Review of endoscopic radiofrequency in biliopancreatic tumours with emphasis on clinical benefits, controversies and safety

Abstract

Most pancreatic cancers and extrahepatic cholangiocarcinomas are unresectable at the time of diagnosis, and even in case of a resectable cancer, for elderly or patients with coexistent comorbidities, surgery is not an option. Current treatment alternatives in these scenarios are very limited. Biliary stenting with self-expanding metal stents (SEMS) is the mainstay palliative treatment of biliary obstruction due to unresectable pancreatic cancer or cholangiocarcinoma. Nevertheless, more than 50% of SEMS become occluded after 6 mo due to tumour over- and ingrowth, leading to hospital readmissions and reinterventions that significantly impair quality of life. Regimes of chemotherapy or chemoradiotherapy also provide minimal survival benefits. Therefore, novel therapies are eagerly awaited. Radiofrequency (RF) energy causes coagulative necrosis leading to local destruction of the accessed malignant tissue and has an established role in the treatment of malignancies in several solid organs, especially liver cancers. However, pancreatic and extrahepatic biliary cancers are not easily accessed by a percutaneous route, making the procedure dangerous. Over the past five years, the development of dedicated devices compatible with endoscopic instruments has offered a minimally invasive option for RF energy delivery in biliopancreatic cancers. Emerging experience with endoscopic RF ablation (RFA) in this setting has been reported in the literature, but little is known about its feasibility, efficacy and safety. A literature review makes it clear that RFA in biliopancreatic tumours is feasible with high rates of technical success and acceptable safety profile. Although available data suggest a benefit of survival with RFA, there is not enough evidence to draw a firm conclusion about its efficacy. For this reason, prospective randomized trials comparing RFA with standard palliative treatments with quality-of-life and survival endpoints are required. Anecdotal reports have also highlighted a potential curative role of RFA in small pancreatic tumours and benign conditions, such as ductal extension of ampullomas, intrahepatic adenomas or non-tumoural biliary strictures. These newest indications also deserve further examination in larger series of studies.

Novel temperature-controlled RFA probe for treatment of blocked metal biliary stents in patients with pancreaticobiliary cancers: initial experience

“…RFA creates an electrical circuit by using an alternating current which causes protein denaturation and coagulative necrosis. Because of the poor electrical conductivity of tissues, the closest areas to the electrode experience the highest current and temperature, whereas tissues farther away are heated by thermal conduction (i. e., in these regions, the heat may not be sufficiently high to cause necrosis) 11 12 13 . Therefore, a key limitation is the extent of coagulation produced by RFA, which is often insufficient to cover the tumor volume.…”

Therapy of Pancreatic Neuroendocrine Tumors: Fine Needle Intervention including Ethanol and Radiofrequency Ablation

“…The overall clinical experience with EUS-guided RFA for PNETs is limited. In a recent review by Alvarez-Sánchez et al, a total of 42 patients from several case series were reported to have undergone EUS-guided RFA for a variety of pancreatic lesions [ 8 - 10 , 25 - 29 ]. Out of these, 7 patients had PNETs ( Table 2 ).…”

“…However, the same has not been observed for transmural EUS-guided RFA in the pancreas, in the absence of an internal cooling mechanism [ 33 ]. In patients undergoing EUS-guided RFA for non-PNET lesions, mild early complications have been observed, which include mild abdominal pain, mild acute pancreatitis, duodenal bleed treated endoscopically without any blood transfusion, or asymptomatic peri-pancreatic fluid collection [ 25 ].…”

EUS-guided solid pancreatic tumor ablation

“…[ 11 12 13 ] These evaluations provided the initial information to be considered for the EUS-RFA settings used in patients with pancreatic lesions. Recently, Alvarez-Sánchez and Napoléon[ 14 ] reviewed the published data of EUS-RFA; they analyzed seven case series that included a total of 42 patients with different indications treated with different systems.…”