Efficacy and safety of endoscopic ultrasonography-guided radiofrequency ablation of small pancreatic neuroendocrine neoplasms: A prospective, pilot study

Abstract

Objectives

Endoscopic ultrasonography (EUS)-guided radiofrequency ablation has recently been introduced as one of the management strategies for small pancreatic neuroendocrine neoplasms (PNENs). However, prospective data on its safety and efficacy remain limited.

Methods

This prospective pilot study was conducted at Okayama University Hospital from May 2023 to December 2024. Patients with grade 1 PNENs ≤15 mm, confirmed by EUS-guided fine-needle aspiration, were included. The primary endpoint was safety (adverse events [AEs] evaluated according to the 2010 guidelines of the American Society for Gastrointestinal Endoscopy. Severe AEs were defined as moderate or higher in American Society for Gastrointestinal Endoscopy grading and grade ≥3. Secondary endpoints included efficacy (complete response on contrast-enhanced computed tomography at 1 and 6 months), treatment details, device failure, diabetes mellitus exacerbation, and overall survival at 6 months.

Results

Five patients with non-functional PNENs (median age: 64 years; median tumor size: 10 mm) were treated. AEs occurred in two patients (40%, 2/5), although none was severe. Both patients developed asymptomatic pseudocysts, one experienced mild pancreatitis, and both resolved with conservative treatment. The complete response rates on contrast-enhanced computed tomography at one and 6 months were 100%. The median procedure time was 16 min without any device failure, and the median hospitalization was 5 days. None of the patients developed new-onset or worsening diabetes mellitus. The 6-month overall survival rate was 100%.

Conclusion

EUS-guided radiofrequency ablation demonstrated a high complete response rate with no severe AEs in this pilot study, suggesting a minimally invasive option for small, low-grade PNENs (jRCTs062230014).