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

Abstract

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.

Local ablation of pancreatic tumors: State of the art and future perspectives

“…In particular, RFA treatment should be avoided when the target is near large vessels because of the heat sink effect[ 19 ]. However, the bipolar system of RFA can reduce the heat sink effect and lower pancreatic injury[ 10 ].…”

Role of Radiofrequency Ablation in the Management of Unresectable Pancreatic Cancer

“…RFA poses a risk of potential adverse events both to surrounding vital structures as well as pancreas itself. Common potential adverse events associated with RFA therapy are acute pancreatitis, pancreatic fistula, gastrointestinal hemorrhage, sepsis, portal vein thrombosis, and damage to surrounding structures, such as duodenum or bile duct ( 19 ). However, the risk of these adverse events is low with modifications of RFA techniques, such as altering ablation parameters like ablation temperature, distance of RFA needle from adjoining structures, and introducing other safety measures like duodenal and inferior vena cava cooling during ablation ( 20 – 22 ).…”

“…Application of RFA may cause visual obscurities, therefore, it is advisable to ablate the technically challenging part of the tumor first ( 45 ). The recommended thermal energy for effective tumor ablation ranges from 60 to 100°C as temperature >100 may result in a higher risk of adverse events due to damage to surrounding structures ( 19 ). In addition to fragile pancreatic parenchyma that can be damaged by high temperatures, several anatomic challenges may hinder the use of RFA in the treatment of pancreatic cancer.…”

Controversies in EUS: Do we need miniprobes?

“…[ 3 4 ] An additional paper was dealing with ultrasound-guided thermal ablation treatment for pancreatic cancer. [ 5 ] Herewith, the demand for miniprobes in clinical endosonography is controversially discussed.…”