Radio-frequency ablation for symptom control in a patient with metastatic pancreatic insulinoma

The role of microwave ablation in management of functioning pancreatic neuroendocrine tumors

Background

Surgical resection is considered to be the only potentially curative option for patients with pancreatic neuroendocrine tumors (pNETs). High risk rates of perioperative complications make minimally invasive ablative techniques a novel perspective and alternative treatment option for pancreatic neuroendocrine tumors. This study aims to present the first experience of using a microwave ablation in management of pNETs.

Methods

Sechenov University has an experience of treating more than 400 patients with hormone-producing tumors of the pancreas, 7 of which were treated by microwave ablation (MWA).

Results

In all patients that underwent MWA, a regression of hormonal symptomatic was achieved. Two patients required readmission a month later for draining of pseudocyst and abscess.

Conclusions

The exact role of microwave ablation in the treatment of non-metastatic pancreatic neuroendocrine tumors has not been defined yet. There is a lack of large prospective randomized studies and the reason for this is that local tumor destruction is indicated in selected cases only, thus making it difficult to analyze a large group of patients and assess long-term results of the treatment. However, microwave ablation allows to take a better control of symptoms in patients with hormone overproduction and in those with high risk of postoperative complications.

Radiofrequency ablation for hepatic oligometastatic pancreatic cancer: An analysis of safety and efficacy

OBJECTIVES

This study was to evaluate the value of radiofrequency ablation (RFA) in the treatment of pancreatic cancer with synchronous liver oligometastasis.

METHODS

102 patients diagnosed with pancreatic cancer with synchronous liver oligometastasis undergoing RFA were recruited in this retrospective study between January 2012 and December 2015. Clinical efficacy was evaluated by computed tomography or magnetic resonance imaging 1 month later. All patients were treated with RFA and systemic chemotherapy based on NCCN guideline.

RESULTS

The median follow-up was 21 months (range, 4.0-43.8 months). Of all patients, the 1-year survival rate was 47.1% and the median overall survival time was 11.40 months. Complete tumor ablation was achieved in 137 of 145 RFA sessions (94.5%), and in 244 of 254 tumors (96.1%). The incidence of common complications was 9.8%, and no severe complications were reported in any patient. Multivariate Cox regression analysis revealed that primary tumor in the head of the pancreas (HR = 1.868, 95% CI: 1.023-3.409; P = 0.042), maximum diameter of liver metastasis 3-5 cm (HR = 1.801, 95% CI: 1.081-3.001, P = 0.024) and neutrophil/lymphocyte ratio (NLR) ≥2.5 (HR = 1.716, 95% CI: 1.047-2.811; P = 0.032) were independent predictors of poorer survival.

CONCLUSION

RFA provides a minimally invasive and safe treatment for patients with pancreatic cancer with liver oligometastases. The clinical efficiency of RFA for hepatic oligometastatic pancreatic cancer was easily affected by the following factors: primary tumor location, maximum diameter of liver metastasis and NLR. These factors could be helpful for treatment decision and clinical trial design.

Treatment of symptomatic neuroendocrine tumor syndromes: recent advances and controversies

INTRODUCTION

Neuroendocrine tumors(NETs), once thought rare, are increasing in frequency in most countries and receiving increasing-attention. NETs present two-treatment problems. A proportion is aggressive and a proportion has a functional, hormone-excess-state(F-NET), each of which must be treated. Recently, there have been many advances, well-covered in reviews/consensus papers on imaging-NETs; new, novel anti-tumor treatments and understanding their pathogenesis. However, little attention has been paid to advances in the treatment of the hormone-excess-state. These advances are usually reported in case-series, and case-reports with few large studies. In this paper these advances are reviewed. Areas covered: Advances in the last 5-years are concentrated on, but a review of literature from the last 10-years was performed. PubMed and other databases (Cochrane, etc.) were searched for F-NET-syndromes including carcinoid-syndrome, as well as meeting-abstracts on NETs. All advances that controlled hormone-excess-states or facilitated-control were covered. These include new medical-therapies [serotonin-synthesis inhibitors(telotristat), Pasireotide, new agents for treating ACTHomas], increased dosing with conventional therapies (octreotide-LAR, Lanreotide-Autogel), mTor inhibitors(everolimus), Tyrosine-kinase inhibitors(sunitinib),cytoreductive surgery, liver-directed therapies (embolization, chemoembolization, radioembolization, RFA), peptide radio-receptor-therapy(PRRT) and ¹³¹I-MIBG, ablation of primary F-NETs. Expert opinion: Although many of the newer therapies controlling the hormone-excess-states in F-NETs are reported in relatively few patients, all the approaches show promise. Their description also generates some controversies/unresolved areas,such as the order of these new treatments, their longterm-efficacy, and effectiveness of combinations which may require large,controlled studies.

EUS-guided radiofrequency ablation for management of pancreatic insulinoma by using a novel needle electrode (with videos)

BACKGROUND AND AIMS

Insulinomas are one of the most common functional pancreatic neuroendocrine tumors. Surgical removal is the standard of care. Patients unfit for or refusing surgery need an alternative nonsurgical method to alleviate symptoms. EUS has been used to localize, aspirate, and tattoo insulinomas and to inject alcohol for local ablation. This study is aimed at assessing the feasibility of EUS-guided radiofrequency ablation (EUS-RFA) for managing patients with a symptomatic insulinoma by using a novel EUS-RFA needle electrode.

METHODS

The EUS-RFA system used consists of a prototype 19-gauge needle electrode, generator, and internal cooling system. EUS-guided RFA is performed under real-time visualization at 50 W to ablate pancreatic insulinomas.

RESULTS

In this observational human case series from a tertiary care center, 3 patients with a symptomatic pancreatic insulinoma, not eligible for surgery, underwent EUS-RFA by using an internally cooled prototype needle electrode. All had rapid symptom relief with biochemical improvement and remained symptom free at 11 to 12 months of follow-up. There were no procedure-related adverse events.

CONCLUSIONS

EUS-RFA with the novel device can be considered in select patients with a symptomatic pancreatic insulinoma based on preliminary findings of a beneficial effect without adverse events. Assessment of the safety profile requires larger prospective trials.

Diagnosis and management of insulinoma

Insulinomas, the most common cause of hypoglycemia related to endogenous hyperinsulinism, occur in 1-4 people per million of the general population. Common autonomic symptoms of insulinoma include diaphroresis, tremor, and palpitations, whereas neuroglycopenenic symptoms include confusion, behavioural changes, personality changes, visual disturbances, seizure, and coma. Diagnosis of suspected cases is based on standard endocrine tests, especially the prolonged fasting test. Non-invasive imaging procedures, such as computed tomography and magnetic resonance imaging, are used when a diagnosis of insulinoma has been made to localize the source of pathological insulin secretion. Invasive modalities, such as endoscopic ultrasonography and arterial stimulation venous sampling, are highly accurate in the preoperative localization of insulinomas and have frequently been shown to be superior to non-invasive localization techniques. The range of techniques available for the localization of insulinomas means that blind resection can be avoided. Intraoperative manual palpation of the pancreas by an experienced surgeon and intraoperative ultrasonography are both sensitive methods with which to finalize the location of insulinomas. A high proportion of patients with insulinomas can be cured with surgery. In patients with malignant insulinomas, an aggressive medical approach, including extended pancreatic resection, liver resection, liver transplantation, chemoembolization, or radiofrequency ablation, is recommended to improve both survival and quality of life. In patients with unresectable or uncontrollable insulinomas, such as malignant insulinoma of the pancreas, several techniques should be considered, including administration of ocreotide and/or continuous glucose monitoring, to prevent hypoglycemic episodes and to improve quality of life.

Radiofrequency ablation of liver metastasis in patients with locally controlled pancreatic ductal adenocarcinoma

PURPOSE

To evaluate retrospectively the role of radiofrequency (RF) ablation for liver metastases arising from pancreatic ductal adenocarcinoma simultaneously with pancreatic resection or after curative resection in patient survival.

MATERIALS AND METHODS

RF ablation of liver metastases was performed on 34 patients with pancreatic ductal adenocarcinoma postoperatively after pancreatectomy or intraoperatively at pancreatectomy between December 2002 and June 2009. Criteria for RF ablation were liver metastasis ≤ 3 cm diameter in size, five or fewer lesions, and no definite suspicious lesion other than liver metastasis. Patient survival was assessed by the Kaplan-Meier method, and prognostic factors were analyzed.

RESULTS

Of the patients receiving RF ablation treatment (n = 34), 18 underwent one session of RF ablation, and 16 underwent more than one session. In each session, all the targeted lesions were successfully ablated by ultrasound-guided RF ablation. Median duration of follow-up was 15 months (range, 3-65 mo). The interval between pancreatic resection and liver metastasis was 3 months (range, 0-33 mo). Median survival time after liver metastasis was 14 months. Univariate analysis of factors affecting survival showed that better patient survival after RF ablation was associated with a single, < 2 cm diameter liver metastasis (P = .007) and well or moderate differentiation (P = .032). In multivariate analysis, a single < 2 cm diameter liver metastasis and good or moderate differentiation were independent predictors for longer patient survival (P = .027, P = .016).

CONCLUSIONS

RF ablation in liver metastasis occurring after locally controlled pancreatic ductal adenocarcinoma can be a safe and feasible strategy for extending survival in selected patients.

Interventional endoscopic ultrasonography: present and future

The technical advances in endoscopic ultrasonograpy (EUS) and accessories have enabled performing EUS-guided intervention in the pancreas and biliary tract. Many research centers have been performing or investigating EUS-guided drainage, EUS-guided celiac plexus neurolysis and block, EUS-guided anastomosis that includes choledocho-enterostomy and choledocho-gastrostomy, EUS-guided ablation and injection therapy mainly for pancreatic neoplasm, EUS-guided photodynamic therapy and EUS-guided brachytherapy. Some of these are currently clinical applications and others are under investigations in clinical studies or animal models. Further detailed randomized controlled clinical trials and the development of materials will bring us into a new era of therapeutic EUS.

Interventional endoscopic ultrasonography: present and future

The technical advances in endoscopic ultrasonograpy (EUS) and accessories have enabled performing EUS-guided intervention in the pancreas and biliary tract. Many research centers have been performing or investigating EUS-guided drainage, EUS-guided celiac plexus neurolysis and block, EUS-guided anastomosis that includes choledocho-enterostomy and choledocho-gastrostomy, EUS-guided ablation and injection therapy mainly for pancreatic neoplasm, EUS-guided photodynamic therapy and EUS-guided brachytherapy. Some of these are currently clinical applications and others are under investigations in clinical studies or animal models. Further detailed randomized controlled clinical trials and the development of materials will bring us into a new era of therapeutic EUS.

EUS-Guided Antitumor Therapy for Pancreatic Tumors

Endoscopic ultrasound (EUS) is a very useful modality for the diagnosis and staging of pancreatic masses. With the advent of EUS-guided fine-needle aspiration technology, this modality has made a tremendous leap from imaging modality to histologic diagnosis and therapeutic intervention. EUS offers high-resolution images of and unparalleled access to the pancreas. After locating the tip of the echoendoscope in the duodenum or stomach, several drugs or local treatment modalities can be delivered directly into the pancreas. EUS-guided ethanol lavage with/without paclitaxel injection has been tested for the treatment of cystic tumors of the pancreas, with complete resolution of cystic tumor being observed in up to 70-80% of patients. Ethanol injection is also performed for the management of solid neuroendocrine tumors of the pancreas. Various type of EUS-guided injection have also been investigated for the treatment of pancreatic cancer. An activated allogenic mixed lymphocyte culture (Cytoimplant) was injected in patients with advanced pancreatic cancer. A replication-deficient adenovirus vector carrying the tumor necrosis factor-alpha gene was also delivered intratumorally by EUS. ONYX-015 is an oncolytic attenuated adenovirus that exhibits replication preferentially in malignant cells, causing cell death, and this has also been injected into pancreatic cancers under EUS guidance. EUS-guided local ablation therapies such as radiofrequency ablation, photodynamic therapy, and brachytherapy are also under investigation. EUS-guided fine-needle injection for various solid or cystic lesions is a rapidly expanding field. This article reviews the various applications of EUS for the treatment of pancreatic tumors.

High intensity focused ultrasound ablation of pancreatic neuroendocrine tumours: report of two cases

We describe the use of ultrasound-guided high-intensity focused ultrasound (HIFU) for ablation of two pancreatic neuroendocrine tumours (NETs; insulinomas) in two inoperable young female patients. Both suffered from episodes of severe nightly hypoglycemia that was not efficiently controlled by medical treatment. After HIFU ablation, local disease control and symptom relief were achieved without postinterventional complications. The patients remained free of symptoms during 9-month follow-up. The lesions appeared to be decreased in volume, and there was decreased enhancing pattern in the multidetector computed tomography control (MDCT). HIFU is likely to be a valid alternative for symptoms control in patients with pancreatic NETs. However, currently the procedure should be reserved for inoperable patients for whom symptoms cannot be controlled by medical therapy.

Radiofrequency ablation of solitary pancreatic insulinoma in a patient with episodes of severe hypoglycemia

Insulinomas are rare neuroendocrine tumors of the pancreas. Therapy of first choice is the surgical resection or enucleation. In cases of metastases or in patients with high surgical risk, medical therapy with diazoxide or octreotide is an alternative. In this case, we describe the successful use of computed tomography (CT)-guided radiofrequency ablation (RFA) of an insulinoma in an 80-year-old female patient. The patient suffered from episodes of severe nightly hypoglycemia with a minimal glucose concentration of 1.95 mmol/l (36 mg/dl). An insulinoma measuring 1.5 cm in diameter was localized by endoscopic ultrasound and CT scan in the tail of the pancreas. Owing to a high surgical risk caused by the patient's comorbidities and poor physical condition, the resection of the tumor was not considered. The medical treatment with diazoxide failed to control the symptoms of hypoglycemia sufficiently. Using CT-guided percutaneous RFA, the insulinoma was successfully ablated. No postinterventional complications occurred. During a 5-week follow-up, episodes of hypoglycemia were absent. A control-CT, 5 weeks after RFA, revealed no residual tumor. In conclusion, we found RFA suitable for the treatment of pancreatic insulinomas. Until more data concerning efficacy and complication rates have been collected; the procedure should be reserved for the treatment of patients who are no candidates for surgical therapy and in whom symptoms cannot be controlled by the medical therapy.

Current medical treatment of pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (NETs) consist of a wide group of neoplasms, with different biological behaviors in terms of aggressiveness and hormone production. In the last two decades, significant progress has been observed in our understanding of their biology, diagnosis and treatment. Surgery remains to be the only curative approach, but unfortunately the diagnosis is often delayed due to the slow growth of these tumors and the difficulty in identifying the symptoms related to the tumor-released hormones. In addition to surgery, other approaches to control the disease are biological therapy consisting of somatostatin analogs and interferon (IFN), systemic chemotherapy, radioligand therapy and local therapy with chemoembolization. Several newer cytotoxic agents, including irinotecan, gemcitabine, taxanes, oxaliplatin, capecitabine and PS-341 have been studied in metastatic patients. Considering the high vascularity of these tumors, antiangiogenic agents like endostatin and thalidomide have also been evaluated in advanced NETs. Although these agents seem to have potential activity in NETs and may increase progression free survival, none of these currently available medical therapeutic options are curative. While more efficient novel strategies are to be developed, the rationale use of the current therapeutic options may improve quality of life, control the symptoms related to the hypersecretion of hormones and/or peptides, control tumor proliferation and prolong survival in patients suffering from NETs.

EUS-guided alcohol ablation of an insulinoma

BACKGROUND

Surgical resection is currently considered to be the criterion standard for treatment of insulinomas. Alternative treatments, despite medication with diazoxide, are lacking. EUS-guided ethanol ablation of endocrine tumors has not been reported before.

INTERVENTION

A 78-year-old woman was referred with typical symptoms of an insulinoma. Diagnosis was confirmed by laboratory findings, EUS, and EUS-guided FNA. Because of severe complications during several hypoglycemic episodes, a poor general condition, and strict refusal of surgical resection, the decision was made to ablate the insulinoma by EUS-guided alcohol injection. A total of 8 mL 95% ethanol was injected into the tumor.

RESULTS

The patient was discharged and exhibited no further hypoglycemic episodes, and her general condition improved rapidly. Based on clinical, morphologic, and biochemical criteria, we achieved a durable complete remission of the tumor.

CONCLUSIONS

EUS-guided ablation may become a minimally invasive alternative for patients with insulinomas in whom surgery is not feasible.

Radiofrequency ablation has a valuable therapeutic role in metastatic VIPoma

BACKGROUND

Vasoactive intestinal peptide-secreting tumours (VIPomas) are rare islet cell tumours of the pancreas that can result in life-threatening biochemical abnormalities. The optimal intervention for metastatic VIPoma remains undecided. This case history documents the clinical role of radiofrequency (RF) ablation in the treatment of metastatic VIPoma.

CASE HISTORY

A primary pancreatic VIPoma was diagnosed in a 61-year-old female in 1998 and a distal pancreatectomy and splenectomy were performed. She remained disease-free for 44 months when she presented as an emergency with watery diarrhoea, hypokalaemia, renal failure and an elevated serum VIP level. CT scanning showed a liver metastasis and open RF ablation was performed with complete resolution of symptoms and biochemistry within 48 h. Post-ablation imaging confirmed complete ablation of the metastasis. She remained disease-free until 22 months later when watery diarrhoea resumed and a new hepatic metastasis was seen on CT. Percutaneous RF ablation was performed and follow-up CT scan showed complete ablation of the metastasis. The patient remains disease- and symptom-free 10 months after the second RF ablation.

CONCLUSION

This case illustrates that the pronounced clinical and biochemical upset caused by metastatic VIPoma can be resolved safely, quickly and repeatedly by RF ablation.

Malignant metastatic insulinoma-postoperative treatment and follow-up

The rarity of malignant insulinoma limits reports on therapeutic strategies and outcome. The treatment and follow-up of 10 patients, all presenting an insulinoma with metastatic disease of the liver and newly diagnosed between 1992 and 2002, is reported. Pancreatic surgery with successful removal of the primary tumor preferentially located in the tail was performed in 7 women and 3 men, median age 55 years (range 36-82 years). If appropriate, 5 patients underwent additional hepatic surgery and lymph node resections. Liver metastases as the major cause of postoperatively persistent hypoglycemia were subsequently treated by repeated transarterial hepatic chemoembolization and chemoperfusion protocols using high-dose transhepatic streptozocin perfusions (3-4 g per session). The current median survival time for all 10 patients is 2.6 years (range: 1.6-9.7 years). Six patients are currently alive with a median survival of 3.7 years (1.7-9.7 years), five of them with stable disease and free of hypoglycemia. Four patients died after a median survival of 1.8 years (range: 1.6-7.5 years) from complications of unmanageable hypoglycemia. It is concluded that the necessity to treat debiliating and life-threatening hypoglycemia in metastatic malignant insulinoma warrants the option of radical endocrine surgery in combination with extended and repeated postoperative chemoembolization of liver metastases.

Malignant insulinoma: spectrum of unusual clinical features

BACKGROUND

Malignant insulinoma occurs in a few patients with insulinoma. Due to the small sample of patients, there are little data regarding their clinical manifestation as well as the preferred treatment modalities. The aims of the current study were to summarize the National Institutes of Health experience during the last two decades and to conduct a critical review of the current literature.

METHODS

The authors identified 10 patients with metastatic insulinoma.

RESULTS

The patients presented with four patterns of clinical behavior. First, four patients presented with lymph node metastasis and, after surgical excision, maintained a prolonged tumor-free survival. Second, four patients presented with metastatic disease to the liver, which appeared years after the initial diagnosis and presumed curative surgery. Third, one patient presented with a large alpha-fetoprotein-secreting liver mass. Finally, 9 of the 10 patients had a prolonged survival. Various treatment modalities were used to control hypoglycemia. Short-term benefits were most often achieved with embolization and diazoxide. Less successful modalities included radiofrequency ablation, radical debulking surgery, verapamil therapy, octreotide therapy, and chemotherapy.

CONCLUSIONS

The current study, as well as others, suggested that metastatic insulinoma may have a variable natural history. After the initial surgical resection, the biology of the tumor, rather than any treatment modality, was most likely the major determinant of long-term survival.