Efficacy and Safety of Endoscopic Ultrasonography-Guided Ethanol Injections of Small Pancreatic Neuroendocrine Neoplasms: a prospective, multicenter study.

Background And Study Aims: Endoscopic ultrasonography (EUS)-guided ethanol injection (EI) has recently been introduced as one of the management strategies for pancreatic neuroendocrine neoplasms (PNENs). However, its role as a surgical alternative is unclear. We evaluated the efficacy and safety of EUS-EI in treating small PNENs through a prospective multicentre study.

Patients And Methods: Patients with Grade 1 tumours of ≤15 mm confirmed by pathology were included. The primary endpoint assessed efficacy and safety, measuring complete ablation using computed tomography at 1 and 6 months, prevention of adverse events (AEs) within 1 month, severe pancreatic fistula at 1 month, and diabetes mellitus (DM) incidence/worsening at 6 months. The composite endpoint of EUS-EI was compared with that of historical results of a study based on surgical treatment.

Results: Twenty-five patients with PNENs, with a median tumour size of 10.1 mm, were treated using EUS-EI. Seventy-six percent of the patients achieved the composite primary endpoint (19/25) (95% confidence interval [CI]=54.9%-90.6%), a proportion significantly higher than that of surgical treatment (P=0.0083). Regarding efficacy, 88% (22/25) of the patients achieved complete ablation at 1 and 6 months (95% CI=68.8%-97.5%). Regarding safety, 96% (24/25) of the patients had no severe AEs within 1 month (95% CI=79.7%-99.9%). No patients had severe pancreatic fistulas at 1 month, and 84% (21/25) of the patients had no incidence or exacerbation, or both, of DM at 6 months (95% CI=63.9%-95.5%).

Conclusion: EUS-EI is safe and could be a potent treatment option for patients with small PNENs.