Feasibility and safety of EUS-guided cryothermal ablation in patients with locally advanced pancreatic cancer

Background: New therapies are needed for pancreatic cancer. Objective: To determine the feasibility and safety of a new endoscopic treatment. Secondary endpoints were to determine effects on tumor growth measured with CT scan and to find the overall survival. Design: A cohort study of patients with local progression of advanced pancreatic adenocarcinoma after neoadjuvant therapy. The cryotherm probe (CTP), a flexible bipolar device that combines radiofrequency with cryogenic cooling, was used under EUS guidance. Setting: San Raffaele Hospital, Milan, Italy; University Medical Center, Hamburg-Eppendorf, Germany. Patients: A total of 22 patients (male/female 11/11; mean age 61.9 years) were enrolled from September 2009 to May 2011. Intervention: Radiofrequency heating: 18 W; pressure for cooling: 650 psi (Pounds per Square Inch); application time: depending on tumor size. Main Outcome Measurements: Feasibility was evaluated during the procedure. A clinical and radiologic follow-up was planned. Results: The CTP was successfully applied in 16 patients (72.8%); in 6 it was not possible because of stiffness of the GI wall and of the tumor. Amylase arose in 3 of 16 patients; none had clinical signs of pancreatitis. Late complications arose in 4 cases: 3 were mostly related to tumor progression. Median postablation survival time was 6 months. A CT scan was performed in all patients, but only in 6 of 16 was it possible to clearly define the tumor margins after ablation. In these patients, the tumor appeared smaller compared with the initial mass (P =.07). Limitations: Small sample of patients, difficulty of objectifying the size of the ablated zone by CT scan. Conclusion: EUS-guided CTP ablation is feasible and safe. Further investigations are needed to demonstrate progression-free survival and local control.