Endoscopic ultrasound-guided ablation of small pancreatic neuroendocrine neoplasms: Bridging the gap between surveillance and surgery

Table 1 Comparison of endoscopic ultrasound-guided ablative techniques for small pancreatic neuroendocrine neoplasms

Parameter	EUS-guided ethanol injection	EUS-RFA	Emerging EUS-guided techniques
Mechanism of action	Chemical coagulative necrosis through protein denaturation and vascular thrombosis	Thermal coagulative necrosis induced by high-frequency alternating current	Hybrid cryothermal or laser-induced thermal ablation
Technical complexity	Low	Moderate to high	High; experimental
Equipment	Standard 22-gauge or 25-gauge EUS needle	Dedicated needle-based or catheter-based RFA system and generator	Dedicated probes or optical fibers with limited availability
Technical success	Approximately 90%-100%	Approximately 95%-100%	Insufficient panNEN-specific data
Complete radiological response	Approximately 50%-70%; may increase with repeat treatment	Approximately 80%-90%	Unknown
Clinical success in functioning tumors	High, particularly in insulinomas	Very high, generally > 90% in insulinomas	Unknown
Number of sessions	Frequently more than one	Usually, one or two	Not standardized
Main adverse events	Pancreatitis, abdominal pain, ethanol leakage, pancreatic tissue injury	Pancreatitis, abdominal pain, pancreatic duct injury or stenosis	Safety profile not established in panNENs
Main procedural risk factor	Excessive or extratumoral ethanol diffusion	Close proximity to the MPD, particularly ≤ 1 mm	Not defined
Control of ablation volume	Limited and diffusion-dependent	More predictable and energy-controlled	Potentially precise, but not clinically validated
Most established clinical setting	Small insulinomas and selected small NF-panNENs	Small, well-differentiated insulinomas and selected NF-panNENs	Investigational
Main limitation	Unpredictable ethanol distribution and frequent need for repeat treatment	Requirement for dedicated equipment, expertise, and careful ductal assessment	Lack of dedicated clinical evidence in panNENs

EUS: Endoscopic ultrasound; panNENs: Pancreatic neuroendocrine neoplasms; NF-panNENs: Non-functioning pancreatic neuroendocrine neoplasms; EUS-RFA: Endoscopic ultrasound-guided radiofrequency ablation; MPD: Main pancreatic duct.