Cysts with features suggestive of overt malignancy are best discussed by a multidisciplinary committee, and surgery is considered if appropriate. However, for patients in the middle ground with cysts that are structurally suitable for chemoablation, alcohol-free chemoablation has been shown to allow effective, safe, and durable results especially for those who are not ideal operative candidates. EUS-guided alcohol-free chemoablation is promising and continues to evolve; however, as a relatively novel treatment option it has areas of uncertainty that will require further investigation and development.

Successful EUS-guided pancreatic cyst chemoablation safely allows reduction in the frequency of radiographic surveillance: long-term follow-up of randomized prospective data

BACKGROUND AND AIMS

Endoscopic ultrasound-guided pancreatic cyst chemoablation is safe and effective for appropriately selected patients; however, the proper frequency of radiographic surveillance after successful chemoablation is unknown. Here we report the long-term follow-up of 2 randomized prospective Chemotherapy for Ablation and Resolution of Mucinous Pancreatic Cysts (ChARM) clinical trials. In addition, the performance of a postablation-reduced radiographic surveillance protocol was evaluated according to clinical and economic outcomes and patient experience metrics.

METHODS

Patients who successfully completed 1 of the 2 ChARM randomized control trials were evaluated for durability of response and clinical outcomes. Patients were eligible if 2 years or more of follow-up were available and complete. We calculated economic outcomes according to Medicare allowable costs applicable to endoscopic ultrasound, magnetic resonance imaging, and outpatient clinic visits. We modeled costs of a patient followed by the ChARM Post-treatment Reduced Radiographic Surveillance Protocol compared with a similar patient followed under Fukuoka or American College of Gastroenterology (ACG) guidelines over 5 years. In addition, patients under long-term surveillance in our clinic were interviewed via a 4-question Likert-type questionnaire.

RESULTS

A total of 52 patients were eligible and included in the study. At the most recent follow-up of the 52 patients, 36 (69.2%) achieved complete response, an additional 11 (21.2%) showed partial response, and only 5 (9.6%) showed nonresponse. All patients were successfully reduced to annual or less surveillance without recurrence or the development of cyst-associated malignancy. Compared with Fukukoa or ACG guidelines, a patient treated and followed under the ChARM Post-treatment Reduced Radiographic Surveillance Protocol incurred a Medicare allowable cost of $7200.00 versus $19,437.44 and $12,526.52 if untreated and observed under Fukukoa and ACG guidelines, respectively. The patient experience questionnaire was returned completed by 49 participants.

CONCLUSIONS

The ChARM Post-treatment Reduced Radiographic Surveillance Protocol safely allows a reduction in radiographic surveillance. A reduction in cost associated with cyst management under the ChARM protocol, compared with management following Fukukoa or ACG guidelines, was shown. According to the questionnaire, most patients reported a moderate level of logistical and emotional burden associated with magnetic resonance imaging surveillance, and a majority were in favor of reducing the frequency of radiographic surveillance if it could be done without a marked increase in oncologic risk.

Comparison of outcomes of EUS-guided ablation and surveillance only for pancreatic cystic lesions: a propensity score-matching study (with videos)

BACKGROUND AND AIMS

EUS-guided ethanol ablation is a recently introduced treatment approach for pancreatic cystic lesions (PCLs), including branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs). However, the utility of this procedure is limited because of its relatively low efficacy in treating PCLs.

METHODS

We retrospectively reviewed patients with PCLs, including those with enlarging suspected BD-IPMNs or those with PCLs measuring >3 cm, who were suboptimal candidates for surgery and had been managed using EUS-guided rapid ethanol lavage (EUS-REL; immediate ethanol lavage performed 4 times, 2015-2022) or surveillance only (SO; 2007- 2022). Propensity score matching (PSM) was performed to minimize bias. The primary outcome was the cumulative incidence rate of BD-IPMN progression. Secondary outcomes were the efficacy and safety of EUS-REL, surgical resection rate (SR), overall survival (OS), and disease-specific survival (DSS) in both groups.

RESULTS

Overall, 169 and 610 patients were included in the EUS-REL and SO groups, respectively. PSM created 159 matched pairs. The radiologic complete resolution rate after EUS-REL was 74%. Procedure-related pancreatitis in the EUS-REL group was 13.0% (n = 22; 19 mild and 3 moderate grade); no severe adverse events were reported. The 10-year cumulative incidence rate of BD-IPMN progression was significantly lower in the EUS-REL group than in the SO group (1.6% vs 21.2%; hazard ratio, 12.35; P = .003). EUS-REL showed a lower tendency of SR compared with that associated with SO. The rates of 10-year OS and 10-year DSS were comparable in both groups.

CONCLUSIONS

EUS-REL was associated with a significantly lower 10-year cumulative incidence rate of BD-IPMN progression and a lower tendency of SR, whereas its 10-year OS and DSS rates were similar to those of SO for PCLs. EUS-REL may be a viable alternative to SO for managing patients with enlarging suspected BD-IPMNs or those with PCLs >3 cm who are suboptimal candidates for surgery.

Therapeutic Endoscopic Ultrasound: Current Indications and Future Perspectives

The transcendence of endoscopic ultrasound (EUS) from diagnostic to therapeutic tool has revolutionized management options in the field of gastroenterology. Through EUS-guided methods, pancreaticobiliary obstruction can now be utilized as an alternative to surgical and percutaneous approaches. This modality also allows for gallbladder drainage in patients who are not ideal operative candidates. By utilizing its unique imaging capabilities, EUS also allows for drainage access points in cases of gastric outlet obstruction as well as windows to ablate pancreatic cystic lesions. As technical progress continues to evolve, interventional gastroenterology continues to push the envelope of minimally invasive therapeutic procedures in a multidisciplinary setting. In this comprehensive review, we set out to describe current indications and innovations through EUS.

EUS-guided intra-tumoral therapies

EUS-guided treatments for focal tumor lesions has been developed since 20 years using at onset of the technique mainly local and guided alcohol injection [1-4]. Pancreatic tumors are the most assessed targeted lesions for EUS treatment because of their accessibility and because EUS management could be a safe alternative to surgery. More and more pancreatic tumors are discovered mainly fortuitously due to the advances in conventional imaging (abdominal ultrasound, CT, MRI) resulting in the question of surgical management of an asymptomatic pancreatic lesion ("incidentaloma") [5-8]. The lesions detected include mostly pancreatic cystic neoplasms (PCN) and neuroendocrine tumors (NET) mainly well differentiated. Clinically, NET are mostly non-functional and do not induce secretory disorders [5-8]. Once their nature is yielded by diagnostic tests like EUS-FNA, incidental nonfunctional NET currently lead to difficult management when their largest diameter is less than 2 cm [2,4,9,10]. EUS-guided treatment for pancreatic adenocarcinoma have also been developed with recent prospective observational study and randomized control study [11,12]. Thus, therapeutic surgical choices could be challenged by EUS- guided treatment [2,4,9].

Endoscopic palliation of malignant biliary obstruction

Malignant biliary obstruction often presents with challenges requiring the endoscopist to assess the location of the lesion, the staging of the disease, the eventual resectability and patient preferences in term of biliary decompression. This review will focus on the different modalities available in order to offer the most appropriate palliation, such as conventional endoscopic retrograde cholangiopancreatography, endoscopic ultrasound guided biliary drainage as well as ablative therapies including photodynamic therapy or radiofrequency ablation.

Pancreatic Cystic Neoplasms

Early detection of high-risk pancreatic cystic lesions enables potentially curative surgical resection, and early detection of lesions without worrisome features may lead to appropriate surveillance. Regrettably, differentiating premalignant and malignant cysts from nonmalignant ones remains challenging. However, emerging additional diagnostic tools, including the needle biopsy with microforceps and needle-based confocal laser endomicroscopy, are of exciting potential along with cyst fluid analysis".

The global research status and trends of the application of endoscopic ultrasonography in pancreatic tumors over the last decades: A bibliometric study

Background

To describe the development process and structural relationships of scientific achievements in endoscopic ultrasonography (EUS) in pancreatic tumors over the past decades and to reveal the key research topics using bibliometric analysis.

Methods

All relevant publications covering the research of EUS in pancreatic tumors from 1984 to 2021 were involved through the Web of Science Core Collection. R-bibliometrix was used to conduct the bibliometric analysis, and VOSviewer software was used to explore the hot spots and networks related to this field.

Results

Between 1984 and 2021, 4071 publications were involved. The number of annual publications increased from 1 to 310. The United States contributed the most publications to this field (n=1433, 35.20%), followed by Japan (n=827, 20.31%) and Germany (n=319, 7.84%). There was active cooperation between countries/regions. Gastrointestinal Endoscopy (GIE) was the most productive journal and the most influential journal. Professor Giovannini M, who produced the most publications, had a great influence on this research. The focus in this field was clarified by analyzing the top 10 citations and co-citations publications. Moreover, the analysis of the keywords showed Important topics: "Classification of pancreatic tumor disease" "Development of EUS in the diagnosis of pancreatic tumor diseases," and "Development of EUS in the treatment of pancreatic tumor diseases."

Conclusion

For the first time, bibliometric analysis was used to gain a deep understanding of the global trends of studies investigating EUS in pancreatic tumor diseases. The EUS field is rapidly evolving, and our study may be a critical reference for clinical researchers related to this field.

Current updates and future directions in diagnosis and management of gastroenteropancreatic neuroendocrine neoplasms

Gastroenteropancreatic neuroendocrine neoplasms are a heterogenous group of rare neoplasms that are increasingly being discovered, often incidentally, throughout the gastrointestinal tract with varying degrees of activity and malignant potential. Confusing nomenclature has added to the complexity of managing these lesions. The term carcinoid tumor and embryonic classification have been replaced with gastroenteropancreatic neuroendocrine neoplasm, which includes gastrointestinal neuroendocrine and pancreatic neuroendocrine neoplasms. A comprehensive multidisciplinary approach is important for clinicians to diagnose, stage and manage these lesions. While histological diagnosis is the gold standard, recent advancements in endoscopy, conventional imaging, functional imaging, and serum biomarkers complement histology for tailoring specific treatment options. In light of developing technology, our review sets out to characterize diagnostic and therapeutic advancements for managing gastroenteropancreatic neuroendocrine tumors, including innovations in radiolabeled peptide imaging, circulating biomarkers, and endoscopic treatment approaches adapted to different locations throughout the gastrointestinal system.

State-of-the-Art Update of Pancreatic Cysts

Andrew Canakis.

The Durability of EUS-Guided Chemoablation of Mucinous Pancreatic Cysts: A Long-Term Follow-Up of the CHARM trial

Pancreatic cancer has known precursor lesions with potential to develop into malignancy over time. At least 20% of pancreatic cancer evolves from mucinous cystic neoplasms and intraductal papillary mucinous neoplasms, which are often discovered incidentally.^1,2 Current guidelines for the management of mucinous cystic neoplasms and intraductal papillary mucinous neoplasms include long-term surveillance, which is expensive and nontherapeutic, or surgical resection, which is associated with major risk and may not be an option for patients with significant concomitant illness.³.

Management of pancreatic cysts and guidelines: what the gastroenterologist needs to know

The prevalence of pancreatic cysts has increased significantly over the last decade, partly secondary to increased quality and frequency of cross-sectional imaging. While the majority never progress to cancer, a small number will and need to be followed. The management of pancreatic cysts can be both confusing and intimidating due to the multiple guidelines with varying recommendations. Despite the differences in the specifics of the guidelines, they all agree on several high-risk features that should get the attention of any clinician when assessing a pancreatic cyst: presence of a mural nodule or solid component, dilation of the main pancreatic duct (or presence of main duct intraductal papillary mucinous neoplasm), pancreatic cyst size ⩾3–4 cm, or positive cytology on pancreatic cyst fluid aspiration. Other important criteria to consider include rapid cyst growth (⩾5 mm/year), elevated serum carbohydrate antigen 19-9 levels, new-onset diabetes mellitus, or acute pancreatitis thought to be related to the cystic lesion.

Long-term outcome after EUS-guided radiofrequency ablation: Prospective results in pancreatic neuroendocrine tumors and pancreatic cystic neoplasms

Background and study aims  Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) for pancreatic neuroendocrine tumors (NETs) and intraductal pancreatic mucinous neoplasia (IPMN) with worrisome features or high-risk stigmata (WF/HRS) has been evaluated in few series with short-term outcomes. This study's primary endpoint was to assess the long-term efficacy of EUS-RFA in patients with NETs or pancreatic cystic neoplasms (PCNs) over at least 3 years. Patients and methods  Twelve patients had 14 NETs with a mean 13.4-mm size (10-20) and 17 patients had a cystic tumor (16 IPMN, 1 MCA) with a 29.1-mm mean size (9-60 were included. They were treated with EUS-guided RFA, evaluated prospectively at 1 year, and followed annually for at least 3 years. Results  The mean duration of follow-up was 42.9 months (36-53). Four patients died during follow-up (17-42 months) from unrelated diseases. At 1-year follow-up, and 85.7 % complete disappearance was seen in 12 patients with 14 NETs. At the end of follow-up (45.6 months), complete disappearance of tumors was seen in 85.7 % of cases. One case of late liver metastasis occurred in a patient with initial failure of EUS-RFA. At 1-year follow-up, a significant response was seen in 70.5 % of 15 patients with PCNs. At the end of the follow-up, there was a significant response in 66.6 % with no mural nodules. Two cases of distant pancreatic adenocarcinoma unrelated to IPMN occurred. Conclusions  EUS-RFA results for pancreatic NETs or PCNs appear to be stable during 42 months of follow-up.

Factors affecting the rates of adherence to surveillance recommendations for incidental pancreatic cystic lesions in a large urban safety net hospital

Background

Pancreatic cystic lesions (PCLs) are a heterogenous group of lesions with varying degrees of malignant potential. PCLs are often incidentally detected on imaging. Management for patients without an immediate indication for resection or tissue sampling entails radiographic surveillance to assess for features concerning for malignant transformation. This study aims to determine the rates of adherence to surveillance recommendations for incidental PCLs, and identify factors associated with adherence or loss of follow-up.

Methods

We conducted a single-centre retrospective study of patients at a tertiary safety net hospital with incidentally discovered asymptomatic PCLs. Follow-up was defined as having undergone repeat imaging as recommended in the radiology report. Data were analysed using logistic regression.

Results

Within our cohort (n=172), 123 (71.5%) subjects completed follow-up imaging. Attending a gastroenterology appointment was most strongly associated with completing follow-up for PCLs and remained significant (p=0.001) in a multivariate logistic regression model. Subjects without a documented primary care provider were less likely to have follow-up (p=0.028). Larger cyst size was associated with completion of follow-up in univariate only (p=0.067).

Conclusion

We found that follow-up of an incidentally discovered PCLs was completed in the majority of our subjects. Incomplete follow-up for PCLs occurred in up to one in three to four patients in our cohort. Access to primary care and utilisation of subspecialty gastroenterology care are associated with completion of follow-up for PCLs. If validated, our findings can guide potential interventions to improve follow-up rates for PCLs.

Diagnostic value of SpyGlass for pancreatic cystic lesions: comparison of EUS-guided fine-needle aspiration and EUS-guided fine-needle aspiration combined with SpyGlass

BACKGROUND AND AIMS

No study has evaluated the diagnostic value of SpyGlass by comparing SpyGlass results and non-SpyGlass results. In this retrospective study, we aimed to compare the diagnostic value of EUS-guided fine-needle aspiration (EUS-FNA) and EUS-FNA combined with SpyGlass to evaluate whether SpyGlass is valuable for increasing the diagnostic yield of EUS-FNA.

METHODS

From April 2015 to April 2020, 251 patients suspected of having pancreatic cystic lesions (PCLs) by imaging techniques who then underwent EUS-FNA were retrospectively enrolled. Only 98 patients who underwent surgical resection with a pathological diagnosis of pancreatic cystic lesion (PCL) were studied. The diagnostic performance outcomes were compared between the EUS-FNA group (EUS-FNA alone, n = 40) and the SpyGlass group (EUS-FNA combined with SpyGlass, n = 58) to assess the value of SpyGlass in diagnosing PCLs.

RESULTS

There were 71 females and 27 males with an overall mean age of 47.6 years. The median diameter of the PCLs was 42.2 mm (range, 11.4-100.0 mm). Approximately 37 cysts were localized in the head/neck of the pancreas, while 61 in the body/tail. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of the EUS-FNA group were 96.4% (27/28), 83.3% (10/12), 93.1% (27/29), 90.9% (10/11) and 92.5% (37/40), while those in the SpyGlass group were 100% (54/54), 75% (3/4), 98.2% (54/55), 100% (3/3) and 98.3% (57/58), respectively. The diagnostic accuracy rate in the SpyGlass group was higher than that in the EUS-FNA group; however, no significant difference was found between the two groups (P = 0.368). The diagnostic accuracy of evaluating specific cyst types in the EUS-FNA group was 85% (34/40), similar to that in the SpyGlass group (85.0% vs 84.5%, P = 0.944).

CONCLUSION

SpyGlass seems less valuable for the diagnosis of PCLs when EUS and EUS-FNA have been performed by experienced endoscopists.

Endoscopic Ultrasound

Endoscopic ultrasound provides high-resolution, real-time imaging of the gastrointestinal tract and surrounding extramural structures. In recent years, endoscopic ultrasound has played an increasing role as an adjunct or alternative method to conventional surgical therapies. The role of endoscopic ultrasound in diagnosis and management of gastrointestinal malignancy, pancreatic diseases, and biliary diseases continues to evolve. Therapeutic endoscopic ultrasound procedures for a variety of pancreatic and biliary indications shows a high technical and clinical success rate, with low rate of adverse events. Endoscopic ultrasound plays a key role in multidisciplinary management of complex surgical and oncology patients and those with pancreaticobiliary disorders.

Endoscopic ultrasound-guided injective ablative treatment of pancreatic cystic neoplasms

With the development of cross-sectional imaging modalities and the increasing attention being paid to physical examinations, the prevalence of pancreatic cystic neoplasms (PCNs) has increased. PCNs comprise a broad differential spectrum with some PCNs having low or no malignant potential and others having high malignant potential. The morbidity and mortality rates related to major pancreatic surgical resection are high. Long-term surveillance may not only increase the financial burden and psychological stress for patients but also result in a missed malignancy. Minimally invasive endoscopic ultrasound (EUS)-guided ethanol ablation was first reported in 2005. Several other agents, such as paclitaxel, lauromacrogol, and gemcitabine, were reported to be effective and safe for the treatment of PCNs. These ablative agents are injected through a needle inserted into the cyst via transgastric or transduodenal puncture. This treatment method has been substantially developed in the last 15 years and is regarded as a promising treatment to replace surgical resection for PCNs. While several reviews of EUS-guided ablation have been published, no systematic review has evaluated this method from patient preparation to follow-up in detail. In the present review, we systematically describe EUS-guided injective ablation with regard to the indications, contraindications, preoperative treatment, endoscopic procedure, postoperative care and follow-up, evaluation method, treatment efficiency, safety profile, tips and tricks, and current controversies and perspectives.