Successful Endoscopic Ultrasound-Guided Alcohol Ablation of Sporadic Insulinoma Using Three-Dimensional Targeting (with Video)

A single-center experience on endoscopic ultrasonography-guided ethanol ablation of insulinomas

BACKGROUND/OBJECTIVES

As the most frequent functional pancreatic neuroendocrine tumor, insulinomas may cause a plethora of symptoms and severe impairment in the living of patients by endogenous hyperinsulinemia and subsequent hypoglycemia. Surgery has been regarded as the first choice although a high risk of complications. Ethanol ablation is a promising non-surgical option that could achieve tumor shrinking in a short-term period. But the impact of symptom control and the long-term efficacy lack sufficient and good-quality evidence.

METHODS

A total number of 14 endoscopic ultrasonography-guided ethanol ablations were performed in 9 patients between September 2016 and September 2018 in Peking Union Medical College Hospital. The data were collected and prospectively analyzed.

RESULTS

The follow-up duration ranged from 21 to 1567 days in 9 patients, with a median of 994 days. 4 patients were free from relapse during a median follow-up of 1108 days (range: 994-1567 days). In 5 patients who suffered relapses, the median duration with symptom relief after the first ablation was 128 days (range: 13-393 days). If only repeated ablation was taken into consideration, the median duration with symptom relief was 26 days (range: 1-516 days). No complications happened during the procedures. The severe complication rate after the first ablation was 0.0% (0/9), compared to 7.14% (1/14) if each procedure was counted separately. The only severe complication documented was acute pancreatitis which was completely relieved after symptomatic treatment.

CONCLUSIONS

For patients who are not suitable for surgical resections, endoscopic ultrasonography-guided ethanol ablation of insulinomas could be an effective and safe alternative to relieve symptoms of hypoglycemia.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

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 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.

Treatment of Insulinomas by Laparoscopic Radiofrequency Ablation: Case Reports and Literature Review

Despite its rarity, insulinoma is the most common type of pancreatic endocrine neoplasm, with an occurrence of 1 to 5 per million per year in the population. Surgical resection or enucleation is the first line of curative treatment choice for insulinoma. Eight patients with symptomatic insulinomas treated by radiofrequency ablation have been described since 2009. In the past two years, we treated two patients with symptomatic insulinomas (one in the pancreatic tail and the other in the pancreatic neck) successfully using laparoscopic radiofrequency ablation. Both patients achieved complete elimination without any significant complications. Our study suggests laparoscopic radiofrequency ablation could be developed as a safe and effective alternative treatment to surgery for the patients with insulinomas who refuse or are not eligible for surgery.

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.

Multidisciplinary management of refractory insulinomas

Insulinomas are predominantly benign (~90%), pancreatic neuroendocrine tumours characterized by hyperinsulinaemic hypoglycaemia. They usually present as a small (<2 cm), well-demarcated, solitary nodule that can arise in any part of the organ. Treatment for sporadic insulinomas is generally aimed at curative surgical resection with special consideration in genetic syndromes. Patients with significant hypoglycaemia can pose a difficult management challenge. In isolated cases where the patient is not medically fit for surgery or with metastatic spread, other treatment options are employed. Medical therapy with diazoxide or somatostatin analogues is commonly used first line for symptom control, albeit with variable efficacy. Other medical options are emerging, including newer targeted biological therapies, including everolimus (an mTOR inhibitor), sunitinib (a tyrosine kinase inhibitor) and pasireotide, a multisomatostatin receptor ligand. Pasireotide and everolimus both cause hyperglycaemia by physiological mechanisms synergistic with its antitumour/antiproliferative effects. Minimally invasive treatment modalities such as ethanol ablation are available in selected cases (particularly in patients unfit for surgery), peptide receptor radionuclide therapy (PRRT) can effectively control tumour growth or provide symptomatic benefit in metastatic disease, while cytotoxic chemotherapy can be used in patients with higher-grade tumours. This review considers the developments in the medical and other nonsurgical management options for cases refractory to standard medical management. Early referral to a dedicated neuroendocrine multidisciplinary team is critical considering the array of medical, oncological, interventional radiological and nuclear medical options. We discuss the evolving armamentarium for insulinomas when standard medical therapy fails.

Non-surgical ablative therapies for inoperable benign insulinoma

PURPOSE

Benign insulinoma is the most common functioning neuroendocrine tumor of the pancreas. The gold-standard therapeutic approach for insulinoma is surgery, which allows for tumor removal, histology and immunochemical analyses. If surgery is not feasible, minimally invasive ablative procedures performed by interventional radiology can lead to partial or complete remission of hormone hypersecretion and tumor control in insulinoma patients.

METHODS

We performed a review of existing literature on non-chemotherapeutic/radioactive ablative techniques employed for the treatment of benign, otherwise inoperable, pancreatic insulinoma. For this purpose, feasibility, effectiveness and safety of ablative treatments for pancreatic insulinoma were reviewed from literature data published from 1982 to date.

RESULTS

A total of 44 insulinoma cases treated with non-surgical ablative techniques were desumed, and divided as follows: 7 cases of tumor embolization, 26 ethanol ablations, 7 radiofrequency ablations, 2 high intensity focused ultrasound ablation, 1 irreversible electroporation and 1 percutaneous microwave ablation. Most cases involved single insulinoma, predominantly located in the pancreas head and body. In the majority of patients, ablation was chosen instead of surgery due to severe comorbidities. After an average follow-up of 16 months, the overall success rate of non-surgical ablative treatments of insulinoma was 84%, the recurrence/persistence rate was 16%, and transient adverse events were noted in 23% of cases. Adverse events were usually self-limiting and medically manageable.

CONCLUSIONS

Non-surgical ablation is a feasible, safe and repeatable procedure in patients with pancreatic insulinoma, who are not candidate to surgery or refuse it. Partial or complete control of symptoms and tumor growth is experienced by the majority of patients.