Feasibility and safety of EUS-guided cryothermal ablation in patients with locally advanced pancreatic cancer

Assessing EUS-guided radiofrequency ablation in unresectable pancreatic ductal adenocarcinoma: a single-center historic cohort study

BACKGROUND AND AIMS

EUS-guided radiofrequency ablation (EUS-RFA) has emerged as an alternative for the local treatment of unresectable pancreatic ductal adenocarcinoma (PDAC). We assessed the feasibility and safety of EUS-RFA in patients with unresectable PDAC.

METHODS

This study followed an historic cohort compounded by locally advanced (LA-) and metastatic (m)PDAC-naïve patients who underwent EUS-RFA between October 2019 and March 2022. EUS-RFA was performed with a 19-gauge needle electrode with a 10-mm active tip for energy delivery. Study primary endpoints were feasibility, safety, and clinical follow-up, whereas secondary endpoints were performance status (PS), local control, and overall survival (OS).

RESULTS

Twenty-six patients were selected: 15 with locally advanced pancreatic duct adenocarcinoma (LA-PDAC) and 11 with metastatic pancreatic duct adenocarcinoma (mPDAC). Technical success was achieved in all patients with no major adverse events. Six months after EUS-RFA, OS was seen in 11 of 26 patients (42.3%), with significant PS improvement (P = .03). Local control was achieved, with tumor reduction from 39.5 mm to 26 mm (P = .04). A post-treatment hypodense necrotic area was observed at the 6-month follow-up in 11 of 11 patients who were still alive. Metastatic disease was a significant factor for worsening OS (hazard ratio, 5.021; 95% confidence interval, 1.589-15.87; P = .004).

CONCLUSIONS

EUS-RFA for the treatment of pancreatic adenocarcinoma is a minimally invasive and safe technique that may have an important role as targeted therapy for local treatment of unresectable cases and as an alternative for poor surgical candidates. Also, RFA may play a role in downstaging cancer with a potential increase in OS in nonmetastatic cases. Large prospective cohorts are required to evaluate this technique in clinical practice.

Perioperative outcomes and long-term survival of cryosurgery on unresectable pancreatic cancer: a systematic review and meta-analysis

BACKGROUND

Pancreatic cancer (PC) continues to rank as one of the deadliest forms of cancer, with the majority of patients being diagnosed with unresectable disease. The implementation of cryoablation-based comprehensive treatment is expected to lead to a reduction in tumour size and potentially achieve complete resection. However, the availability of systematic and evidence-based treatment guidelines for cryoablation in pancreatic cancer is currently limited.

MATERIALS AND METHODS

A computerized search was conducted in the Medline, Embase, Cochrane Library databases, and Clinicaltrials to retrieve studies published from August 1987 to June 2023. The perioperative outcomes and long-term survival of patients with locally advanced pancreatic cancer (LAPC) or metastatic pancreatic cancer (mPC) who underwent cryosurgery were systematically collected. Heterogeneity was assessed using Cochran's Q test, and a funnel plot was implemented to evaluate publication bias. Data were pooled and analyzed using Stata 14.0 software. The Newcastle-Ottawa Quality Assessment Form tool was employed for quality evaluation.

RESULTS

Nine studies, including 368 patients, were identified. The pooled overall incidence rate was 4% (95% CI: 0-14%; I²=54.06%) for acute pancreatitis, 0% (95% CI: 0-0%; I²=0.0%) for delayed gastric emptying, 0% (95% CI: 0-1%; I²=0.0%) for postoperative pancreatic fistula (POPF) or bile leakage, 2% (95% CI: 0-5%; I²=0.0%) for bleeding, and 4% (95% CI: 0-12%; I²=70.46%) for fever. The subgroup analysis revealed that the percutaneous treatment group had a lower incidence of complications compared to laparotomy but had higher incidences of POPF, bleeding, and pancreatitis than the intraoperative group. Median overall survival (OS) varied from 5 to 16.2 months. The median survival rates at 6, 12, 24, and 36 months for patients who underwent cryosurgery were as follows: 94.9%, 64.8% (range: 4.8-63.1%), 22.80%, and 9.5%, respectively.

CONCLUSION

With the advancements in cryoablation and anti-tumour therapy, cryoablation has emerged as a promising treatment modality for patients with unresectable pancreatic cancer. According to existing literature, the combination of cryoablation with radioactive particle implantation or immunotherapy has demonstrated considerable efficacy and safety. However, while the majority of included data is derived from retrospective studies, it is imperative to conduct larger sample sizes or prospective trials for further validation.

Endoscopic Ultrasound-Guided Ablation of Premalignant Pancreatic Cysts and Pancreatic Cancer

Pancreatic cancer is on the rise and expected to become the second leading cause of cancer-related death by 2030. Up to a one-fifth of pancreatic cancers may arise from mucinous pancreatic cysts, which are frequently present in the general population. Currently, surgical resection is the only curative approach for pancreatic cancer and its cystic precursors. However, only a dismal proportion of patients are eligible for surgery. Therefore, novel treatment approaches to treat pancreatic cancer and precancerous pancreatic cysts are needed. Endoscopic ultrasound (EUS)-guided ablation is an emerging minimally invasive method to treat pancreatic cancer and premalignant pancreatic cysts. Different ablative modalities have been used including alcohol, chemotherapy agents, and radiofrequency ablation. Cumulative data over the past two decades have shown that endoscopic ablation of mucinous pancreatic cysts can lead to cyst resolution in a significant proportion of the treated cysts. Furthermore, novel data are emerging about the ability to endoscopically ablate early and locally advanced pancreatic cancer. In this review, we aim to summarize the available data on the efficacy and safety of the different EUS-ablation modalities for the management of premalignant pancreatic cysts and pancreatic cancer.

EUS-guided interventional therapies for pancreatic diseases

Endoscopic ultrasound (EUS) is an integrated diagnostic technique merging endoscope and ultrasound to examine the digestive system. EUS has emerged as a primary diagnostic method for pancreatic diseases due to its distinctive benefits. Over the past four decades, EUS has undergone a transformation, shifting its role from primarily diagnostic to increasingly therapeutic. Additionally, in recent years, EUS has emerged as an increasingly prominent adjunctive or alternative approach to conventional surgical interventions. This review provides a comprehensive analysis of current technological approaches in the treatment of pancreatic diseases. The dynamic interplay with diverse therapeutic approaches has reinvigorated EUS and shaped its trajectory in the management of pancreatic diseases.

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.

Advancements in Microwave Ablation Techniques for Managing Pancreatic Lesions

Thermal ablation, including microwave ablation, has become increasingly important in the management of many solid tumors, including primary and metastatic tumors of the liver, kidney, and lung. However, its adoption to treat pancreatic lesions has been slowed due to concerns about potential adverse events. The success of radiofrequency ablation (RFA) in inoperable pancreatic cancers paved the way for its use in pancreatic neuroendocrine tumors and pancreatic cystic neoplasms (PCLs). In the last decade, other thermal ablation techniques, like microwave ablation, have emerged as alternatives to RFA. Microwaves, with frequencies ranging from 900 to 2450 MHz, generate heat by rapidly oscillating water molecules. Microwave ablation's advantage lies in its ability to achieve higher intra-lesion temperatures and uniform heating compared with RFA. Microwave ablation's application in pancreatic cancer and pancreatic neuroendocrine tumors has demonstrated promise with similar technical success to RFA. Yet, concern for peri-procedure complications, as well as a dearth of studies comparing RFA and microwave ablation, emphasize the need for further research. No studies have evaluated microwave ablation in PCLs. We herein review thermal ablation's potential to treat pancreatic lesions.

Immunomodulatory Effects of Endoscopic Ultrasound-Guided Thermal Ablation in Patients with Pancreatic Ductal Adenocarcinoma

Immunological consequences of endoscopic ultrasound (EUS)-local thermal ablation (LTA) for pancreatic ductal adenocarcinoma (PDAC) have not been extensively assessed. We aimed to explore EUS-LTA effects on the systemic immune response in PDAC. Peripheral blood was collected from 10 treatment-naïve patients with borderline resectable and locally advanced PDAC, randomly allocated to Nab-paclitaxel plus Gemcitabine chemotherapy (CT-arm, n = 5) or EUS-LTA with HybridTherm Probe plus CT (HTP + CT-arm, n = 5). Twenty healthy donors were included as controls. Flow-cytometry and multiplex assays were used to profile immune cell subsets and measure serum cytokines/chemokines, respectively. At baseline, PDAC patients showed increased circulating monocytes and lower circulating lymphocytes and CD19+ B cells counts compared to healthy controls. After 4 months, CT induced decrease of B regulatory cells, CD4+ cytotoxic T cells and IL-1β. The addition of EUS-HTP to CT selectively decreased the serum levels of APRIL/TNFSF13 as well as T regulatory cells, total, classic and inflammatory monocytes. Serum levels of APRIL/TNFSF13 and total, classic and inflammatory monocytes counts at baseline were associated with worse overall survival. EUS-HTP has the potential to selectively impact on immune cells and cytokines associated with poor outcomes in PDAC.

Role of Therapeutic Endoscopic Ultrasound in Management of Pancreatic Cancer: An Endoscopic Oncologist Perspective

Pancreatic cancer is a highly lethal disease with an aggressive clinical course. Patients with pancreatic cancer are usually asymptomatic until significant progression of their disease. Additionally, there are no effective screening guidelines for pancreatic cancer in the general population. This leads to a delay in diagnosis and treatment, resulting in poor clinical outcomes and low survival rates. Endoscopic Ultrasound (EUS) is an indispensable tool for the diagnosis and staging of pancreatic cancer. In the modern era, with exponential advancements in technology and device innovation, EUS is also being increasingly used in a variety of therapeutic interventions. In the context of pancreatic cancer where therapies are limited due to the advanced stage of the disease at diagnosis, EUS-guided interventions offer new and innovative options. Moreover, due to their minimally invasive nature and ability to provide real-time images for tumor localization and therapy, they are associated with fewer complication rates compared to conventional open and laparoscopic approaches. In this article, we detail the most current and important therapeutic applications of EUS for pancreatic cancer, namely EUS-guided Fine Needle Injections, EUS-guided Radiotherapy, and EUS-guided Ablations. Furthermore, we also discuss the feasibility and safety profile of each intervention in patients with pancreatic cancer to provide gastrointestinal medical oncologists, radiation and surgical oncologists, and therapeutic endoscopists with valuable information to facilitate patient discussions and aid in the complex decision-making process.

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.

New Perspectives on Endoscopic Management of Liver and Pancreatic Cancer

Liver and pancreatic cancers are major health issues which represent a clinical and economic burden worldwide [...].

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.

Endoscopic ultrasound guided radiofrequency ablation for pancreatic tumors: A critical review focusing on safety, efficacy and controversies

The role of endoscopic ultrasound (EUS) in the last two decades has shifted from a diagnostic tool to an important therapeutic tool treating mainly pancreato-biliary disorders. In recent years, its applications for treating pancreatic diseases have broadened, including the implementation of radiofrequency ablation (RFA), which has been traditionally used for treating solid tumors. In this critical in-depth review, we summarized all the papers throughout the literature regarding EUS-RFA for pancreatic neuroendocrine neoplasms, adenocarcinoma, and pancreatic cystic lesions. Overall, for pancreatic neuroendocrine neoplasms we identified 16 papers that reported 96 patients who underwent EUS-RFA, with acceptable adverse events that were rated mild to moderate and a high complete radiological resolution rate of 90%. For pancreatic adenocarcinoma, we identified 8 papers with 121 patients. Adverse events occurred in 13% of patients, mostly rated mild. However, no clear survival benefit was demonstrated. For pancreatic cystic lesions, we identified 4 papers with 38 patients. The adverse events were mostly mild and occurred in 9.1% of patients, and complete or partial radiological resolution of the cysts was reported in 36.8%. Notably, the procedure was technically feasible for most of the patients. Nevertheless, a long road remains before this technique finds its definite place in guidelines due to several controversies. EUS-RFA for pancreatic tumors seems to be safe and effective, especially for pancreatic neuroendocrine neoplasms, but multicenter prospective trials are needed to consider this treatment as a gold standard.

Current landscape of therapeutic EUS: Changing paradigms in gastroenterology practice

Therapeutic EUS has witnessed exponential growth in the last decade, but it has been considered investigational until recently. An increasing body of good-quality evidence is now demonstrating clear advantages over established alternatives, adding therapeutic EUS to management algorithms of complex hepato-pancreato-biliary (HPB) and gastrointestinal (GI) conditions. In this review, the available evidence and clinical role of therapeutic EUS in established and evolving applications will be discussed. A Graphical Summary for each scenario will provide (1) technical steps, (2) anatomical sketch, (3) best-supporting evidence, and (4) role in changing current and future GI practice. Therapeutic EUS has accepted well-established applications such as drainage of symptomatic peripancreatic fluid collections, biliary drainage in failed endoscopic retrograde cholangiopancreatography, and treatment of acute cholecystitis in unfit-for-surgery patients. In addition, good-quality evidence on several emerging indications (e.g., treatment of gastric outlet obstruction, local ablation of pancreatic solid lesions, etc.) is promising. Specific emphasis will be given to how these technical innovations have changed management paradigms and algorithms and expanded the possibilities of gastroenterologists to provide therapeutic solutions to old and emerging clinical needs. Therapeutic EUS is cementing its role in everyday practice, radically changing the treatment of different HPB diseases and other conditions (e.g., GI obstruction). The development of dedicated accessories and increased training opportunities will expand the ability of gastroenterologists to deliver highly effective yet minimally invasive therapies, potentially translating into a better quality of life, especially for oncological and fragile patients.

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].

EUS-guided ablation with the HybridTherm Probe as second-line treatment in patients with locally advanced pancreatic ductal adenocarcinoma: A case-control study

Background and Objectives

Data on the clinical efficacy of EUS-guided ablation using the HybridTherm-Probe (EUS-HTP) in locally advanced pancreatic ductal adenocarcinoma (LA-PDAC) are lacking. The aim of the study was to assess the impact of EUS-HTP added to chemotherapy (CT) on overall survival (OS) and progression-free survival (PFS) of LA-PDAC patients with local disease progression (DP) after first-line therapy, compared to CT alone in controls.

Methods

LA-PDAC cases, prospectively treated by EUS-HTP, were retrospectively compared to matched controls (1:2) receiving standard treatment. Study endpoints were the OS and PFS from local DP after first-line therapy, compared through log-rank test calculating hazard ratios and differences in restricted mean OS/PFS time (RMOST/RMPFST) within prespecified time points (4, 6, and 12 months).

Results

Thirteen cases and 26 controls were included. Clinical, tumor, and therapy features before and after first-line therapy were case-control balanced. The median OS and PFS were not significantly improved in cases over controls (months: 7 vs. 5 and 5 vs. 3, respectively). At 4 and 6 months, the RMPFST difference was in favor of cases (P = 0.0001 and P = 0.003, respectively). In cases and controls not candidate to further CT (N = 5 and N = 9), the median OS and PFS were not significantly improved in cases over controls (months: 6 vs. 3 and 4 vs. 2, respectively), but the RMPFST difference was in favor of cases at 4 months (P = 0.002).

Conclusions

In locally progressive PDAC patients experiencing failure of first-line therapy, EUS-HTP achieves a significantly better RMPFST up to 6 months compared to standard treatment, although without a significant impact on OS.

Endoscopic Management of Pancreatobiliary Malignancies

Pancreatobiliary malignancies have poor prognosis, and many patients are inoperable at the time of diagnosis. When surgical resection is impossible, systemic chemotherapy or radiotherapy is traditionally conducted with trial of immunotherapy or gene therapy lately. With the rapid development of endoscopic instruments and accessories in recent years, not only endoscopic early detection, characterization, and staging but also endoscopic palliative management of the pancreatobiliary malignancies is expanding the horizons. Endoscopic management is often preferred due to similar efficacy to surgical management with less morbidity. Here, we review the methodology and treatment outcome of various endoscopic management strategies in pancreatobiliary malignancies including endoscopic complication management, local palliative therapy, endoscopy-assisted therapy, and pain control utilizing endoscopic retrograde cholangiopancreatography or endoscopic ultrasound.

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.

An update on EUS-guided ablative techniques for pancreatic cystic lesions

Pancreatic cystic lesions (PCLs) are increasingly being recognized due to improvements and widespread use of cross-sectional imaging. With an estimated prevalence of 15% in general population, incidentally discovered PCLs represent a dilemma in management. While pancreatectomies offer a chance of cure, the morbidity is considerable in patients with high surgical risks. More recently, EUS-guided approaches for cyst ablation are being offered in clinical trials for the management of PCLs. EUS-chemoablation studies have progressed from first investigating safety and efficacy of EUS-guided alcohol lavage to single-agent paclitaxel ablation. Recent studies have shown that alcohol lavage may not be required, and long-term resolution can be achieved by chemoablation alone. EUS-guided lauromacrogol ablation and EUS-guided radiofrequency ablation (RFA) are new techniques that have shown promising results in a few small studies. Overall, the current literature suggests that EUS-guided paclitaxel ablation has better cyst resolution rates compared to other existing minimally invasive techniques including ethanol injection, lauromacrogol ablation, or RFA. This article will review EUS-guided PCL ablation approaches and future directions the field is headed into.

Endoscopic ultrasound-guided ablation of solid pancreatic lesions: A systematic review of early outcomes with pooled analysis

BACKGROUND

Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) is emerging as a complementary therapeutic approach for pancreatic solid masses. However, results of published data are difficult to interpret because of a retrospective design and small sample size.

AIM

To systematically review data on EUS-RFA for solid lesions and to pool the results of the different experiences in order to provide more consistent evidence in terms of safety and efficacy.

METHODS

A comprehensive systematic literature search on the main databases was performed to identify articles in which patients with pancreatic solid lesions underwent EUS-RFA. The primary outcomes were procedure-related adverse events (AEs) and mortality. Secondary outcomes were the technical success rate and the effects on primary tumor growth. Statistical analyses were performed using Stata version 14.0.

RESULTS

In total, 14 studies were included, with 120 patients undergoing 153 ablations of 129 solid pancreatic lesions. The STARmed technology was used in seven studies, the Habib system in six studies, and the HybridTherm probe in one study. The pooled technical success rate was 99.0% (I²: 25.82%). The pooled overall AE rate was 8.0% (I²: 11.46%). Excluding mild AEs, the pooled rates of serious AEs was 1.0% (I²: 0%). No mortality related to the procedure was reported.

CONCLUSION

The present pooled analysis confirms the safety and feasibility of EUS-RFA.

Endoscopic ultrasound role in pancreatic adenocarcinoma treatment: A review focusing on technical success, safety and efficacy

The impressive technological advances in recent years have rapidly translated into the shift of endoscopic ultrasound (EUS) from diagnostic modality into an interventional and therapeutic tool. Despite the great advance in its diagnosis, the majority of pancreatic adenocarcinoma cases are inoperable when diagnosed, thus demanding alternative optional therapies. EUS has emerged as an easy, minimally invasive modality targeting this carcinoma with different interventions that have been reported recently. In this review we summarize the evolving role of interventional therapeutic EUS in pancreatic adenocarcinoma management.

Role of therapeutic endoscopic ultrasound in gastrointestinal malignancy- current evidence and future directions

Endoscopic ultrasound (EUS) has come a long way from a mere diagnostic tool to an advanced therapeutic modality. With the advent of better technologies and accessories, EUS has found ground in the management of gastrointestinal (GI) malignancies, not only for diagnosis but also for therapeutic purposes. EUS can tackle a host of conditions, including hepato-pancreatico-biliary malignancies. Advances and experience in various EUS-guided biliary drainage techniques have enabled the endosonologist to tackle biliary obstruction when conventional techniques of endoscopic retrograde cholangiopancreatography (ERCP) and/or percutaneous transhepatic biliary drainage (PTBD) fails. More and more emerging data not only establishes the safety of EUS-BD but also demonstrates superior efficacy over PTBD and sometimes even ERCP. Malignant gastric outlet obstruction can now be safely managed with EUS-guided gastroenterostomy. Starting from pain management in malignant tumors through celiac plexus neurolysis to various tumor ablative therapies, EUS has forged ahead over percutaneous treatment or surgical options in the management of GI malignancies. Additional data is now coming up on the prospects of EUS-guided immunotherapy and biological therapy for tumor management. The future of EUS therapeutics in the field of GI malignancies is bright. With increasing evidence, this modality becoming a key player in management of a host of complex clinical conditions arising out of GI malignancies is in the offing. This review focuses on elucidating the role of therapeutic EUS in the management of GI malignancies, a synopsis of various techniques, data on its safety and efficacy as well as future advancements in this domain.

Can local ablative techniques replace surgery for locally advanced pancreatic cancer?

In the treatment of pancreatic ductal adenocarcinoma (PDAC) the best chance at long term survival or cure has to date always included the complete surgical removal of the tumor. However, locally advanced pancreatic cancer (LAPC), about 25% of all newly diagnosed PDAC, is defined by its primary technical unresectability due to infiltration of visceral arteries and absence of metastasis. Induction therapies, especially FOLFIRINOX treatment, together with technical surgical advancement have increased the numbers for conversion to secondary resectability. Recent data on resections after induction therapy show promising, almost doubled survival compared to palliative treatment. Yet, around 70% of LAPC remain unresectable after induction therapy, often due to persistent local invasion. As locally ablative techniques are becoming more widely available this review examines their possible applicability to substitute for surgery in these cases which we propose to group under the new term "Inconvertible LAPC". The need for defining this novel subgroup who might benefit from ablative treatment is based on the findings in our review that high-level evidence on ablative techniques for PDAC is largely lacking and the latest effective, harmonized treatment guidelines for LAPC are not often incorporated in these studies. The "inconvertible LAPC" label requires persistent unresectability after staging and induction therapy of LAPC according to current guidelines followed by liberal indication for aggressive surgical exploration at a center equipped for extended pancreatic resections. Ideally, this specification of a new, distinct patient group will also put it in the spotlight more, hopefully prompt more trials designed to generate robust evidence and optimize transferability of study results.

Efficacy of Endoscopic Ultrasound-Guided Ablation with the HybridTherm Probe in Locally Advanced or Borderline Resectable Pancreatic Cancer: A Phase II Randomized Controlled Trial

Endoscopic ultrasound-ablation with HybridTherm-Probe (EUS-HTP) significantly reduces tumour volume (TV) in locally-advanced pancreatic ductal adenocarcinoma (LA-PDAC). We aimed at investigating the clinical efficacy of EUS-HTP plus chemotherapy versus chemotherapy (HTP-CT and CT arms) in LA- and borderline-resectable (BR) PDAC, with 6-months progression-free survival (6-PFS) rate as primary endpoint. In a phase-II randomized-controlled-trial, 33 LA/BR-PDAC patients per-arm were planned to verify 20% improved 6-PFS rate. Radiological response (Choi criteria), TV and serum CA19.9 were assessed up to 6-months. Seventeen and 20 LA/BR-PDAC patients were randomized to HTP-CT or CT. Baseline and CT-related features were balanced. At 6-months, 6-PFS rate was 41.2% and 30% in HTP-CT and CT arms (p = 0.48), respectively. A decrease ≥50% of serum CA19.9 was achieved in 75% and 64.3% of HTP-CT and CT patients (p = 0.53), respectively. TV reduced up to 6-months in 64.3% and 47.1% of HTP-CT and CT patients (p = 0.35), respectively. Resection rate, PFS-time and overall survival (OS-time) were similar. HTP-CT achieves a non-significant 11.2%, 10.7% and 17.2% improved 6-PFS, CA19.9 decrease ≥50% and TV reduction rates over CT, without any impact on resection rate, PFS-time and OS-time. As the study was underpowered, these results suggest further investigation of EUS-local ablation in selected patients with localized disease after induction CT.

A Multicenter Randomized Controlled Prospective Study to Assess Efficacy of Laparoscopic Electrochemotherapy in the Treatment of Locally Advanced Pancreatic Cancer

Background: Eighty percent of patients with pancreatic adenocarcinoma present a locally advanced or metastatic disease at diagnosis and are not eligible for surgery if not with palliative intent. In cases of locally advanced disease (LAPC), the combination of chemo and radiotherapy is the only therapeutic option and correlates with a median survival of 15 months (10 months without treatment), with partial remission of disease in 50% of cases. The feasibility and safety of Electrochemotherapy (ECT) have been demonstrated in the treatment of deep tumors. Aim: The aim of the study is to evaluate the efficacy of electrochemotherapy (ECT) followed by conventional systemic treatment compared to the only conventional systemic treatment in LAPC in terms of objective response and overall survival. Patients and Methods: This study is a phase IIb prospective multicenter randomized controlled trial with two arms. The study will include 90 patients: 45 in the control group and 45 in the experimental group. Patients with LAPC in the control arm will receive conventional chemotherapy (FOLFOXIRI). Patients with LAPC in the experimental arm will be subjected to Electrochemotherapy and subsequently to FOLFOXIRI. The objective response at 30, 90, and 180 days from treatment will be based on the computed tomography (CT), magnetic resonance (MR), and positron emission tomography/CT response (PET/CT). The objective long-term treatment response will be evaluated with the modified response evaluation criteria in solid tumors (m-RECIST) criteria, which will take into account the difference in vascularization, determined by the images obtained by CT and MR of the tumor treated before and after ECT. Conclusions: Not resectable liver metastasis, pancreatic tumors, and locally advanced renal carcinomas can be treated with laparoscopic electrodes. ECT could represent an effective therapeutic option for patients not eligible for surgery susceptible to be managed only with palliative therapies.

Laparoscopic ultrasonography-guided cryoablation of locally advanced pancreatic cancer: a preliminary report

OBJECTIVE

To evaluate safety and feasibility of laparoscopic ultrasonography (LUS)-guided cryoablation of locally advanced pancreatic cancer (LAPC).

PATIENTS AND METHODS

From April 2018 to December 2018, ten patients (five women, five men; mean age 58.2 ± 9.4 years) with LAPC underwent the operation. LUS was used to guide the cryoablation. Computed tomography (CT) imaging, biochemical analysis and pain score analysis by numeric rating scale (NRS) were used to assess treatment outcomes at 1 week and 3 months after the operation.

RESULTS

Cryoablation was performed by the operation in all cases. Seven patients received complete ablation and the success rate of operation was 70%. Two cryoablation cycles and an average of 1.4 ± 0.5 cryoprobes were used. The average freezing time and operation time were 23.8 ± 1.0 and 110.5 ± 24.7 min, respectively. The mean blood loss was 52.0 ± 16.6 ml. No major complications were observed after the operation. The mean maximum tumor diameter determined by CT decreased from 4.9 ± 0.7 cm before the operation to 4.7 ± 1.0 cm at 1 week and 4.6 ± 1.3 cm at 3 months, with P values of 0.53 and 0.51 (relative to the preoperative values), respectively. Postoperative CT imaging results suggested tumor necrosis in cryoablation-treated areas. The mean CA19-9 levels decreased from 347.5 ± 345.7 U/mL before operation to 190.4 ± 153.8 U/mL at 1 week and 182.7 ± 165.6 U/mL at 3 months, with P values of 0.15 and 0.14 (relative to the preoperative values), respectively. The average pain scores declined from 6.9 ± 1.1 before operation to 1.3 ± 1.2 at 1 week and 2.0 ± 0.8 at 3 months, with both P values of < 0.01 (relative to the preoperative values).

CONCLUSION

This preliminary study suggested that LUS-assisted cryoablation was a safe and feasible treatment for LAPC.

EUS-guided ablation of pancreatic neoplasms

Ablative therapies for locoregional treatment of pancreatic neoplastic lesions developed over the last decade to be applied during surgery are now becoming also available to be utilized under endoscopic ultrasound (EUS) guidance. The advantage of this approach is clear because of the close proximity of the EUS transducer to the target lesion, coupled with developments of specifically designed ablation devices, making the procedure minimally invasive, and potentially sparing patients from the morbidity of this method when performed surgically. EUS-guided ablative techniques that have been applied to pancreatic neoplastic cysts, pancreatic functional and non-functional neuroendocrine neoplasms and pancreatic ductal adenocarcinoma include ethanol injection, radiofrequency ablation (RFA), a combination of bipolar RFA and cryoablation, laser therapy (LT) and photodynamic therapy (PDT). Up to now, most of these procedures have been applied to patients at high surgical risk or who refused surgery. However, more studies evaluating some of these treatments also in selected patients not at surgical risk are becoming available. These studies will pave the road to apply this therapeutic approach to a more extensive number of patients, alone or in association with other therapies, such as immunomodulating drugs. The present manuscript will critically review the available evidence in the field of EUS-guided local ablative treatment of solid and cystic pancreatic neoplasms.

Locally Advanced Pancreatic Cancer: Percutaneous Management Using Ablation, Brachytherapy, Intra-arterial Chemotherapy, and Intra-tumoral Immunotherapy

PURPOSE OF REVIEW

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive neoplasms, bearing a terrible prognosis. Stage III tumors, also known as locally advanced pancreatic cancer (LAPC), are unresectable, and current palliative chemotherapy regimens have only modestly improved survival in these patients. At this stage of disease, interventional techniques may be of value and further prolong life. The aim of this review was to explore current literature on locoregional percutaneous management for LAPC.

RECENT FINDINGS

Locoregional percutaneous interventional techniques such as ablation, brachytherapy, and intra-arterial chemotherapy possess cytoreductive abilities and have the potential to increase survival. In addition, recent research demonstrates the immunomodulatory capacities of these treatments. This immune response may be leveraged by combining the interventional techniques with intra-tumoral immunotherapy, possibly creating a durable anti-tumor effect. This multimodality treatment approach is currently being examined in several ongoing clinical trials. The use of certain interventional techniques appears to improve survival in LAPC patients and may work synergistically when combined with immunotherapy. However, definitive conclusions can only be made when large prospective (randomized controlled) trials confirm these results.

Establishing an immunocompromised porcine model of human cancer for novel therapy development with pancreatic adenocarcinoma and irreversible electroporation

New therapies to treat pancreatic cancer are direly needed. However, efficacious interventions lack a strong preclinical model that can recapitulate patients’ anatomy and physiology. Likewise, the availability of human primary malignant tissue for ex vivo studies is limited. These are significant limitations in the biomedical device field. We have developed RAG2/IL2RG deficient pigs using CRISPR/Cas9 as a large animal model with the novel application of cancer xenograft studies of human pancreatic adenocarcinoma. In this proof-of-concept study, these pigs were successfully generated using on-demand genetic modifications in embryos, circumventing the need for breeding and husbandry. Human Panc01 cells injected subcutaneously into the ears of RAG2/IL2RG deficient pigs demonstrated 100% engraftment with growth rates similar to those typically observed in mouse models. Histopathology revealed no immune cell infiltration and tumor morphology was highly consistent with the mouse models. The electrical properties and response to irreversible electroporation of the tumor tissue were found to be similar to excised human pancreatic cancer tumors. The ample tumor tissue produced enabled improved accuracy and modeling of the electrical properties of tumor tissue. Together, this suggests that this model will be useful and capable of bridging the gap of translating therapies from the bench to clinical application.

Clinical Phase I/II Study: Local Disease Control and Survival in Locally Advanced Pancreatic Cancer Treated with Electrochemotherapy

Objective. To assess local disease control rates (LDCR) and overall survival (OS) in locally advanced pancreatic cancer (LAPC) treated with electrochemotherapy (ECT). Methods. Electrochemotherapy with bleomycin was performed in 25 LAPC patients who underwent baseline Magnetic Resonance Imaging (MRI) and/or Computed Tomography (CT) and Position Emission Tomography (PET) scans before ECT and 1 and 6 months post ECT. LDCR were assessed using Response Evaluation Criteria in Solid Tumors (RECIST 1.1) and Choi criteria. Needle electrodes with fixed linear (N-30-4B) or fixed hexagonal configurations (N-30-HG or I-40-HG or H-30-ST) or variable geometry (VGD1230 or VGD1240) (IGEA S.p.A., Carpi, Italy) were used to apply electric pulses. Pain evaluation was performed pre-ECT, after 1 month and after 6 months with ECT. Overall survival estimates were calculated by means of a Kaplan-Meier analysis. Results. At 1 month after ECT, 76% of patients were in partial response (PR) and 20% in stable disease (SD). Six months after ECT, 44.0% patients were still in PR and 12.0% in SD. A LDCR of 56.0% was reached six months after ECT: 13 patients treated with fixed geometry had a LDCR of 46.1%, while for the 12 patients treated with variable geometry, the LDCR was 66.7%. The overall survival median value was 11.5 months: for patients treated with fixed geometry the OS was 6 months, while for patients treated with variable geometry it was 12 months. Electrochemotherapy was well-tolerated and abdominal pain was rapidly resolved. Conclusions. Electrochemotherapy obtained good results in terms of LDCR and OS in LAPC. Multiple needle insertion in a variable geometry configuration optimized by pre-treatment planning determined an increase in LDCR and OS compared to a fixed geometry configuration.

Role of Radiofrequency Ablation in the Management of Unresectable Pancreatic Cancer

Pancreatic cancer is one of the most aggressive malignancies of the digestive tract and carries a poor prognosis. The majority of patients have advanced disease at the time of diagnosis. Surgical resection offers the only curative treatment, but only a small proportion of patients can undergo surgical resection. Radiofrequency ablation (RFA) is a well-known modality in the management of solid organ tumors, however, its utility in the management of pancreatic cancer is under investigation. Since the past decade, there is increasing use of RFA as it provides a feasible palliation treatment in the management of unresectable pancreatic cancer. RFA causes tumor cytoreduction through multiple mechanisms such as coagulative necrosis, protein denaturation, and activation of anticancer immunity. The safety profile of RFA is controversial because of the high risk for complications, however, small prospective and retrospective studies have shown promising results in its applicability for palliative management of unresectable pancreatic malignancies. In this review, we discuss different approaches of RFA, their indications, technical accessibility, safety, and major complications in the management of unresectable pancreatic cancer.

Endoscopic ultrasound-guided therapies for pancreatic solid tumors: An overview

The close proximity of the endoscopic ultrasound (EUS) probe to the pancreas, coupled with the ease with which a needle can be inserted into a pancreatic lesion, have contributed to the development of EUS-guided therapies for both adenocarcinoma and neuroendocrine pancreatic neoplasms. EUS-guided fine needle injection of different types of drugs, implantation of fiducial markers to facilitate stereotactic body radiation therapy or of radioactive seeds to perform brachytherapy, and the use of different thermal and nonthermal ablation devices and techniques have all been tested in preliminary human studies. This manuscript will present the available evidence accumulated thus far in the field of EUS-guided oncological treatment of pancreatic solid tumors, along with a look into possible future applications.

Interventional Endoscopic Ultrasound: Current Status and Future Directions

The evolution of endoscopic ultrasound (EUS) from a diagnostic to a therapeutic procedure has resulted in a paradigm shift toward endoscopic management of disease states that previously required percutaneous or surgical approaches. The past few years have seen additional techniques and devices that have enabled endoscopists to expand its diagnostic and therapeutic capabilities. Some of these techniques initially were reported more than a decade ago; however, with further device development and refinement in techniques there is potential for expanding the application of these techniques and new technologies to a broader group of interventional gastroenterologists. Lack of formalized training, devices, and prospective data regarding their use in addition to a scarcity of guidelines on implementation of these technologies into clinical practice are contributing factors impeding the growth of the field of interventional EUS. In April 2019, the American Gastroenterological Association's Center for Gastrointestinal Innovation and Technology conducted its annual Tech Summit and a key session focused on interventional EUS. This article is a White Paper generated from the conference, discusses the published literature pertaining to the topic of interventional EUS, and outlines a proposed framework for the implementation of interventional EUS techniques into clinical practice. Three primary areas of interventional EUS are addressed: (1) EUS-guided access; (2) EUS-guided tumor ablation; and (3) endohepatology. There was general agreement among participants on several key components. The introduction of these novel interventions requires better tools, more data on safety/outcomes, and improved training for endoscopists. Participants also agreed that widespread implementation and use of these techniques will require support from Gastrointestinal Societies and other key stakeholders including payers. Continued work by the Gastrointestinal Societies and manufacturers to provide training programs, appropriate equipment/work environments, and policies that motivate endoscopists to adopt new techniques is essential for growing the field of interventional EUS.

Endoscopic ultrasound guided hepatic interventions

Intervention for liver disease has predominantly been performed through the percutaneous approach. However, as endoscopic ultrasound (EUS) applications have expanded, there have emerged various EUS-guided interventions for liver disease, a space we call "Endo-Hepatology". EUS-guided liver biopsy can be considered the "forerunner" of Endo-Hepatology and has become a clinical option for patients requiring histologic diagnosis and staging of their liver disease. EUS also enables direct access to the portal vein. Subsequently, many procedures are being explored, such as angiography, measurement of the portosystemic pressure gradient, portal vein sampling to detect cancer cell or DNA, and EUS-guided transhepatic intrahepatic portosystemic shunt creation. Since the transducer is close to the liver, especially the left and caudate lobes, EUS can be used as a rescue when the percutaneous approach is not favorable and EUS-guided treatments of liver tumor, cyst and abscess have been reported. This review summarizes the available studies of EUS-guided intervention in the liver.

Interventional endoscopic ultrasound for pancreatic neuroendocrine neoplasms

The proximity of the endoscopic ultrasound (EUS) transducer to the pancreas and the possibility to place needles or other accessories into a target located adjacent to the wall of the GI tract have encouraged researchers to develop various EUS-guided local treatments directed towards pancreatic neuroendocrine neoplasms (PanNENs). The use of pre-operative EUS-guided tattooing or fiducial marker placement to facilitate intraoperative tumor localization has proven effective in reducing operative time of laparoscopic surgeries. To reduce the mortality and morbidity rates of surgical resection, which is presently the mainstay treatment of PanNENs. EUS-guided loco-regional treatments, such as injection of alcohol and radiofrequency ablation have been proposed and results are hitherto promising. The present paper summarizes currently available data in the field of EUS-guided interventions to pancreatic neuroendocrine tumors, as well as possible future applications.

Necrosis volume and Choi criteria predict the response to endoscopic ultrasonography-guided HybridTherm ablation of locally advanced pancreatic cancer

Background and study aims  Endoscopic ultrasound (EUS)-guided ablation of pancreatic ductal adenocarcinoma (PDAC) with HybridTherm-Probe (EUS-HTP) is feasible and safe, but the radiological response and ideal tool to measure it have not been investigated yet. The aims of this study were to: 1) assess the radiological response to EUS-HTP evaluating the vital tumor volume reduction rate, Response Evaluation Criteria in Solid Tumors (RECIST1.1) and Choi criteria; 2) determine the prognostic predictive yield of these criteria. Patients and methods  A retrospective analysis was performed of patients with locally advanced PDAC after primary treatment or unfit for chemotherapy prospectively treated by EUS-HTP. Computed tomography scan was performed 1 month after EUS-HTP to evaluate: 1) vital tumor volume reduction rate (VTVRR) by measuring necrosis and tumor volumes through a computer-aided detection system; and 2) RECIST1.1 and Choi criteria. Results  EUS-HTP was feasible in 22 of 31 patients (71 %), with no severe adverse events. Median post-HTP survival was 7 months (1 - 35). Compared to pre-HTP tumor volume, a significant 1-month VTVRR (mean 21.4 %) was observed after EUS-HTP ( P  = 0.005). We identified through ROC analysis a VTVRR > 11.46 % as the best cut-off to determine post-HTP 6-month survival outcome (AUC = 0.733; sensitivity = 70.0 %, specificity = 83.3 %). This cut-off was significantly associated with longer overall survival (HR = 0.372; P  = 0.039). According to RECIST1.1 and Choi criteria, good responders to EUS-HTP were 60 % and 46.7 %, respectively. Good responders according to Choi, but not to RECIST1.1, had longer survival (HR = 0.407; P  = 0.04). Conclusions  EUS-HTP induces a significant 1-month VTVRR. This effect is assessed accurately by evaluation of necrosis and tumor volumes. Use of VTVRR and Choi criteria, but not RECIST 1.1 criteria, might identify patients who could benefit clinically from EUS-HTP.

Standardization of a Radiofrequency Ablation Tool in an Ex-Vivo Porcine Liver Model

(1) Background: Preclinical and clinical data about a novel radiofrequency ablation (RFA) system (STARmed Co, Ltd.; Koyang, Korea) designed to be used under endoscopic ultrasound (EUS) control for pancreatic lesion ablation, are limited, obtained with non-standardized procedures and heterogeneous results. The aim of this study is to standardize the RFA procedure of this system in order to define the optimal ablation power and time. (2) Methods: RFA was performed on an ex-vivo porcine liver at different powers (40, 30, 20, 10 Watts (W)) and times (1, 3, 5, 7, 15 min) with a 1-centimeter monopolar electrode (perfused by chilled solution) positioned on the distal tip of a 19-Gauge needle. A blinded expert pathologist histologically analyzed each ablation area. (3) Results: The size of the total macroscopic ablated area was negatively correlated with ablation power (R −0.74): the largest was obtained at 10 W (p = 4.7 × 10−4) for longer times (R 0.92; p = 8.9 × 10−8). Central histologic coagulative necrosis did not differ among ablation settings (mean size 3.25 mm). External “parenchymal hypochromia” or “diaphanization” resulted the widest at 10 W, for longer times (R 0.8, p = 3.6 × 10−4). (4) Conclusions: The RFA system can produce small sizes of coagulative necrosis, regardless of the setting. Larger areas of diaphanization surrounding the necrosis can be produced at lower powers for longer times.

The safety and efficacy of endoscopic ultrasound-guided ablation therapy for solid pancreatic tumors: a systematic review

BACKGROUND AND AIMS

Recently, endoscopic ultrasound (EUS)-guided ablation therapy, as a minimally invasive technique, has shown its potential to substitute surgery in treating solid pancreatic tumors, such as small potential malignant pancreatic tumors, small insulinomas and locally advanced pancreatic ductal adenocarcinoma (LAPDAC). Therefore, we conducted this systematic review to assess the safety and efficacy of EUS-guided ablation therapy for solid pancreatic tumors.

METHODS

We conducted a comprehensive search of PubMed, Embase, Cochrane library and Web of Science databases from inception to February 2020. The endpoints were clinical success and complications rates. The pooled event rate was calculated using Comprehensive Meta Analysis software.

RESULTS

Fourteen studies with a total of 158 patients were included in our final analysis. The major types of solid pancreatic tumors were nonfunction pancreatic neuroendocrine tumors (n = 78, 49.4%), LAPDAC (n = 48, 30.4%) and insulinomas (n = 26, 16.5%). Overall, the pooled clinical success rate was 85.9% (95% confidence interval (CI): 75.4-92.4%, I ² = 25.18%), pooled complications rate was 29.1% (95% CI: 18.6-42.3%, I ² = 50.40%). Subgroup analysis was performed based on ablation methods, which showed clinical success rate for radiofrequency ablation (RFA) was 83.5% (95% CI: 67.9-92.4%), and 87.9% (95% CI: 66.2-96.4%) for ethanol ablation (EA). In terms of complications rate, it was 32.2% (95% CI: 19.4-48.4%) for RFA, and 21.2% (95% CI: 6.8-49.9%) for EA.

CONCLUSIONS

EUS-guided ablation therapy is a promising alternative treatment for solid pancreatic tumors, especially for p-NETs and insulinomas < 2 cm, with rarely severe complications. Further prospective studies with long-term follow-up are warranted in future.

Endoscopic Ultrasound-Guided Local Therapy for Pancreatic Neoplasms

Surgical resection is considered the only treatment option for pancreatic cancer and other pancreatic neoplasms with malignant potential, such as neuroendocrine tumors, mucinous cystic neoplasms, and intraductal papillary mucinous neoplasms. However, only 10%-20% of all patients with pancreatic cancer present with resectable forms of the disease as the symptoms are rarely manifested during the early stages, and the disease tends to progress rapidly. Furthermore, pancreatic surgery is associated with high rates of morbidity and mortality. The development of linear-array endoscopic ultrasound (EUS) techniques has increased the indications of EUS-guided local therapy for pancreatic neoplasms. We assessed the studies that investigated various treatment modalities, such as fine-needle injection, radiofrequency ablation, irreversible electroporation, and radiotherapy, under EUS guidance to better understand the usefulness of these techniques with respect to the efficacy and associated complications.

Imaging response evaluation after local ablative treatments in locally advanced pancreatic cancer: an expedited systematic review

BACKGROUND

Several local ablative modalities have been introduced for the treatment of locally advanced pancreatic cancer (LAPC). However, there is no consensus on how to evaluate the imaging response after treatment. A systematic review was performed regarding the use of imaging for response assessment in LAPC.

METHODS

A systematic literature search was conducted in PubMed. Studies reporting imaging outcomes were included in the review. Studies were excluded if the imaging outcomes could not be differentiated between different disease stages, tumor histology or surgical approaches.

RESULTS

Thirty-four studies were included in the analysis. Fourteen studies used standardized response criteria, while six studies did not report the response evaluation method. The rest used self-determined criteria, absolute size comparisons or similar methods. One study found a correlation between early systemic progression (<6 months) and overall survival.

CONCLUSION

There was notable variation in the use of imaging for response assessment in LAPC. This significantly hinders cross-comparison of results among studies. There is currently only sparse evidence of an association between imaging responses and overall survival. The field calls for standardized recommendations regarding the choice of response assessment method, timing of scans, target definition and reporting of outcomes.

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.

Systematic review of endoscopy ultrasound-guided thermal ablation treatment for pancreatic cancer

The development of curvilinear-array EUS and EUS-guided fine-needle aspiration (EUS-FNA) has led these approaches to become interventional procedures rather than purely diagnostic, as a minimally invasive antitumor therapeutic alternative to radiological and surgical treatments. The possibility to accurately position needle devices and to reach a deep target like the pancreas gland under real-time imaging guidance has expanded the use of EUS to ablate tumors. Currently, a variety of probes specifically designed for EUS ablation are available, including radiofrequency, hybrid cryothermal ablation (combining radiofrequency with cryotechnology), photodynamic therapy, and laser ablation. To date, several studies have demonstrated the safety and feasibility of these ablation techniques in the pancreatic setting, but only a few small series on pancreatic thermal ablation under EUS guidance are available. EUS-guided thermal ablation is primarily used for pancreatic cancer. It is well suited to this disease because of its superior anatomical access compared with other imaging modalities and the dismal prognosis despite improvements in chemoradiotherapy and surgery in the management of pancreatic cancer. Other targets are pancreatic neuroendocrine tumors and pancreatic cystic neoplasms, which are curable by surgical resection, but some patients are poor surgical candidates or prefer conservative management. This is a literature review of previously published clinical studies on EUS-guided thermal ablative therapies. Data on the long-term efficacy of EUS-guided antitumor thermal ablation therapy and large prospective randomized studies are still needed to confirm the real clinical benefits of these techniques for the management of pancreatic neoplasms.

Prophylactic dendritic cell vaccination controls pancreatic cancer growth in a mouse model

PURPOSE

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-related deaths with high recurrence after surgery due to a paucity of effective post-surgical adjuvant treatments. DC vaccines can activate multiple anti-tumor immune responses but have not been explored for post-surgery PDAC recurrence. Intraperitoneal (IP) delivery may allow increased DC vaccine dosage and migration to lymph nodes. Here, we investigated the role of prophylactic DC vaccination controlling PDAC tumor growth with IP delivery as an administration route for DC vaccination.

METHODS

DC vaccines were generated using ex vivo differentiation and maturation of bone marrow-derived precursors. Twenty mice were divided into four groups (n = 5) and treated with DC vaccines, unpulsed mature DCs, Panc02 lysates or no treatment. After tumor induction, mice underwent three magnetic resonance imaging scans to track tumor growth. Apparent diffusion coefficient (ADC), a quantitative magnetic resonance imaging measurement of tumor microstructure, was calculated. Survival was tracked. Tumor tissue was collected after death and stained with hematoxylin and eosin, Masson's trichrome, terminal deoxynucleotidyl transferase dUTP nick end labeling and anti-CD8 stains for histology.

RESULTS

DC-vaccinated mice demonstrated stronger anti-tumor cytotoxicity compared with control groups on lactate dehydrogenase assay. DC vaccine mice also demonstrated decreased tumor volume, prolonged survival and increased ΔADC compared with control groups. On histology, the DC vaccine group had increased apoptosis, increased CD8+ T cells and decreased collagen. ΔADC negatively correlated with % collagen in tumor tissues.

DISCUSSION

Prophylactic DC vaccination may inhibit PDAC tumor growth during recurrence and prolong survival. ΔADC may be a potential imaging biomarker that correlates with tumor histological features.

Endoscopic ultrasound in pancreatic cancer treatment: Facts and hopes

Pancreatic ductal adenocarcinoma is one of the most common causes of cancer-related deaths. Since most patients present with advanced disease, its prognosis is dismal. New and more effective therapeutic strategies are needed. Endoscopic ultrasound is currently an indispensable tool for the diagnosis and staging of pancreatic ductal adenocarcinoma. In recent years, endoscopic ultrasound has evolved to become also a therapeutic procedure. On one hand, the role of endoscopic ultrasound in the management of pancreatic cancer-related symptoms (pain, obstructive jaundice, and gastric outlet obstruction) is now well established. On the other hand, its use as a mean to the delivery of anti-tumor therapies (injecting anti-tumor agents, assisting in radiotherapy, and guiding ablative therapies) is still mostly experimental, despite growing evidence supporting its feasibility, safety and efficacy.

Endoscopic Ultrasound-Guided Ablation of Liver Tumors

"Endoscopic ultrasound (EUS)-guided ablative therapies have advanced significantly and have led to experimental applications in locations that have been difficult to image and/or reach with percutaneous approaches, such as the caudate and left lobe of the liver. EUS-guided treatments of the liver are under development. The literature has shown that many percutaneous ablative techniques are readily adaptable for EUS. In this review, the authors discuss the current developments on EUS-guided ablation of liver tumors, including injection of sclerosants, thermal therapy, and EUS-guided portal injection of chemotherapy."

EUS-guided pancreatic radiofrequency ablation: preclinical comparison of two currently available devices in a pig model

Introduction  Two devices are currently available to perform pancreatic radiofrequency ablation (P-RFA). Potential clinical indications might extend from the treatment of pancreatic cystic lesions to ablation of small pancreatic solid lesions or cytoreduction of advanced pancreatic adenocarcinomas, but more preclinical data from animal models are needed to optimize P-RFA operation. Methods  P-RFA was performed under laparotomy and under endoscopic ultrasonographic guidance on the liver and pancreatic parenchyma of four live swine using the Habib EUS RFA (EMcision Ltd, London, UK) probe and the EUS-RA needle (Taewoong Medical, Gyeonggi-do, South Korea). Animals were sacrificed 2 hours after the procedure. Influence of tuning ablation time and power on tissue ablation were studied by histopathological assessment of the maximal depth of tissue damage on representative slides for each P-RFA shot. Results  The Habib probe in the liver parenchyma resulted in tissue necrosis increasing within the range of 1.9 ± 0.5 mm (Power = 8 W, Time = 120 s) to 2.5 ± 1 mm (Power = 10 W, Time = 120 s). In the pancreatic parenchyma, tissue damage ranged from 3.1 ± 0.4 mm (Power = 8 W, Time = 120 s) to 2.3 ± 0.1 mm (12 W, 120 s) in depth. EUS RFA ablation of the liver parenchyma resulted in tissue damage ranging from 1.6 ± 0.2 mm (Power = 30 W, Time = 11 s) to 1.5 ± 0.1 mm (Power = 70 W, Time = 9 s); in the pancreas, ablation depth ranged from 3.6 ± 0.5 mm (Power = 30 W, Time = 15 s) to 3.8 ± 0.4 mm (Power = 70 W, Time = 11 s). Conclusion  Both devices allow for effective ablation of pancreatic tissue within 1.5 to 3.8 mm around the RFA electrode, with a modest influence of tuning power settings. Specific settings are recommended for each of the devices studied. Ablation of larger lesions may require more repeat P-RFA shots in different locations rather than a simple modulation of ablation parameters.

Phase 1 study of EUS-guided photodynamic therapy for locally advanced pancreatic cancer

BACKGROUND AND AIMS

Locally advanced pancreatic cancer (LAPC) has a poor prognosis. There are limited data describing the use of photodynamic therapy (PDT) for pancreatic cancer in humans. We hypothesized that EUS-guided PDT for LAPC is safe, technically feasible, and produces a dose- and time-dependent increasing degree of image-defined tumor necrosis.

METHODS

In a single-center, prospective, dose-escalation phase 1 study, patients with treatment-naïve LAPC received intravenous porfimer sodium (Concordia Laboratories Inc, St Michael, Barbados) followed 2 days later by EUS-PDT. EUS-PDT was performed by puncture with a 19-gauge needle and insertion of a 1.0-cm light diffuser (Pioneer Optics, Bloomfield, Conn) and illumination with a 630-nm light (Diomed Inc, Andover, Mass). A CT scan 18 days after PDT was done to assess for change in pancreatic necrosis. Nab-paclitaxel (125 mg/ m² intravenously) and gemcitabine (1000 mg /m² intravenously) were initiated 7 days after CT and given weekly for 3 of 4 weeks (1 cycle) until disease progression or unacceptable toxicity.

RESULTS

Twelve patients (mean age, 67 ± 6 years; 8 male) with tumors (mean diameter, 45.2 ± 12.9 mm) in the head and/or neck (8) or body and/or tail (4) underwent EUS-PDT. Compared with baseline imaging, increased volume and percentage of tumor necrosis were observed in 6 of 12 patients (50%) after EUS-PDT. The mean overall increases in volume and percentage necrosis were 10 ± 26 cm³ (P = .20) and 18% ± 22% (P = .016), respectively. After a median follow-up of 10.5 months (range, 1.0-37.4 months), median progression-free (PFS) and overall survival (OS) were 2.6 months (95% confidence interval, 0.7, not estimable) and 11.5 months (95% confidence interval, 1.1, 16.9), respectively. Surgical resection was attempted in 2 patients, and pathology showed a complete response (n = 1) and residual 2-mm tumor (n = 1). There were 8 serious adverse events and none related to EUS or EUS-PDT.

CONCLUSION

EUS-PDT for LAPC appears to be safe and produces measurable imaged-defined tumor necrosis. Phase 2 studies are warranted. (Clinical trial registration number: NCT01770132.).