EUS-guided radiofrequency ablation as an alternative to surgery for pancreatic neuroendocrine neoplasms: Who should we treat?

Endoscopic ultrasound-guided ethanol ablation versus surgical resection of insulinomas

PURPOSE

Insulinoma is a rare tumor of the pancreas that can lead to hypoglycemia. To date, the standard therapy is surgical resection. After the first case report of successful endoscopic ultrasound-guided (EUS) ethanol injection 16 years ago, the need for establishing an alternative treatment method remains unchanged given the high morbidity rates of surgery and its unsuitability in some patients.

MATERIALS AND METHODS

Here, we provide retrospective data from 33 insulinoma patients that were treated at our center between 2010 and 2021. Of these, 9 patients were treated with EUS-guided ethanol injection and 24 underwent pancreatic surgery.

RESULTS

The ethanol group was older (ethanol: mean ± SE 67.8±11.2 years vs. surgery: 52.3±15.7, p=0.014) with a higher Charlson Comorbidity Index (3.0 (1.0;4.0) vs. 1.0 (0.0;2.0), p=0.008). The lowest glucose values were similar between groups before (ethanol: 2.09±0.17 mmol/l vs. surgery: 1.81±0.08, p=0.158) and after (4.95±0.74 vs. 5.41±0.28, p=0.581) the respective treatments. Complications occurred more frequently in the surgery group (11 % vs. 54 %, p=0.026). One patient after prior partial pancreatectomy died postoperatively. The hospitalization time was significantly shorter in the ethanol group (4.78±0.78 days vs. 19.88±4.07, p<0.001).

CONCLUSION

EUS-guided ethanol injection can be similarly effective for the treatment of hyperinsulinemic hypoglycemia compared with pancreatic surgery but seems to be associated with less severe complications. This implies the need for prospective randomized trials in insulinoma patients with a low risk for malignancy.

Radiofrequency ablation for the management of symptomatic pancreatic insulinomas

Background and Aims

Insulinomas are among the most common types of functional pancreatic neuroendocrine tumors and can cause debilitating, recurrent, symptomatic hypoglycemia. Pancreatic resection can be curative, but many patients are not candidates for major pancreatic surgery. EUS-guided radiofrequency ablation (EUS-RFA) is a novel minimally invasive technique for ablation of pancreatic tumors.

Methods

In this article and accompanying video, we describe the EUS-RFA ablation device, provide instructions for device setup, and review outcomes of a case series of EUS-RFA for symptomatic insulinomas. We also review the current literature describing EUS-RFA for symptomatic pancreatic insulinomas.

Results

This series of patients in the United States, as well as studies performed in other countries, suggests normalization of insulin levels that appears to be sustained over months to years following the procedure. There has been a favorable adverse event profile in the case series reported to date.

Conclusions

EUS-RFA is emerging as a promising option for the management of symptomatic insulinomas, particularly for patients who are poor surgical candidates or who decline surgery.

Endoscopic ultrasound-guided radiofrequency ablation of pancreatic insulinoma: a state of the art review

INTRODUCTION

Insulinomas are the most common functional pancreatic neuroendocrine tumors (PNETs) that lead to incapacitating hypoglycemia. Guidelines recommend surgical resection as the mainstay of management. However, surgery is fraught with complications, causing significant peri/post-operative morbidity. Since insulinomas are usually benign, solitary, small (<2 cm), and do not need lymphadenectomy, hence, in this regard, endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) is now being increasingly performed, to circumvent these adverse events and impairment of pancreatic function.

AREAS COVERED

A comprehensive literature search was undertaken across various databases (PubMed/MEDLINE, Embase, Scopus), with no language restriction, for relevant articles (case series, reviews, case reports) pertaining to EUS-RFA for insulinoma and PNETs, till October 2023. In this review, we have explicated the role of EUS-RFA for insulinoma management, detailing thoroughly its mechanism of action, EUS-RFA devices with data on its safety and efficacy, and an algorithmic approach for its management.

EXPERT OPINION

EUS-RFA is being advocated as a 'mini-invasive' option with the potential to replace surgery as a first-line approach for benign, sporadic, solitary, and small (<2 cm) insulinomas. Under real-time guidance, EUS-RFA has immense precision, is safe, predictable, with acceptable safety profile. Presently, it is being frequently performed for high-risk or inoperable candidates. Current need-of-the-hour is a randomized controlled trial to substantiate its role in the therapeutic algorithm for insulinoma management.

Endoscopic Ultrasound-guided Radiofrequency Ablation Versus Surgical Resection for Treatment of Pancreatic Insulinoma

BACKGROUND & AIMS

Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) is emerging as a safe and effective treatment for pancreatic neuroendocrine tumors. We aimed to compare EUS-RFA and surgical resection for the treatment of pancreatic insulinoma (PI).

METHODS

Patients with sporadic PI who underwent EUS-RFA at 23 centers or surgical resection at 8 high-volume pancreatic surgery institutions between 2014 and 2022 were retrospectively identified and outcomes compared using a propensity-matching analysis. Primary outcome was safety. Secondary outcomes were clinical efficacy, hospital stay, and recurrence rate after EUS-RFA.

RESULTS

Using propensity score matching, 89 patients were allocated in each group (1:1), and were evenly distributed in terms of age, sex, Charlson comorbidity index, American Society of Anesthesiologists score, body mass index, distance between lesion and main pancreatic duct, lesion site, size, and grade. Adverse event (AE) rate was 18.0% and 61.8% after EUS-RFA and surgery, respectively (P < .001). No severe AEs were observed in the EUS-RFA group compared with 15.7% after surgery (P < .0001). Clinical efficacy was 100% after surgery and 95.5% after EUS-RFA (P = .160). However, the mean duration of follow-up time was shorter in the EUS-RFA group (median, 23 months; interquartile range, 14-31 months vs 37 months; interquartile range, 17.5-67 months in the surgical group; P < .0001). Hospital stay was significantly longer in the surgical group (11.1 ± 9.7 vs 3.0 ± 2.5 days in the EUS-RFA group; P < .0001). Fifteen lesions (16.9%) recurred after EUS-RFA and underwent a successful repeat EUS-RFA (11 patients) or surgical resection (4 patients).

CONCLUSION

EUS-RFA is safer than surgery and highly effective for the treatment of PI. If confirmed in a randomized study, EUS-RFA treatment can become first-line therapy for sporadic PI.

Endoscopic Ultrasound-Guided Locoregional Treatments for Solid Pancreatic Neoplasms

Solid pancreatic neoplasms are one of the most diagnosed gastrointestinal malignancies thanks to the current and progressive advances in radiologic methods. Endoscopic ultrasound-guided techniques have over time gained a prominent role in the differential diagnosis and characterization of these pancreatic lesions, including pancreatic cancer, neuroendocrine tumors, and metastases. Recently, several endoscopic ultrasound-guided locoregional treatment techniques, which are divided into thermal ablative techniques and non-thermal injection techniques, have been developed and applied in different settings for the treatment of solid pancreatic neoplasms. The most common ablative techniques are radiofrequency, microwave, laser, photodynamic therapy and hybrid techniques such as hybrid cryothermal ablation. The most common injection techniques are ethanol injection, immunotherapy and brachytherapy. In this review, we update evidence about the efficacy and safety of endoscopic ultrasound-guided locoregional treatments for solid pancreatic neoplasms.

Radiofrequency ablation for pancreatobiliary disease: an updated review

Endoscopic radiofrequency ablation (RFA) has emerged as a minimally invasive treatment option in cases of malignant biliary obstruction, pancreatic cancer, and other pancreatic cystic neoplasms. Intraductal biliary RFA is safe, effective, and confers a survival advantage over stenting alone, where it should be used an adjunct to biliary stenting. Endoscopic ultrasound-guided RFA can also provide pancreatic cyst resolution in patients who are not ideal operative candidates. The aim of this review is to describe the endoscopic applications and associated outcomes of RFA.

Risk factors for EUS-guided radiofrequency ablation adverse events in patients with pancreatic neoplasms: a large national French study (RAFPAN study)

BACKGROUND AND AIMS

EUS-guided radiofrequency ablation (EUS-RFA) has been described as a potentially curative option for solid and cystic pancreatic neoplasms. We aimed to assess the safety and efficacy of pancreatic EUS-RFA in a large study population.

METHODS

A retrospective study retrieving all consecutive patients who underwent pancreatic EUS-RFA during 2019 and 2020 in France was conducted. Indication, procedural characteristics, early and late adverse events (AEs), and clinical outcomes were recorded. Risk factors for AEs and factors related to complete tumor ablation were assessed on univariate and multivariate analyses.

RESULTS

One hundred patients (54% men, 64.8 ± 17.6 years old) affected by 104 neoplasms were included. Sixty-four neoplasms were neuroendocrine neoplasms (NENs), 23 were metastases, and 10 were intraductal papillary mucinous neoplasms with mural nodules. No procedure-related mortality was observed, and 22 AEs were reported. Proximity of pancreatic neoplasms (≤1 mm) to the main pancreatic duct was the only independent risk factor for AEs (odds ratio [OR), 4.10; 95% confidence interval [CI), 1.02-15.22; P = .04). Fifty-nine patients (60.2%) achieved a complete tumor response, 31 (31.6%) a partial response, and 9 (9.2%) achieved no response. On multivariate analysis, NENs (OR, 7.95; 95% CI, 1.66-51.79; P < .001) and neoplasm size <20 mm (OR, 5.26; 95% CI, 2.17-14.29; P < .001) were independently related to complete tumor ablation.

CONCLUSIONS

The results of this large study confirm an overall acceptable safety profile for pancreatic EUS-RFA. Close proximity (≤1 mm) to the main pancreatic duct represents an independent risk factor for AEs. Good clinical outcomes in terms of tumor ablation were observed, especially for small NENs.

Study protocol for a multicenter randomized controlled trial to compare radiofrequency ablation with surgical resection for treatment of pancreatic insulinoma

BACKGROUND

Insulinoma is the most common functional pancreatic neuroendocrine tumor and treatment is required to address symptoms associated with insulin hypersecretion. Surgical resection is effective but burdened by high rate of adverse events (AEs). Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) demonstrated encouraging results in terms of safety and efficacy for the management of these tumors. However, studies comparing surgery and EUS-RFA are lacking.

AIMS

The primary aim is to compare EUS-RFA with surgery in term of safety (overall rate of AEs). Secondary endpoints include: (a) severe AEs rate; (b) clinical effectiveness; (c) patient's quality of life; (d) length of hospital stay; (e) rate of local/distance recurrence; (f) need of reintervention; (g) rate of endocrine and exocrine pancreatic insufficiency; (h) factors associated with EUS-RFA related AEs and clinical effectiveness.

METHODS

ERASIN-RCT is an international randomized superiority ongoing trial in four countries. Sixty patients will be randomized in two arms (EUS-RFA vs surgery) and outcomes compared. Two EUS-RFA sessions will be allowed to achieve symptoms resolution. Randomization and data collection will be performed online.

DISCUSSION

This study will ascertain if EUS-RFA can become the first-line therapy for management of small, sporadic, pancreatic insulinoma and be included in a step-up approach in case of clinical failure.

An Overview of Pancreatic Neuroendocrine Tumors and an Update on Endoscopic Techniques for Their Management

The growing importance of advanced endoscopy in the diagnosis and treatment of pancreatic neuroendocrine neoplasms (PanNETs) necessitates a comprehensive understanding of various biochemical markers, genetic testing methods, radiological techniques, and treatment approaches that encompass multiple disciplines within and beyond gastrointestinal oncology. This review aims to highlight key aspects of these topics, with a specific focus on emerging EUS-guided procedures for the management of PanNETs.

Endoscopic Ultrasound-Guided Local Ablative Therapies for the Treatment of Pancreatic Neuroendocrine Tumors and Cystic Lesions: A Review of the Current Literature

Since its emergence as a diagnostic modality in the 1980s, endoscopic ultrasound (EUS) has provided the clinician profound access to gastrointestinal organs to aid in the direct visualization, sampling, and subsequent identification of pancreatic pathology. In recent years, advancements in EUS as an interventional technique have promoted the use of local ablative therapies as a minimally invasive alternative to the surgical management of pancreatic neuroendocrine tumors (pNETs) and pancreatic cystic neoplasms (PCNs), especially for those deemed to be poor operative candidates. EUS-guided local therapies have demonstrated promising efficacy in addressing a spectrum of pancreatic neoplasms, while also balancing local adverse effects on healthy parenchyma. This article serves as a review of the current literature detailing the mechanisms, outcomes, complications, and limitations of EUS-guided local ablative therapies such as chemical ablation and radiofrequency ablation (RFA) for the treatment of pNETs and PCNs, as well as a discussion of future applications of EUS-guided techniques to address a broader scope of pancreatic pathology.

Approaching Small Neuroendocrine Tumors with Radiofrequency Ablation

In recent years, small pancreatic neuroendocrine tumors (pNETs) have shown a dramatic increase in terms of incidence and prevalence, and endoscopic ultrasound (EUS) radiofrequency ablation (RFA) is one potential method to treat the disease in selected patients. As well as the heterogeneity of pNET histology, the studies reported in the literature on EUS-RFA procedures for pNETs are heterogeneous in terms of ablation settings (particularly ablation powers), radiological controls, and radiological indications. The aim of this review is to report the current reported experience in EUS-RFA of small pNETs to help formulate the procedure indications and ablation settings. Another aim is to evaluate the timing and the modality of the radiological surveillance after the ablation. Moreover, new studies on large-scale series are needed in terms of the safety and long-term oncological efficacy of RFA on these small lesions.

Cushing Syndrome due to a Pancreatic Neuroendocrine Tumor Treated With Radiofrequency Ablation

Delayed diagnosis of Cushing syndrome (CS) results in advanced disease, treatment delays, and poor outcomes. We present a patient with ectopic ACTH syndrome (EAS) from a pancreatic neuroendocrine tumor (NET) whose care posed diagnostic and therapeutic challenges. A 59-year-old female with classic Cushing stigmata, biochemical evidence of ACTH-dependent hypercortisolism, and a 5-mm pituitary lesion presented for inferior petrosal sinus sampling, which was contraindicated due to non-ST elevation myocardial infarction and acute/subacute strokes. Whole-body computed tomography (CT) scan was unrevealing, but elevations in chromogranin A and proopiomelanocortin (POMC) concentrations suggested EAS. Positron emission tomography-CT with gallium 68-DOTATATE demonstrated a 7-mm pancreatic tail lesion, suspicious for a pancreatic NET. The patient was not a surgical candidate and treatment with ketoconazole was complicated by hepatoxicity. Endoscopic ultrasound-guided biopsy and radiofrequency ablation of the lesion was pursued. Pathology confirmed ACTH immunoreactive low-grade pancreatic NET. Post procedure, sustained normalization of ACTH and cortisol was achieved. This case supports the utility of POMC measurements in the differential diagnosis of CS and the use of advanced nuclear imaging for tumor localization. For patients with functional pancreatic NET who are poor surgical candidates or intolerant of pharmacotherapy, novel endoscopic ablation may offer a low-risk therapeutic option and should be further investigated.

Efficacy and Safety of Endoscopic Ultrasound-Guided Radiofrequency Ablation for Pancreatic Neuroendocrine Tumors: A Systematic Review and Metanalysis

Introduction: The development of dedicated endoscopes and the technical evolution of endoscopic ultrasound (EUS) have allowed a direct approach to pancreatic neoplastic lesions both for diagnosis and treatment. Among the more promising targets are pancreatic neuroendocrine tumors (Pan-NETs). Aim: to describe the evolution of endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) with particular attention to the treatment of PanNETs, focusing on safety and clinical efficacy of the technique. Methods: MEDLINE, Scopus, and Cochrane Library databases were searched for studies reporting about EUS-RFA for the treatment of PanNETs. Studies with outcomes of interest were selected and results were reported to describe clinical success, complications, fol-low-ups, and electrodes used. Clinical success was defined as the disappearance of clinical symp-toms for functional (F-) PanNETs and as complete ablation per nonfunctional (NF)-PanNETs. The pooled data were analyzed by a random-effects model. Results: Nineteen studies were selected, including 183 patients (82 males, 44.8%) with 196 lesions (101 F-PanNETs and 95 NF-PanNETs). Pooled estimates for the overall AE rates for the clinical efficacy were 17.8% (95% CI 9.1-26.4%) and 95.1% (95% CI 91.2-98.9%) for F-PanNETs and 24.6% (95% CI 7.4-41.8%) and 93.4% (95% CI 88.4-98.4%) for NF-PanNETs. Conclusions: EUS-RFA appears to be a mini-invasive technique with a good safety and efficacy profile for the treatment of F- and NF-PanNETs. EUS-RFA could be of-fered as possible alternative to surgery for the treatment of low-grade NF- or F-PanNETs, especially for those patients that are not eligible or are at high-risk for surgery.

A Review on Endoscopic Ultrasound-Guided Radiofrequency Ablation (EUS-RFA) of Pancreatic Lesions

The morbidity associated with pancreatectomies limits surgical options for high-risk patients with pancreatic neoplasms that warrant resection. Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) offers a minimally invasive and potentially definitive means to treat pancreatic neuroendocrine tumors and precancerous pancreatic cystic lesions. In addition, EUS-RFA may play a role in the treatment and palliation of non-surgical cases of pancreatic adenocarcinoma. The efficacy of RFA appears to be further enhanced by systemic immunomodulatory effects. Here, we review current studies on the developing role of EUS-RFA in these pancreatic pathologies.

Reliability of grading preoperative pancreatic neuroendocrine tumors on EUS specimens: a systematic review with meta-analysis of aggregate and individual data

BACKGROUND AND AIMS

Therapy and prognosis of pancreatic neuroendocrine tumors (PanNETs) are strictly related to the Ki-67 index, which defines tumor grading. The criterion standard for the assessment of grading of PanNETs is EUS-guided FNA (EUS-FBAFNA) or EUS-guided fine-needle biopsy sampling (EUS-FNB). Because data on diagnostic accuracy of EUS-FNA and EUS-FNB are heterogeneous, we aimed to analyze the variability in concordance between EUS grading and surgical grading.

METHODS

The MEDLINE, SCOPUS, and EMBASE databases were searched until November 2021 to identify studies reporting the concordance rate between EUS grading and surgical grading. The study was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Pooled events were calculated using a random-effects model and expressed in terms of pooled prevalence rates. A multivariate meta-regression was performed to find possible sources of heterogeneity. Where available, individual data were analyzed.

RESULTS

Twenty-six studies with 864 patients undergone EUS-FNA or EUS-FNB and surgical resection for PanNETs were included. The pooled estimate rate for the overall concordance of EUS grading and surgical grading was 80.3% (95% confidence interval, 75.6-85.1). Undergrading (EUS grading < surgical grading) was significantly more frequent with respect to overgrading (14.7% vs 3.5%, P < .001). Individual data analysis showed that among nonconcordant patients, the median Ki-67 difference was 3% (interquartile range, 2-6.15). The type of World Health Organization classification adopted and the median lesion diameter were significantly associated with heterogeneity at meta-regression.

CONCLUSIONS

EUS is an accurate technique in defining grading in patients with PanNETs, but a margin of error still exists, which should be the focus of future studies to minimize the risk of over- and/or undertreatment.

Endoscopic ultrasound-guided radiofrequency ablation of premalignant pancreatic-cystic neoplasms and neuroendocrine tumors: prospective study

BACKGROUND

Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) is a developing therapeutic approach for premalignant pancreatic-cystic neoplasms (PCNs) and small pancreatic neuroendocrine tumors (PNETs). The safety and efficacy of pancreatic EUS-RFA were previously reported in small series. Herein we report our initial experience with RFA of PCNs and small PNETs.

METHODS

This is a prospective single-center study including 12 patients with a median follow-up of 7 months, with either PCN or PNET &amp;lt;2 cm. Eligible PCNs were either intraductal papillary mucinous neoplasms (IPMN) with worrisome features or mucinous cystic neoplasms (MCN) that were not eligible or refused surgery. Ablation was performed using a 19-gauge dedicated needle.

RESULTS

Twelve patients were treated, five had PCNs (four IPMNs, one MCN; median size of 36 mm, range 12-60) and seven had PNETs (median size 8.9 mm, range 6-18). Among patients with PCNs, the complete radiologic response was achieved in 3/5 (60%), partial response in 1/5 (20%) and failure in 1/5 (20%). Among six patients with nonfunctioning PNETs, the complete radiologic response was achieved in 4/6 (66.7%), partial radiologic response in 0/6 (0%) and failure in 2/6 (33.3%). Following a median follow-up of 7 months. One patient with insulinoma showed complete resolution of hypoglycemia-related symptoms. Three postprocedural adverse events occurred, including one case (1/12, 8.3%) of mild acute pancreatitis and two cases (2/12, 16.7%) of abdominal pain.

CONCLUSION

EUS-guided RFA for premalignant PCNs and PNETs is feasible and well-tolerated. Efficacy would be further evaluated with continued follow-up of patients.

Management of non-functional pancreatic neuroendocrine tumors by endoscopic ultrasound-guided radiofrequency ablation: Retrospective study in two tertiary centers

BACKGROUND

Recently, there has been growing interest in investigating endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) for the management of small non-functional pancreatic neuroendocrine tumors (nf pNETs).

PATIENTS AND METHODS

A bicentric retrospective study was performed that included patients with histologically confirmed nf pNETs who were consecutively treated by EUS-RFA between December 2015 and March 2021 at two tertiary referral centers.

RESULTS

In 27 patients (mean age 65.0 years, 52% male), EUS-RFA was successfully performed. All patients had sporadic G1 lesions (mean size 14.0 ± 4.6 mm, 7% uncinated process, 22% head, 11% body, 19% body/tail junction, and 41% tail). Overall, 9/27 lesions (33%) were cystic. The mean hospital stay was 3.2 days. Complete treatment response was confirmed in 25/27 patients (93%) on cross-sectional imaging (mean follow-up 15.7 ± 12.2 months, range 2-41 months). Two patients had two EUS-RFA sessions until complete necrosis was observed. Periprocedural acute pancreatitis occurred in 4/27 (14.8%), three of them were treated by endoscopic cystogastrostomy (11.1%). One patient underwent secondary surgery. The histopathology of the resected specimen revealed 3 mm of residual tumor tissue.

CONCLUSION

EUS-RFA seems to be a promising treatment strategy for the management of small nf pNETs with excellent efficacy. Further evidence focusing on long-term survival, safety profile and recurrence is needed.

Pancreatic neuroendocrine carcinoma with unique morphological features mimicking intraductal papillary mucinous carcinoma: A case report

Background

Pancreatic neuroendocrine carcinoma (PanNEC) is a rare disease entity with rapid progression and poor prognosis. Here, we report a PanNEC case with unique morphological features mimicking intraductal papillary mucinous carcinoma.

Case presentation

A 69-year-old Japanese man was referred to our hospital for further evaluation of weight loss and deterioration of diabetes mellitus. Contrast-enhanced computed tomography showed a solid and cystic mass with hypo-enhancement at the tail of the pancreas. The main pancreatic duct (MPD) was diffusely dilated without obstruction, accompanied by marked parenchymal atrophy. Multiple peritoneal and omental nodules were observed, suggesting tumor dissemination. Endoscopic retrograde cholangiopancreatography revealed that the mass correlated with the dilated MPD. During pancreatography, a large amount of mucus was extruded from the pancreatic orifice of the ampulla. Based on these imaging findings, intraductal papillary mucinous carcinoma was suspected. Per-oral pancreatoscopy (POPS)-guided tumor biopsies were conducted for the lesion's solid components. Histopathological examination of the biopsied material confirmed small-cell-type PanNEC with a Ki-67 labeling index of 90%. Due to his condition's rapid decline, the patient was given the best supportive care and died 28 days after diagnosis.

Conclusion

Although rare, PanNEC, which correlates with the MPD and is accompanied by marked dilation of the MPD, does exist as one phenotype. In such cases, POPS-guided biopsy could be a useful diagnostic modality.

Endoscopic ultrasound radiofrequency ablation of pancreatic insulinoma in elderly patients: Three case reports

BACKGROUND

Endoscopic ultrasound (EUS)-guided radiofrequency ablation (RFA) has recently been proposed as a local treatment for functional pancreatic neuroendocrine neoplasms in patients unfit for surgery, in order to obtain clinical syndrome regression. Data on the safety and long-term effectiveness of this approach are scarce, and EUS-RFA procedures are not standardized.

CASE SUMMARY

The present case series reports 3 elderly patients with a pancreatic insulinoma and comorbidities, locally treated by EUS-guided RFA with clinical success in terms of hypoglycemic symptoms. RFA procedures were performed during deep sedation, under EUS control with a 19 G needle, an electrode 5-mm in size at a power of 30 W and multiple RFA applications during the same session in order to treat the whole area of the lesions. Immediate relief of symptoms was evident in 2 patients after the first EUS-RFA, while in the third patient a second endoscopic treatment was needed. All 3 patients are symptom-free without need of medications after 24 mo of follow-up with imaging follow-up showing no disease recurrence. A single adverse event of intraprocedural bleeding occurred, which was successfully treated endoscopically.

CONCLUSION

EUS-RFA represents an effective and safe alternative to surgery for the treatment of insulinomas in elderly patients at high surgical risk. However, larger multicenter studies with longer follow-up are needed in order to better assess its safety and clinical success.

Complete Response After Pre-Operative Transcatheter Arterial Chemoembolization for Unresectable Primary Hepatic Neuroendocrine Tumour: A Case Report and Literature Review

Background

Primary hepatic neuroendocrine tumours (PHNET) are extremely rare. Currently, no evidence-based guidelines are available for PHNET treatment, especially for unresectable tumours.

Case Presentation

We present the case of a 43-year-old man who was admitted to our hospital with complaints of backache for more than 1 month. The imaging examination showed a 5.5×5.3 cm lesion in the liver and no extrahepatic lesions, which was confirmed as a grade 2 PHNET by the pathological results and exclusion of non-hepatic origins. A multidisciplinary team (MDT) consultation revealed that the lesion was an unresectable primary hepatic neuroendocrine tumour (uPHNET) but could be potentially treated by conversion surgery. The patient was initially administered four cycles of chemotherapy with temozolomide, 5-fluorouracil, and ondansetron, and was evaluated as stable disease (SD) according to the Response Evaluation Criteria in Solid Tumours version 1.1 (RECIST 1.1). Because of the limited clinical benefit of chemotherapy, the patient subsequently underwent transcatheter arterial chemoembolisation (TACE) treatment, which reduced the tumour size and converted uPHNET to resectable tumours. A complete response (CR) was achieved after surgery, and the patient has been disease-free.

Conclusions

This case was reported by a patient with uPHNET who benefited from the pre-operative TACE, providing a potentially effective management strategy for refractory tumours.

Impact of tumor size and location on endoscopic ultrasound-guided sampling of pancreatic neuroendocrine tumors: A recursive partitioning analysis

BACKGROUND

Current guidelines provide weak recommendations to treat small (<2 cm) non-functional pancreatic neuroendocrine tumors with low Ki-67 proliferation index either by resection or clinical follow-up. However, there is a lack of consensus regarding the minimal size of pNET, which allows EUS-guided biopsy with high enough diagnostic accuracy for stratification.

METHODS

We conducted a retrospective, bicentric analysis of patients who had undergone EUS-guided pNET sampling in two tertiary care Endoscopy Units in Germany and Poland. Using a recursive partitioning of the tree-aided model, we aimed to stratify the probability of successful EUS-guided biopsy of pNET lesions according to their size and location.

RESULTS

In our pNET cohort, successful histological confirmation of a pNET diagnosis was achieved in 59/69 (85.5%) cases at the initial EUS-guided biopsy. In 41 patients with a pNET size less than 18.5 mm, the EUS-guided first biopsy was successful in 90.2%. In 16 of these patients with smaller lesions, EUS-guided sampling was 100% in very small (less than 11 mm) and extremely small lesions (less than 8 mm). The biopsy success rate was 100% in tail lesions in the size range between ≥5.95 and <8.1 mm but only 33.3% independent of the investigator in pancreatic head or body, with an error rate of 11.2% CONCLUSION: Using a recursive partitioning of the tree-aided stratification model, we demonstrate for the first time that in balancing risks and benefits, very small pNETs (<1 cm) in the tail of the pancreas should be sampled under EUS-guidance.

EUS-RFA of the pancreas: where are we and future directions

Surgical resection remains the gold standard for pancreatic cancer, high-risk pancreatic neuroendocrine tumors (PNETs) and pancreatic cystic neoplasms (PCNs). However, a majority of pancreatic cancers are unresectable at the time of diagnosis. In addition, surgical resection of pancreatic lesions can be associated with morbidity and mortality. A less-invasive alternative therapeutic intervention to avoid short term and long-term adverse events is desirable, as is a minimally-invasive palliative therapy for unresectable or recurrent pancreatic cancers. Endoscopic ultrasound guided radiofrequency ablation (EUS-RFA) allows for selective tissue ablation with minimal injury to the surrounding tissue. EUS-RFA of pancreatic tumors has shown high clinical and technical success with acceptable side effects in pancreatic lesions, lymph nodes, and the celiac plexus. This paper will review the pathophysiology, available technology, safety and efficacy, and future directions of EUS-RFA.

A New Preoperative Scoring System for Predicting Aggressiveness of Non-Functioning Pancreatic Neuroendocrine Neoplasms

The management of non-functioning pancreatic neuroendocrine neoplasms (NF-PanNENs) is still controversial. This study aimed to develop a new scoring system for treatment decisions at initial diagnosis based on the identification of the predictive factors for aggressive NF-PanNENs. Seventy-seven patients who had been pathologically diagnosed with NF-PanNENs were enrolled. We retrospectively reviewed 13 variables that could be assessed preoperatively. Univariate and multivariate stepwise logistic regression analyses were performed to identify factors for the aggressiveness of NF-PanNENs, and a scoring system was developed by assigning weighted points proportional to their β regression coefficient. Tumor size > 20 mm on contrast-enhanced computed tomography, tumor non-vascularity, and Ki-67 labeling index ≥5% on endoscopic ultrasound-guided fine-needle aspiration specimens were identified as independent factors for predicting the aggressiveness of NF-PanNENs. The new scoring system, developed using the identified factors, had an excellent discrimination ability, with area under the curve of 0.92 (95% CI, 0.85–0.99), and good calibration (p = 0.72, Hosmer-Lemeshow test). Ten-year overall survival rates in low-risk (0 point), intermediate-risk (1 to 2 points), and high-risk (3 to 4 points) groups were 100%, 90.9%, and 24.3%, respectively. This new scoring system would be useful for treatment decisions and prognostic prediction at initial diagnosis.

Case Report: Insulinoma Co-Existing With Type 2 Diabetes - Advantages and Challenges of Treatment With Endoscopic Ultrasound-Guided Radiofrequency Ablation

The coexistence of insulinoma and type 2 diabetes is rare and the diagnostic process is often challenging. Continuous glucose monitoring system devices, which are more readily available nowadays, provide a useful tool for the diagnosis and evaluation of treatment response. Curative surgery is often the mainstay of treatment for insulinoma. Here, we report a Chinese patient with insulinoma diagnosed simultaneously with type 2 diabetes. His insulinoma was managed with endoscopic ultrasound guided-radiofrequency ablation (EUS-RFA) and the patient achieved complete resolution of hypoglycaemic episodes. The case illustrates that while EUS-RFA is an emerging non-invasive treatment modality for pancreatic lesions, limitations exist especially when histological confirmation is essential.

Endoscopic ultrasound-guided ethanol and radiofrequency ablation of pancreatic insulinomas: a systematic literature review

BACKGROUND

Insulinoma is the most common neuroendocrine neoplasm of the pancreas, characterised by hypoglycaemic symptoms. Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) and ethanol ablation (EUS-EA) are novel methods for treating insulinoma.We aimed to perform a systematic review to assess the efficacy and safety of EUS-guided ablation techniques for pancreatic insulinomas.

METHODS

We systematically searched for articles detailing EUS-guided ablations of insulinomas. We performed a qualitative analysis and summarised data on the efficacy and safety of EUS-RFA and EUS-EA techniques.

RESULTS

In total, we identified 35 case reports and case series describing 75 patients with insulinomas treatment with EUS-guided ablation. Twenty-seven patients were treated with EUS-RFA, 47 patients with EUS-EA, and 1 patient received EUS-EA and EUS-RFA in the same session. In total, 84 insulinomas were ablated (EUS-RFA: 31, EUS-EA: 53). Most insulinomas were in the head of the pancreas (40%). The clinical success rate for EUS-guided ablation techniques was 98.5%. The median glucose level was 1.95 (Q1-Q3: 1.69-2.13) mmol/L before ablation compared to 6.20 (Q1-Q3: 5.30-7.05) mmol/L after treatment. The median insulin and C-peptide levels before and after RFA/EA were 230 (Q1-Q2: 120-257) pmol/L and 41 (Q1-Q2 35-42) pmol/L; 2077 (Q1-Q2 1644-2459) pmol/L and 819 (Q1-Q2 696-1072) pmol/L, respectively. There were eleven adverse events: seven abdominal pain, two mild acute pancreatitis, one necrotising acute pancreatitis and one local hematoma. All patients recovered, and there were no periprocedural deaths.

CONCLUSIONS

EUS-guided ablation of insulinoma seems to be a safe and effective treatment and is an alternative to surgical resection in selected cases.

Evolving Concepts Regarding Radiation Therapy for Pancreatic Cancer

In todays practice most institutions individualize the use of adjuvant, neoadjuvant, and definitive RT based on their interpretation of the available data. This review highlights novel concepts and approaches to the use of RT that should be considered by the surgical oncologist.

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.

Diagnostic and Interventional Role of Endoscopic Ultrasonography for the Management of Pancreatic Neuroendocrine Neoplasms

Pancreatic neuroendocrine neoplasms (PanNENs) are relatively rare, but their incidence has increased significantly in the last decades. Precise diagnosis and prognostic stratification are crucial for proper patient management. Endoscopic ultrasound (EUS) is the modality of choice for diagnosis of solid pancreatic tumors, showing a higher tumor detection rate than other imaging modalities, especially for small size lesions. EUS also serves as a guide for preoperative sampling and other interventions. EUS-tissue acquisition is a safe and highly accurate technique for cyto/histological diagnosis of PanNENs with a well-demonstrated correlation between Ki-67 proliferation index values and tumor grading on EUS and surgical specimens according to the WHO 2017 classification. Furthermore, the possibility of a preoperative EUS-guided fine needle tattooing or fiducial markers placement may help the surgeon to locate small and deep tumors, thus avoiding formal pancreatic resections in favor of parenchymal-sparing surgery. Finally, locoregional ablative treatments using either ethanol injection or radiofrequency ablation have been proposed in recent studies with promising results in order to control symptoms or reduce tumor burden in selected patients unfit for surgery with functioning or non-functioning PanNENs. This article review highlights the current role of EUS in PanNENs management, focusing on the present and future applications of EUS-guided interventions.

Advances in The Diagnosis and Treatment of Achalasia of The Cardia: a Review

Idiopathic achalasia is an esophageal motor disorder characterized by the loss of the lower esophageal sphincter ganglion, resulting in impaired lower esophageal relaxation and absence of esophageal peristalsis. Patients commonly present with progressive dysphagia accompanied by reflux, heartburn, retrosternal pain, and severe weight loss. Diagnosis is primarily based on the patient's chief complaints, barium esophagography, and the most recent high-resolution manometry. Endoscopic assessment and endoscopic ultrasonography also have significant value with regard to the exclusion of esophageal anatomical lesions, neoplastic diseases, and pseudoachalasia. However, as most patients with achalasia demonstrate a gradual onset, early diagnosis is difficult. Currently, treatment of idiopathic achalasia, including pneumatic dilation, stent placement, and surgical myotomy, is aimed at reducing lower esophageal sphincter pressure and relieving the symptoms of dysphagia. Peroral endoscopic myotomy has gradually become the mainstream treatment because it causes less trauma and has a rapid recovery rate. This article reviews the main methods of diagnosis and treatment of achalasia, with an emphasis on the potential of peroral endoscopic myotomy and the advancements of immunotherapy for achalasia.

Case Report: Pancreatic Neuroendocrine Tumor With Liver Metastasis and Portal Vein Thrombosis

INTRODUCTION

Pancreatic neuroendocrine neoplasms (PNENs) are rare pancreatic tumors originating from pancreatic neuroendocrine cells. There is no consensus on the treatment for PNENs with unresectable liver metastases. Transcatheter arterial chemoembolization (TACE) is the preferred treatment for unresectable primary liver cancer. But the efficacy of TACE and anticoagulation in PNENs with unresectable liver metastases and portal vein thrombosis has never been reported.

METHODS AND RESULTS

We present the case of a 50-year-old male patient with hepatitis C who was found to have a single liver mass during a regular physical examination in 2016. The liver mass was surgically removed. Postoperative pathology suggested a neuroendocrine tumor of the liver, and it was suggested to look for the primary tumor. The patient was followed up until 2020, and the primary pancreatic tumor was found, along with multiple liver metastases and portal vein thrombosis. After transcatheter arterial embolization, anticoagulation, and endocrine therapy, the patient's tumor load was relieved, and the portal vein was recanalized.

CONCLUSION

The article reports the disease course in a case of a functional pancreatic neuroendocrine tumor with liver metastasis and portal vein thrombosis and reviews previous literature. To our knowledge, we reported for the first time the efficacy of TACE and anticoagulation in PNENs with unresectable liver metastases and portal vein thrombosis.

Endoscopic ultrasound-guided radiofrequency ablation of pancreatic neuroendocrine tumors: a systematic review of the literature

Background and study aims  Surgery is the mainstay therapy for pancreatic neuroendocrine tumors (P-NETs), but it is associated with significant adverse events (AEs). In recent years, endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) has been described for treating P-NETs. We performed a systematic literature review aimed at exploring the feasibility, effectiveness, and safety of EUS-RFA in treatment of P-NETs. Methods  The literature review was performed in PubMed/MEDLINE, EMBASE, and SCOPUS to identify all case reports of EUS-RFA for treatment of P-NETs. Results  Sixyt-one patients (males 49.2 %, mean age 64.5 years) and 73 tumors (mean size 16 mm, insulinomas 30.1 %) treated with EUS-RFA were included from 12 studies. The overall effectiveness of EUS-RFA was 96 % (75 % - 100 %) without differences between functional vs. non-functional P-NETs ( P  = 0.3) and without relevant issues about safety (mild AEs 13.7 %). While tumor location was not predictive for incomplete/non-response to EUS-RFA, greater tumor dimensions predicted treatment failure (21.8 ± 4.71 mm in the non-response group vs 15.07 ± 7.34 mm in the response group, P  = 0.048). At ROC analysis, a P-NET size cut-off value ≤18 mm predicted response to treatment, with a sensitivity of 80 % (95 % CI 28.4 % - 99.5 %), a specificity of 78.6 % (95 % CI 63.2 % - 89.7 %), a positive predictive value of 97.1 % (95 % CI 84.7 % - 99.9 %) and a negative predictive value of 30.8 % (95 % CI 9.1 % - 61.4 %), with an area under the curve of 0.81 (95 % CI 0.67 - 0.95). Conclusions  EUS-RFA is safe and effective for treating P-NETs. It may be reasonable to consider EUS-RFA for small P-NETs, irrespective of the functional status.

Endoscopic ultrasound-guided radiofrequency ablation of pancreatic neuroendocrine tumors: a case series

Background and study aims  Surgery is the considered the therapeutic cornerstone for pancreatic neuroendocrine tumors (P-NETs), although burdened by high risk of significant adverse events. Recently, endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) has been described for P-NETs. We aimed to evaluate the effectiveness and safety of EUS-RFA for treatment of P-NETs. Patients and methods  We prospectively included all consecutive patients with P-NET ≤ 20 mm who were treated with EUS-RFA and were followed-up for at least 12 months. Results  Ten patients (5 males, mean age 78.6 years, mean body mass index 28.2) with 11 P-NETs (mean size 14.5 mm; range 9 - 20 mm) localized in the pancreatic head (3 lesions), pancreatic body (5 lesions), and tail (3 lesions) underwent complete EUS ablation with one session of RFA. Complete ablation of P-NET was reached using a single-session RFA with a mean of 2.3 treatment applications per session. At both 6 - and 12-months computed tomography scans, all the patients had complete disappearance of lesions with radiological normalization. Regarding safety, only two cases of mild abdominal pain were recorded in two subjects with pancreatic head lesion, which were effectively treated with analgesics. The mean duration of hospital stay was 4 days (range 3 - 7 days). Conclusions  EUS-RFA is effective and safe in treating P-NETs. It may be considered an effective therapeutic option in the treatment of small P-NETs independently from their functional status.

Transcriptional Profiling Reveals the Regulatory Role of DNER in Promoting Pancreatic Neuroendocrine Neoplasms

Wnt/β-catenin and NOTCH signaling contribute to the pathogenesis and growth of (PanNENs). The wnt and Notch signaling pathways form an integrated signaling device termed "wntch" and regulate stochastic cell fate decisions, suggesting the essentiality of Wnt/Notch interactions in disease progression. However, the function of Wnt/Notch interactions in PanNENs is unclear. We analyzed RNA sequencing (RNA-seq) data to identify differentially expressed lncRNAs, mRNAs and pathways according to enriched Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways associated with PanNENs. RNA-seq analysis revealed that the levels of the lncRNA XLOC_221242 and the mRNA encoding Delta/Notch-like epidermal growth factor (EGF)-related receptor (DNER) were significantly increased in tumor tissues compared with normal tissues (n = 3). Protein-protein interaction (PPI) prediction combined with transcriptional profiling data analysis revealed that DNER expression levels were positively correlated with those of DNA-binding factor (RBPJ), S phase kinase-associated protein 1 (Skp1), CTNNB1 and Cadherin-2 (CDH2), which promote PanNEN tumorigenesis and progression. These results were consistent with those of immunohistochemical analysis of DNER, RBPJ, SKP1, CTNNB1, and CDH2 expression (n = 15). These findings provide compelling clinical and molecular evidence supporting the conclusion that DNER and the related RBPJ, SKP1, CTNNB1, and CDH2 signaling contribute to PanNEN tumorigenesis and progression by activating wnt/Notch interactions.

Efficacy of EUS-RFA in pancreatic tumors: Is it ready for prime time? A systematic review and meta-analysis

Background and study aims  Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) can be used in patients with unresectable pancreatic ductal adenocarcinoma (PDAC). We performed a systematic review and meta-analysis to evaluate the efficacy of EUS-RFA in treatment of locally advanced unresectable PDAC and other pancreatic tumors. Patients and methods  A comprehensive search was done of multiple electronic databases and conference proceedings including PubMed, EMBASE, Web of Science databases, Google Scholar and manual search of references (from inception through May 2019) to identify the studies reporting use of EUS-RFA for pancreatic lesions. The primary outcome was to evaluate technical and clinical success of the procedure. The secondary outcome was to study overall adverse events (AEs). Results  Thirteen studies reporting 165 EUS-RFA procedures on 134 patients were included. Of 134 patients, 27.94 % (38) had unresectable locally advanced PDAC, 40 % (53) had PNETs, 3 % (4) had metastasis to the pancreas and 30 % (41) had other lesions. The pooled technical success rate calculated out of the total number of procedures was 100 % (95 % CI [99.18 - 100], I2 = 0 %). The pooled clinical success rate calculated out of the total number of patients was 91.58 % (95 % CI [82.5 - 98.08], I2 = 21.5 %). The pooled overall AE rates were 14.67 % (95 % CI [4.77 - 27.46], I2 = 56.19 %) out of which abdominal pain was the most common with 9.82 % (95 % CI [3.34 - 18.24], I2 = 23.76 %). Low to moderate heterogeneity was noted. Conclusion  EUS-RFA has high technical (100 %) and clinical success (91.5 %) rates. Further multicenter trials are needed to further validate our findings.

Endosonography-guided Radiofrequency Ablation in Pancreatic Diseases: Time to Fill the Gap Between Evidence and Enthusiasm

Over the past 20 years, endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) has generated interest as a novel minimally invasive tool in the multimodal treatment of pancreatic malignant and premalignant lesions. However, although optimization of probes and settings has made EUS-RFA relatively safe, questions on the ideal positioning of this treatment in a multimodal strategy remain unanswered. This review will summarize the technical aspects of EUS-RFA and available clinical experiences for each pancreatic indication (pancreatic cancer, neuroendocrine neoplasms, cystic lesions, and celiac ganglia neurolysis). Established indications will be discussed along those requiring additional clinical data or even proof-of-concept studies. A dedicated session will further discuss evidence expected to emerge from ongoing registered trials, together with issues that must be addressed in future research, including the possible combination with immunotherapy, and the personalization of this treatment on the basis of genetic profiling. Despite the great clinical enthusiasm and scientific fervor, while evidence-based answers are produced, EUS-RFA must be centralized in high-volume centers of recognized expertise, where multidisciplinary discussions of indications and actively recruiting research protocols are available.