Endoscopic ultrasound-guided radiofrequency ablation for pancreatic neuroendocrine tumors and pancreatic cystic neoplasms: a prospective multicenter study.

Background: Pancreatic neuroendocrine tumors (NETs) and intraductal pancreatic mucinous neoplasia (IPMN) with worrisome features are surgically managed. Endoscopic ultrasound (EUS)-guided radiofrequency ablation (RFA) has recently been developed. The safety of EUS-RFA was the primary end point of this study, its efficacy the secondary end point.

Methods: This was a prospective multicenter study that was planned to include 30 patients with a 1-year follow-up with either a NET < 2 cm or a pancreatic cystic neoplasm (PCN), either a branch duct IPMN with worrisome features or a mucinous cystadenoma (MCA). EUS-RFA was performed with an 18G RFA cooling needle.

Results: 12 patients had 14 NETs (mean size 13.1 mm, range 10 - 20 mm); 17 patients had cystic tumors (16 IPMNs, 1 MCA; mean size 28 mm, range 9 - 60 mm). Overall three adverse events occurred (10 %), two of these in the first two patients (one pancreatitis, one small-bowel perforation). After these initial patients, modifications in the protocol resulted in a decrease in complications (3.5 %), with one patient having a pancreatic ductal stenosis. Among the 14 NETs, at 1-year follow-up 12 had completely disappeared (86 % tumor resolution), with three patients having a delayed response. Among the 17 PCNs, at 12 months, there were 11 complete disappearances and one diameter that decreased by > 50 % (significant response rate 71 %). All 12 mural nodules showed complete resolution.

Conclusions: EUS-RFA of pancreatic NETs or PCNs is safe with a 10 % complication rate, which can be decreased by improved prophylaxis for the procedure.