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

Abstract

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.

Efficacy of EUS-RFA in pancreatic tumors: Is it ready for prime time? A systematic review and meta-analysis

“…electrical impedance of > 500 Ohms is detected, suggesting that coagulative necrosis has occurred within the lesion [1]. This is confirmed by postoperative imaging with a computed tomography (CT) scan.…”

“…Delayed AEs (> 7 days) were reported in two studies including three patients [1,11]. In the Oleinokov study, two patients developed mild pancreatitis between 7 and 10 days post-procedure, which resolved on the second or third day of the hospitalization.…”

“…Of these, six studies showed 100 % pooled clinical success rates with the remaining four reporting clinical success rates ranging from 70 % to 83 %. Many noted a sustained linear regression of the tumor with time when comparing CTs from 7 days post-procedure to CTs at 30 days post-procedure [1,3,10,11]. No significant correlation was found between ablation time, radiofrequency strength, and sustained reduction in tumor burden.…”

“…Use of EUS-RFA in the pancreas also extends to treatment and ablation of small pancreatic neuroendocrine tumors (PNETs), pancreatic cystic neoplasms (PCN) which include mucinous pancreatic cystic neoplasms (MCN), and intraductal papillary mucinous neoplasms (IPMN) and other pancreatic tumors measuring < 3 cm [1].…”

Neuroendocrine Neoplasms of the Small Bowel and Pancreas

“…Conservative management of MEN1-associated non-functioning PanNEN ≤2 cm may be associated with low disease-specific mortality [186], whereas this is inappropriate in tumours 3 cm or larger [187]. Endoscopic ablative technologies may also be utilised in PanNEN patients that would be poor candidates for surgery, or where extensive resection is not desired [188].…”