Endoscopic ultrasonography-guided tumor ablation

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.

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 <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.

Spannungsfeld endoskopische Resektionsverfahren bei GEP-NET // Endoscopic resection for GEP-NET

Neuroendokrine Tumoren des Verdauungstraktes (GEP-NET) sind eine seltene Tumorentität, die häufig als Zufallsbefund diagnostiziert werden. Ein großer Teil dieser Zufallsdiagnosen wird im Rahmen einer endoskopischen Untersuchung gestellt. Während die vollständige Entfernung des Tumors im Sinne einer kurativen chirurgischen Resektion nach onkologischen Kriterien das Standardvorgehen für lokalisierte Tumorerkrankungen ist, kann bei kleinen Tumoren ohne Hinweis und Risiko für eine lymphogene Metastasierung eine endoskopische Abtragung in gleicher Intention erfolgen. Während dies für Magen-, Duodenum- und Rektum-NET der Standard ist, sollten NET des Jejunums und Ileums aufgrund der hohen Metastasierungsrate trotz geringer Tumorgröße regelhaft nicht endoskopisch angegangen werden. Die Grenze für eine endoskopische Resektion ergibt sich sowohl durch die technische Machbarkeit im Sinne des Erreichens einer R0-Resektion, der erwarteten Komplikationen im Sinne von Blutung und Perforationen als auch durch das vermutete Risiko für eine lymphogene Metastasierung. Generell wird eine endoskopische Resektion bei Befunden < 1 cm regelhaft empfohlen, da sowohl die gute technische Machbarkeit als auch das geringe Metastasierungsrisiko für eine endoskopische Resektion sprechen. Bei allen Befunden über 2 cm Größe sind sowohl die technischen Erfolgsaussichten so niedrig als auch das Metastasierungsrisiko so hoch, dass in dieser Situation regelhaft ein chirurgisches Vorgehen erfolgen sollte. Es bleibt somit ein Graubereich bei der Tumorgröße zwischen 1 und 2 cm, wo sowohl endoskopische, aber auch chirurgische Resektionsverfahren sinnvoll eingesetzt werden können. Zunehmend kommen auch gemeinsame Eingriffe im Sinne eines endoskopisch-laparoskopischen Rendezvous-Verfahrens zum Einsatz – insbesondere im Duodenum bieten sich diese Eingriffe an, um eine minimale Resektion mit größtmöglicher R0-Erfolgsrate und niedriger Perforationsrate zu erreichen.

State of the Art in Endoscopic Therapy for the Management of Gastroenteropancreatic Neuroendocrine Tumors

OPINION STATEMENT

Gastroenteropancreatic neuroendocrine neoplasms (GEP NENs) comprise a heterogeneous group of slow growing tumors arising from the neuroendocrine cells of the gastrointestinal (GI) tract. Although they are considered relatively rare, their incidence is rising and it is believed that the more frequent use of endoscopy and imaging studies have at least in part contributed to the increased diagnosis especially of localized neoplasms. The management of these neoplasms should be guided by a multidisciplinary NEN team following appropriate staging investigations. Localized neoplasms of the GI tract may be suitable for endoscopic therapy, while patients with pancreatic NENs, unsuitable for surgery, should be considered for endoscopic ultrasound (EUS)-guided ablation. In this review, we discuss the evidence regarding endoscopic resection of luminal NENs and EUS-guided therapy of pancreatic NENs. The efficacy, safety, and other longer-term outcomes of these techniques are summarized. In conclusion, this review of endoscopic therapies for localized NENs may be a useful guide for NEN clinicians and endoscopists who are considering these therapeutic options for the management of focal GEP NENs.

Surgical outcomes are hampered after endoscopic ultrasonography-guided ethanol lavage and/or Taxol injection in cystic lesions of the pancreas

Backgrounds/Aims

Endoscopic ultrasonography-guided ethanol lavage and Taxol injection (EUS-ELTI) for pancreatic cystic lesions have been recently performed in some medical centers. The aim of this study was to optimize patient selection and analyze outcomes of patients who underwent surgeries after EUS-ELTI for pancreatic cystic lesions.

Methods

Among 310 patients who underwent EUS-ELTI between January 2007 and December 2014, 23 underwent surgeries after EUS-ELTI owing to incomplete treatment and/or adverse events. Surgical outcomes of patients who underwent surgeries after EUSELTI were evaluated. Clinical outcomes of patients who underwent surgeries after EUS-ELTI were then retrospectively compared with those of patients who underwent upfront surgery for left-sided pancreatic lesions without an EUS-ELTI procedure.

Results

The pathology revealed degenerated cysts in 12 patients, mucinous cyst neoplasms in five, neuroendocrine tumors in two, intraductal papillary mucinous neoplasm (IPMN) in one, solid pseudopapillary tumor in one, pancreatic ductal adenocarcinoma arising from an IPMN in one, and hepatoid carcinoma in one. Twelve patients underwent laparoscopic distal pancreatectomy and five patients underwent open distal pancreatectomy. When clinical outcomes were retrospectively compared between patients who underwent laparoscopic distal pancreatectomy after EUS-ELTI and those who did not receive an EUS-ELTI procedure, the spleen-preserving rate was 0% in the EUS-ELTI group and 61.7% (365/592) in the control group (p < 0.001).

Conclusions

Surgical outcomes are compromised after EUS-ELTI for cystic tumor of the pancreas. Further studies are needed to investigate the efficacy and safety of the EUS-ELTI procedure.

Endoscopic Ultrasound-Guided Treatment of Pancreatic Cancer

PURPOSE OF REVIEW

The aim of this review is to evaluate the emerging role of endoscopic ultrasound (EUS) in the guidance of tumor-targeted therapies for patients with pancreatic cancer (PC).

RECENT FINDINGS

EUS-guided ablation, brachytherapy, fiducial marker placement, and antitumor agent injection have been described to date. EUS-guided fiducial placement for SBRT in pancreatic cancer has entered the clinical practice and is performed at many centers clinically without a research protocol. EUS-guided brachytherapy and RFA have been shown to be feasible and safe procedures, and potentially offer local disease control. Other potential techniques of EUS-guided treatment of pancreatic cancer are still considered experimental, with many of them appearing to be safe and reasonably well tolerated. However, their effectiveness and exact role in oncological treatment have yet to be established. Clinical trials with many of the techniques/agents described are underway and multicentric randomized trials with prospective design are eagerly awaited.

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.

Treatment response and preliminary efficacy of hepatic tumour laser ablation under the guidance of percutaneous and endoscopic ultrasonography

Background

Studies focusing on the treatment effectiveness of endoscopic ultrasonography (EUS)-guided laser ablation (LA) for hepatic tumours or the technical differences from percutaneous ultrasonography (US)-guided LA are lacking. The objective of this study was to evaluate the treatment response and preliminary efficacy of US- and EUS-guided LA for hepatic tumours.

Methods

We performed a prospective analysis of treatment response and preliminary efficacy in 92 consecutive patients who underwent US-LA and EUS-LA from January 2015 to June 2017. The primary endpoint was complete tumour ablation (CTA). The secondary endpoint was 12-month local tumour progression (LTP).

Results

Among a total of 120 hepatic lesions, 20 lesions were ablated under the guidance of EUS. The application of the multi-fibre technique (0, 0% vs. 69, 69.0%, p < 0.01), tumours located in the left lobe (18, 90.0% vs. 28, 28.0%, p < 0.01) and multi-session ablation (4, 20.0% vs. 4, 4.0%, p = 0.009) were factors found to be significantly different between the EUS-LA and US-LA groups. The CTA was achieved in 94% of patients in the US-LA group and 100% of patients in the EUS-LA group (p = 0.261). Twelve-month LTP was observed in 8.5% of the patients in the US-LA group and 15.0% of the patients in the EUS-LA group with no significant difference between the two groups (p = 0.372). The multivariate analysis identified that the tumour diagnosis (p = 0.004; 95% CI, 0.039–0.547) was the only independent risk factor associated with 12-month LTP.

Conclusions

Patients in the EUS-LA and US-LA groups shared as similar treatment response and preliminary efficacy in the treatment of hepatic tumours. A hybrid LA approach to nonsurgical hepatic tumours appeared to be reasonable.

Endoscopic ultrasonography (EUS)-guided laser ablation (LA) of adrenal metastasis from pancreatic adenocarcinoma

Endoscopic ultrasonography (EUS)-guided laser ablation (LA) is potentially applicable to tumours in the left lobe of the liver and pancreas. This report seeks to introduce the novel use of EUS-guided LA for left adrenal metastases from pancreatic adenocarcinoma. A 70-year-old female was referred to our hospital for dull abdominal pain and tiredness for 1 month. Computed tomography (CT) discovered a 1.0 × 1.7 cm mass in the area of the left adrenal gland. The lesion was highly suspicious for metastasis due to her history of pancreatic adenocarcinoma 1 year ago, which was removed through radical surgery. Intraoperative frozen-section pathology revealed a tumour invading the left adrenal gland. The left adrenal mass was clearly visualised on EUS and exhibited irregular hyper-enhancement during contrast. The tumour was successfully treated by four sessions of EUS-guided LA. After the procedure, symptomatic relief was achieved and remained. At the 4-month follow-up, contrast-enhanced CT revealed that the volume of the target was significantly decreased. Here, we introduced a new method for left adrenal metastasis using thermal ablation through EUS. As a potential alternative access to the percutaneous approach, EUS-guided LA may provide a minimally invasive treatment to relieve the tumour burdens and symptoms when applied accurately.

Antitumor Activity of Intratumoral Ethanol Injection in an Orthotopic Pancreatic Cancer Cell Mouse Xenograft Model

Purpose

Pancreatic cancer is a lethal disease and usually is diagnosed at advanced stages of disease. This study assessed the effects of intratumoral ethanol injection using an endoscopic ultrasound (EUS) probe on the control of pancreatic cancer in a mouse orthotopic xenograft model.

Materials and Methods

The subcutaneous and orthotopic human pancreatic cancer cell mouse xenograft models were established. Different concentrations of ethanol (0–95%) were injected into subcutaneous xenograft tumors. In the orthotopic tumor model, ethanol was injected into the tumor lesions under the guidance of a high-frequency EUS probe. Tumor volume, relative tumor volume (RTV), and histopathology were evaluated. The serum amylase level was analyzed at baseline and 24 h after treatment in the orthotopic tumor model.

Results

Injection of 40–95% ethanol induced tumor necrosis in the subcutaneous tumor model, while there was no statistical difference between the RTVs of the two groups (P = 0.81). In the orthotopic tumor model, the RTV of the 80% ethanol treatment group was less than that of the saline injection group (P < 0.01); and histologically, there was a large area of necrosis observed in the 80% ethanol group. The serum amylase level was slightly elevated at 24 h after injection and returned to the baseline level at 7 days.

Conclusion

Injection of 80% ethanol into xenograft tumor lesions of orthotopic pancreatic cancer resulted in tumor necrosis, and the procedure was safe and effective. Future studies will further confirm its antitumor activity as well as assess its safety and feasibility.

Utility of endoscopic ultrasound and endoscopy in diagnosis and management of hepatocellular carcinoma and its complications: What does endoscopic ultrasonography offer above and beyond conventional cross-sectional imaging?

Hepatocellular carcinoma constitutes over 90% of the primary liver tumors, the rest being cholangiocarcinoma. It has an insidious presentation, which is responsible for the delayed presentation. Hence, the management strategy relies on screening to diagnose it an early stage for curative resection and/or treatment with local ablative techniques or chemotherapy. However, even with different screening programs, more than 60% of tumors are still detected at an advanced stage, leading to an unchanged mortality rate, thereby implying a room for improvement in the screening and diagnostic process. In the last few years, there has been evolution of utility of endoscopy, specifically endoscopic ultrasonography along with Fine needle aspiration, for this purpose, which we comprehensively review in this article.

Onsite evaluation of endoscopic ultrasound fine needle aspiration: the endosonographer, the cytotechnologist and the cytopathologist

Endoscopic ultrasound guided fine needle aspiration (EUS-FNA) has become an essential tool in the management of multiple diseases. Its accuracy is related to different aspects of the technique, one of the most important being the experience and interaction of the endosonographer and pathologist. Certain studies over the past years have highlighted the importance of having rapid on-site evaluation (ROSE) of samples obtained at the time of EUS-FNA. We have reviewed the role of ROSE, performed by the same endosonographer, a cytotechnologist and an expert cytopathologist. The available data suggest that ROSE (either by the endosonographer, the cytotechnologist, or the cytopathologist) improves sample adequacy and diagnostic yield, with the best option to have ROSE performed by an expert cytopathologist. However, if non-ROSE accuracy is already very high, any improvement is harder to achieve.

Endoscopic ultrasound-guided radiofrequency ablation in gastroenterology: New horizons in search

Radiofrequency ablation (RFA) has been widely used for the treatment of various solid organ malignancies. Over the last decade, endosonographers have gradually shifted the application of RFA from porcine models to humans to treat a spectrum of diseases. RFA is performed in patients with pancreatic carcinoma who are not candidates for surgery. In this paper, we will discuss various indications for RFA, its procedural details and complications. At present, endoscopic ultrasound-guided RFA is gradually incorporated into the management of various diseases and opens a new avenue for disease treatment.

Theoretical investigation of transgastric and intraductal approaches for ultrasound-based thermal therapy of the pancreas

Background

The goal of this study was to theoretically investigate the feasibility of intraductal and transgastric approaches to ultrasound-based thermal therapy of pancreatic tumors, and to evaluate possible treatment strategies.

Methods

This study considered ultrasound applicators with 1.2 mm outer diameter tubular transducers, which are inserted into the tissue to be treated by an endoscopic approach, either via insertion through the gastric wall (transgastric) or within the pancreatic duct lumen (intraductal). 8 patient-specific, 3D, transient, biothermal and acoustic finite element models were generated to model hyperthermia (n = 2) and ablation (n = 6), using sectored (210°–270°, n = 4) and 360° (n = 4) transducers for treatment of 3.3–17.0 cm³ tumors in the head (n = 5), body (n = 2), and tail (n = 1) of the pancreas. A parametric study was performed to determine appropriate treatment parameters as a function of tissue attenuation, blood perfusion rates, and distance to sensitive anatomy.

Results

Parametric studies indicated that pancreatic tumors up to 2.5 or 2.7 cm diameter can be ablated within 10 min with the transgastric and intraductal approaches, respectively. Patient-specific simulations demonstrated that 67.1–83.3% of the volumes of four sample 3.3–11.4 cm³ tumors could be ablated within 3–10 min using transgastric or intraductal approaches. 55.3–60.0% of the volume of a large 17.0 cm³ tumor could be ablated using multiple applicator positions within 20–30 min with either transgastric or intraductal approaches. 89.9–94.7% of the volume of two 4.4–11.4 cm³ tumors could be treated with intraductal hyperthermia. Sectored applicators are effective in directing acoustic output away from and preserving sensitive structures. When acoustic energy is directed towards sensitive structures, applicators should be placed at least 13.9–14.8 mm from major vessels like the aorta, 9.4–12.0 mm from other vessels, depending on the vessel size and flow rate, and 14 mm from the duodenum.

Conclusions

This study demonstrated the feasibility of generating shaped or conformal ablative or hyperthermic temperature distributions within pancreatic tumors using transgastric or intraductal ultrasound.

Endoscopic Ultrasound-Guided Direct Intervention for Solid Pancreatic Tumors

Development and use of linear-array echoendoscope and endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) have made endoscopic ultrasound (EUS) more of an interventional procedure than a purely diagnostic procedure. This is a literature review of previously published clinical studies on EUS-guided direct intervention for solid pancreatic tumors, including EUS-guided fine needle injection (EUS-FNI) of antitumor agents, EUS-guided fiducial marker placement, EUS-guided brachytherapy and EUS-guided tumor ablation.

Endoscopy-guided ablation of pancreatic lesions: Technical possibilities and clinical outlook

Endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP)-guided ablation procedures are emerging as a minimally invasive therapeutic alternative to radiological and surgical treatments for locally advanced pancreatic cancer (LAPC), pancreatic neuroendocrine tumours (PNETs), and pancreatic cystic lesions (PCLs). The advantages of treatment under endoscopic control are the real-time imaging guidance and the possibility to reach a deep target like the pancreas. Currently, radiofrequency probes specifically designed for ERCP or EUS ablation are available as well as hybrid cryotherm probe combining radiofrequency with cryotechnology. To date, many reports and case series have confirmed the safety and feasibility of that kind of ablation technique in the pancreatic setting. Moreover, EUS-guided fine-needle injection is emerging as a method to deliver ablative and anti-tumoral agents inside the tumuor. Ethanol injection has been proposed mostly for the treatment of PCLs and for symptomatic functioning PNETs, and the use of gemcitabine and paclitaxel is also interesting in this setting. EUS-guided injection of chemical or biological agents including mixed lymphocyte culture, oncolytic viruses, and immature dendritic cells has been investigated for the treatment of LAPC. Data on the long-term efficacy of these approaches, and large prospective randomized studies are needed to confirm the real clinical benefits of these techniques for the management of pancreatic lesions.

Endoscopic Ultrasound-Guided Radiofrequency Ablation of the Pancreatic Tumors: A Promising Tool in Management of Pancreatic Tumors

Objective. Radiofrequency ablation is a well-established antitumor treatment and is recognized as one of the least invasive therapeutic modalities for pancreatic neoplasm. Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) delivery can be used to treat both pancreatic cancer and asymptomatic premalignant pancreatic neoplasms and may serve as a less invasive alternative to surgical resection. This is an appealing option that may result in less morbidity and mortality. The aim of this review was to summarize and evaluate the clinical and technical effectiveness of EUS-guided RFA of pancreatic neoplasms. Methods. A through literature review was performed to identify the studies describing this novel technique. In this review article, we have summarized human case series. The indications, techniques, limitations, and complications reported are discussed. Results. A total of six studies were included. Overall, a 100% technical success rate was reported in human studies. Complications related to endoscopic ultrasound-guided radiofrequency ablation delivery have been described; however, few cases have presented life-threatening outcomes. Conclusion. We believe that this novel technique can be a safe and effective alternative approach in the management of selected patients.

Initial experience of EUS-guided radiofrequency ablation of unresectable pancreatic cancer

BACKGROUND AND AIMS

Radiofrequency ablation (RFA) has been used as a valuable treatment modality for various unresectable malignancies. EUS-guided radiofrequency ablation (EUS-RFA) of the porcine pancreas was reported to be feasible and safe in our previous study, suggesting that EUS-RFA may be applicable as an adjunct and effective alternative treatment method for unresectable pancreatic cancer. This study aimed to assess the technical feasibility and safety of EUS-RFA for unresectable pancreatic cancer.

METHODS

An 18-gauge endoscopic RFA electrode and a radiofrequency generator were used for the procedure. The length of the exposed tip of the RFA electrode was 10 mm. After insertion of the RFA electrode into the mass, the radiofrequency generator was activated to deliver 20 to 50 W ablation power for 10 seconds. Depending on tumor size, the procedure was repeated to sufficiently cover the tumor.

RESULTS

EUS-RFA was performed successfully in all 6 patients (median age 62 years, range 43-73 years). Pancreatic cancer was located in the head (n = 4) or body (n = 2) of the pancreas. The median diameter of masses was 3.8 cm (range 3cm-9cm). Four patients had stage 3 disease, and 2 patients had stage 4 disease. After the procedure, 2 patients experienced mild abdominal pain, but there were no other adverse events such as pancreatitis or bleeding.

CONCLUSIONS

EUS-RFA could be a technically feasible and safe option for patients with unresectable pancreatic cancer.

Evaluation of radiofrequency ablation using the 1-Fr wire electrode in the porcine pancreas, liver, gallbladder, spleen, kidney, stomach, and lymph nodes: A pilot study

OBJECTIVES

The frequency of detecting asymptomatic incidental lesions of the pancreas is increasing. A substantial number of these lesions are either malignant or premalignant, thus mandating pancreatic resection. A less invasive treatment option may be feasible for selected patients. Endoscopic ultrasound-guided radiofrequency ablation (RFA) may be offered as a treatment option for these patients. The objective of this study was to evaluate the performance characteristics of monopolar RFA using a 1-Fr wire electrode in the porcine pancreas, liver, gallbladder, spleen, kidney, stomach, and lymph nodes.

METHODS

Six Yorkshire pigs were used for this study. The internal organs were accessed after a midline laparotomy. Manual monopolar RFAs were performed over a 90-second period using a wide range of power settings (3, 4, 5, 10, 15, and 25 W). The pancreas was exposed at all power settings; the other organs were exposed at power settings of 3, 4, 5, and 10 W. The maximum diameter of coagulative necrosis was measured.

RESULTS

In all study animals, RFA was performed in the target organs without difficulty. Only the pancreas showed definite coagulative necrosis. The maximum diameter of coagulative necrosis (8.0±1.7 mm) was achieved at 5 W. No definite coagulative necrosis was noted in the other organs.

CONCLUSIONS

Monopolar RFA using a 1-Fr wire electrode resulted in coagulative necrosis in the porcine pancreas. RFA in higher power settings resulted in relatively homogeneous necrosis. At a given power setting, the RFA effect is likely to be differ according to electrical properties of the target tissue. This article is protected by copyright. All rights reserved.

Pancreatic Solid and Cystic Neoplasms: Diagnostic Evaluation and Intervention

High-resolution imaging modalities, such as multi-detector computed tomography, MR imaging, and endoscopic ultrasound, are frequently used alone or in combination to characterize focal solid and cystic pancreatic neoplasms. Imaging in solid pancreatic neoplasms, typically adenocarcinoma and neuroendocrine tumors, is primarily used to detect and stage the extent of the tumor and to determine if complete surgical resection for cure is feasible. In cystic pancreatic masses, imaging aims to differentiate benign nonmucinous cystic lesions from potentially or frankly malignant mucin-producing cysts. Several noninvasive and invasive treatment options can be performed if surgical resection is not possible or contraindicated.

Endoscopic ultrasound guided radiofrequency ablation, for pancreatic cystic neoplasms and neuroendocrine tumors

AIM

To outline the feasibility, safety, adverse events and early results of endoscopic ultrasound (EUS)-radiofrequency ablation (RFA) in pancreatic neoplasms using a novel probe.

METHODS

This is a multi-center, pilot safety feasibility study. The intervention described was radiofrequency ablation (RF) which was applied with an innovative monopolar RF probe (1.2 mm Habib EUS-RFA catheter) placed through a 19 or 22 gauge fine needle aspiration (FNA) needle once FNA was performed in patients with a tumor in the head of the pancreas. The Habib™ EUS-RFA is a 1 Fr wire (0.33 mm, 0.013") with a working length of 190 cm, which can be inserted through the biopsy channel of an echoendoscope. RF power is applied to the electrode at the end of the wire to coagulate tissue in the liver and pancreas.

RESULTS

Eight patients [median age of 65 (range 27-82) years; 7 female and 1 male] were recruited in a prospective multicenter trial. Six had a pancreatic cystic neoplasm (four a mucinous cyst, one had intraductal papillary mucinous neoplasm and one a microcystic adenoma) and two had a neuroendocrine tumors (NET) in the head of pancreas. The mean size of the cystic neoplasm and NET were 36.5 mm (SD ± 17.9 mm) and 27.5 mm (SD ± 17.7 mm) respectively. The EUS-RFA was successfully completed in all cases. Among the 6 patients with a cystic neoplasm, post procedure imaging in 3-6 mo showed complete resolution of the cysts in 2 cases, whilst in three more there was a 48.4% reduction [mean pre RF 38.8 mm (SD ± 21.7 mm) vs mean post RF 20 mm (SD ± 17.1 mm)] in size. In regards to the NET patients, there was a change in vascularity and central necrosis after EUS-RFA. No major complications were observed within 48 h of the procedure. Two patients had mild abdominal pain that resolved within 3 d.

CONCLUSION

EUS-RFA of pancreatic neoplasms with a novel monopolar RF probe was well tolerated in all cases. Our preliminary data suggest that the procedure is straightforward and safe. The response ranged from complete resolution to a 50% reduction in size.

Diagnostic and therapeutic role of endoscopy in gastroenteropancreatic neuroendocrine neoplasms

Gastroenteropancreatic neuroendocrine neoplasms have substantially increased over the last decades. Because of the indolent clinical course of the disease even in advance stages and the rise in the incidental diagnosis of small asymptomatic lesions, the prevalence of gastroenteropancreatic neuroendocrine neoplasms is higher than that of pancreatic, gastric and oesophageal adenocarcinomas, making them the second most prevalent cancer type of the gastrointestinal tract. This increase in the overall prevalence of gastroenteropancreatic neuroendocrine neoplasms has been paralleled by a growth in the importance of the endoscopist in the care of these patients, who usually require a multidisciplinary approach. In this manuscript the diagnostic and therapeutic role of endoscopic for gastroenteropancreatic neuroendocrine neoplasms will be reviewed.

Endoscopic ultrasound-guided ethanol ablation therapy for tumors

Endoscopic ultrasonography (EUS) has evolved into a useful therapeutic tool for treating a broad range of tumors since being introduced into clinical practice as a diagnostic modality nearly three decades ago. In particular, EUS-guided fine-needle injection has proven a successful minimally invasive approach for treating benign lesions such as pancreatic cysts, relieving pancreatic pain through celiac plexus neurolysis, and controlling local tumor growth of unresectable malignancies by direct delivery of anti-tumor agents. One such ablative agent, ethanol, is capable of safely ablating solid or cystic lesions in hepatic tissues via percutaneous injection. Recent research and clinical interest has focused on the promise of EUS-guided ethanol ablation as a safe and effective method for treating pancreatic tumor patients with small lesions or who are poor operative candidates. Although it is not likely to replace radical resection of localized lesions or systemic treatment of metastatic tumors in all patients, EUS-guided ablation is an ideal method for patients who refuse or are not eligible for surgery. Moreover, this treatment modality may play an active role in the development of future pancreatic tumor treatments. This article reviews the most recent clinical applications of EUS-guided ethanol ablation in humans for treating pancreatic cystic tumors, pancreatic neuroendocrine tumors, and metastatic lesions.