EUS-guided radiofrequency ablation of small pancreatic adenocarcinoma: a new therapeutic option for patients unfit for surgery

Abstract

Figure 1. CT scan showing a low-density mass at the neck of the pancreas (arrow). Radiofrequency ablation (RFA) is a well-established therapeutic option for ablation of dysplastic and neoplastic tissue by the use of local thermal coagulative necrosis. The percutaneous approach has been shown to be effective and safe, but it is unfeasible in cases of lesions with interposition of organs and/or vessels. For pancreatic lesions, surgery-assisted RFA has been described as an invasive treatment for locally advanced pancreatic adenocarcinoma, with a substantial risk of thermal injuries to major vessels or adjacent structures. EUS-guided RFA is a minimally invasive approach that offers high-quality real-time imaging guidance during selective ablation of pancreatic lesions. It has been shown to be feasible and safe in patients with unresectable pancreatic cancer. In this video (Video 1, available online at www.VideoGIE.org), we present a case of EUS-guided RFA of a resectable small pancreatic adenocarcinoma in a patient unfit for surgery. An 83-year-old patient with an incidental CT finding of a 15-mm solid pancreatic lesion (Fig. 1) underwent contrastenhanced (CE) EUS, which revealed a 15-mm hypoechoic and hypoenhancing lesion of the neck of the pancreas, with irregular borders (Fig. 2A and B). EUS fine-needle biopsy was performed with a 20-gauge fenestrated needle, and the lesion was diagnosed as an adenocarcinoma. Although there was no vascular invasion or distant metastases, the patient was judged unfit for surgery because of multiple severe cardiovascular comorbidities. The patient was then referred for EUS-guided RFA of the lesion. We used a novel EUS-RFA system (STARmed, Seoul, Korea) consisting of a 19-gauge needle electrode (EUSRA, EUS-guided RFA electrode) covered with a sheath, except for the terminal 1 cm with a sharp conical tip for energy delivery, and an RF generator. Furthermore, this system features an internal cooling system that circulates chilled saline solution through the needle electrode during the RFA procedure to prevent charring of the surface of the electrode and to improve the accuracy of the ablation. The lesion was punctured at 2 different points, and 20W ablation power was delivered at both sites under direct EUS control (Fig. 2C). Ablation time was related to tissue impedance measured in real time by the RF generator. Bioimpedance reflects the property of a tissue to conduct electricity. An impedance rise is an indirect sign