EUS-Guided Radiofrequency Ablation for the Management of Pancreatic Tumors

Abstract

Endoscopic ultrasound (EUS) became an indispensable tool not only for the diagnosis but also for the management of pancreatic tumors. With the modification of EUS-guided fine needle aspiration (EUS-FNA) technology, EUS-guided fine needle injection (EUS-FNI), EUS-guided ablation and other interventions can be applied for various solid or cystic lesions in the pancreas. Local ablative modalities such as radiofrequency ablation (RFA) or photodynamic therapy (PDT) are also applied to pancreas in animal studies. RFA is primarily delivered to liver percutaneously or intraoperatively. EUS-guided RFA in a pig model proved that this modality can also be delivered to the pancreas trans-gastrically and cause well-demarcated coagulation zone. This modality, however, should be improved and refined to reduce the possible complications such as pancreatitis, gastric burn or perforation. Our group conducted EUS-guide RFA human trial for unresectable pancreatic cancer and showed technical feasibility and safety of EUS-RFA for pancreatic cancer. Further studies are required to see the long-term efficacy and survival benefit of this adjunctive modality for pancreatic cancer. EUS-RFA can be applied for the management of small pancreatic or peripancreatic tumors such as neuroendocrine tumor, adrenal tumor and small lymph node metastasis. Initial studies using EUS-RFA for the treatment of pancreatic neuroendocrine tumor showed very promising result without any serious complication. EUS-RFA seems to be very useful especially for the management of insulinoma. Since the patient presents with recurrent hypoglycemic attack, insulinoma is generally small in size at the time of diagnosis. It can be easily ablated under EUS-RFA and the functionality can be controlled very effectively. EUS-RFA is also applied for the management of cystic tumor of the pancreas. However, only animal study are reported using GB and cystic duct of pig and more studies are required before direct human application. In conclusion, EUS-guided approach offers minimally invasive access for delivery of local ablation modalities including EUS-RFA. This area is a continuously evolving field and many studies are currently undergoing. Although many of these approaches are still investigational but will play a key role in the treatment of benign and malignant pancreatic disease in the future.