Efficacy and Safety of Radiofrequency Ablation Under Endoscopic Ultrasonography Guidance in Pancreatic Neuroendocrine and Cystic Tumor

Advances in conventional imaging (abdominal ultrasound, CT scan, MRI) are so great that chance to discover a incidental solid or cystic pancreatic lesion is becoming usual. Endocrine tumors have variable malignant potential depending on their size, some malignancy for lesions larger than 2 cm and indefinite for a smaller size. The branch-duct like IPMN (intraductal papillary mucinous pancreatic tumor) involving the pancreatic secondary ducts represent half of pancreatic cystic tumors and may degenerate into 5 to 10% of cases. Signs and risk of degeneration are the presence of mural nodules greater than 5 mm and size > 3 cm, although the latter criterion is discussed. Mucinous cystadenomas could degenerate between 30 and 50% of cases even though the role of size is much discussed (<4 cm). The follow-up imaging is performed using MRI and endoscopic ultrasonography (EUS). A fine needle aspiration for cytology and histology is possible and determination of biological markers is useful. But cytology is often unprofitable due to the poor cellular profile of the cystic pancreatic tumor. Once the diagnosis of suspected malignancy, the patient should be referred to the surgeon for pancreatic resection more or less extensive. But this attitude is facing a significant operative risk with up to 30% of morbidity and mortality between 1 and 3 % for cephalic resections. Some patients with high post operative risks are inoperable. For these reasons, some teams have proposed the destruction of the walls of the cyst under EUS, US or CT control by washing with absolute alcohol content of cystic tumor.

An interesting alternative endoscopic destruction would be the use of radio frequency ablation technique (RFA). RFA is a recognized technique for local tumor destruction by delivering thermal energy to obtain coagulation necrosis of the lesion. Taewong Medical ™ recently developed a radiofrequency needle EUSRA® coupled with a combo VIVA ™ generator for applying RFA sub EUS control. But no prospective study is available at this date regarding the treatment of the cystic or solid tumoral pancreatic lesion with this technique. The primary endpoint of the present study is to investigate the feasibility and safety of this guided radiofrequency probe EUS for the treatment of pancreatic endocrine tumors or inoperable pancreatic cystic tumors. The secondary objective will be the efficiency.