51 - Safety and Efficacy of Endoscopic Ultrasound-Guided Radiofrequency Ablation for Branch Duct-Intraductal Papillary Mucinous Neoplasms: A Single Arm Clinical Trial

Award: ACG Governors Award for Excellence in Clinical Research (Trainee)

Vanisha Patel, MD¹, Zarine K. Shah, MD¹, Phil Hart, MD¹, Stacey Culp, PhD², Hamza Shah, MD¹, Raj Shah, MD¹, Jordan Burlen, MD¹, Peter J Lee, MD¹, Georgios Papachristou, MD, PhD¹, Somashekar G Krishna, MD^1
1The Ohio State University Wexner Medical Center, Columbus, OH; ²Ohio State University, Columbus, OH

Introduction: Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) is a novel, non-surgical approach for treating pancreatic lesions in patients with high-surgical risk. This trial aims to evaluate the safety and efficacy of EUS-RFA for the thermal ablation of branch duct-intraductal papillary mucinous neoplasms (BD-IPMN).

Methods: Non-operative patients with BD-IPMNs meeting surgical resection criteria underwent EUS-RFA in a single-arm trial (NCT05961982). EUS-guided confocal endomicroscopy and cyst fluid next-generation sequencing (NGS) were used for diagnosis and risk stratification. EUS-RFA was performed with a 19G needle (TaeWoong Medical USA) in Continuance Mode on the VIVA™ Combo System (STARMed, South Korea) applying 50W energy doses until ablation completion. Pre- and post-RFA cyst volume estimates with magnetic resonance imaging and NGS fluid mutation changes were analyzed to identify predictors of volume change.

Results: Twenty-three participants (mean age 75±7 years; 6 female) with 27 BD-IPMNs (mean diameter 4.6±1.7 cm) underwent EUS-RFA. Each BD-IPMN received a median of 16 applications during one session of EUS-RFA. Five participants received a second EUS-RFA treatment at 3-6 months following index treatment.

Post EUS-RFA follow-up was available for 18 BD-IPMNs (n=16 patients) over a mean duration of 6±4 months. A median volume reduction of 70% (23.2 ml to 3.9 ml; p< 0.001) was observed. Complete ablation occurred in 17% (n=3) and more than 50% volume reduction in 78% (n=14). BD-IPMN location in the head/uncinate (p=0.02) and lack of main duct dilation (p=0.04) were significantly associated with post-RFA percentage decrease in volume.

Follow-up cyst fluid NGS demonstrated an absence of KRAS/GNAS mutations in 33% (n=4/12). In 12 participants, a 72% mean decrease in KRAS variant allele fraction (mean of 23.3±17.0% to 6.5±21.3%, p=0.03) was noted.

Adverse events occurred in 9% of EUS-RFA sessions involving 3 participants. These events included bleeding, duodenal and biliary stricture, acute pancreatitis, and duodenal perforation; all were successfully managed.

Discussion: This first prospective trial of EUS-RFA for BD-IPMNs demonstrates a high proportion of clinically significant responses in cyst volume and KRAS mutation burden with acceptable morbidity in a high-risk patient population. Ongoing work is needed to determine the most appropriate measures of treatment efficacy and durability of response.



Disclosures:


Vanisha Patel, MD¹, Zarine K. Shah, MD¹, Phil Hart, MD¹, Stacey Culp, PhD², Hamza Shah, MD¹, Raj Shah, MD¹, Jordan Burlen, MD¹, Peter J Lee, MD¹, Georgios Papachristou, MD, PhD¹, Somashekar G Krishna, MD¹, 51, Safety and Efficacy of Endoscopic Ultrasound-Guided Radiofrequency Ablation for Branch Duct-Intraductal Papillary Mucinous Neoplasms: A Single Arm Clinical Trial, ACG 2024 Annual Scientific Meeting Abstracts. Philadelphia, PA: American College of Gastroenterology.