Clinical efficacy and safety of endoscopic ultrasound-guided ablation therapies for pancreatic neuroendocrine tumors: a systematic review and meta-analysis.

Background: Pancreatic neuroendocrine tumors (pNETs) are rare; however, they are increasingly being detected. Although surgical resection remains the standard treatment, its invasiveness has prompted interest in less invasive alternatives, particularly for small non-functional pNETs (NF-pNETs) and insulinomas. Objectives: To evaluate the clinical efficacy and safety of endoscopic ultrasound-guided ethanol injection (EUS-EI) and radiofrequency ablation (EUS-RFA) for pNETs. Design: A systematic review and meta-analysis. Data sources and methods: A literature search of PubMed, MEDLINE, and Google Scholar was conducted (April 2005-April 2025). Studies were eligible if they reported clinical outcomes of EUS-EI or EUS-RFA in adult patients with insulinomas or NF-pNETs. The primary endpoints were clinical success (short-term symptom resolution or radiological response) and adverse event (AE) rates. Data were pooled using a random-effects model. Results: Twenty-six studies were included in the meta-analysis. For insulinomas, the pooled clinical success rate was 77% (95% confidence interval (CI), 59-88) for EUS-EI and 95% (95% CI, 89-97) for EUS-RFA. The pooled incidence of total AEs was 32% (95% CI, 17-51) for EUS-EI and 25% (95% CI, 15-39) for EUS-RFA. For NF-pNETs, the pooled clinical success rates were 76% (95% CI, 54-90) for EUS-EI and 85% (95% CI, 74-92) for EUS-RFA, and the pooled incidence of total AEs was 27% (95% CI, 20-35) and 26% (95% CI, 17-38), respectively. The most common moderate or severe AEs were pancreatitis in 12 patients (7.6%) after EUS-EI, and pancreatic fluid collection in 4 patients (1.9%) and pancreatic duct stricture in 3 patients (1.4%) after EUS-RFA. One fatal case occurred in a 97-year-old patient following EUS-RFA. Conclusion: Both EUS-EI and EUS-RFA are effective, relatively safe, and minimally invasive treatment options for pNETs. However, severe AE can occur, and careful patient selection and treatment indication are essential. Trial registration: Not registered.