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

Table 2 Proposed criteria for patient selection for endoscopic ultrasound-guided ablative treatment in small pancreatic neuroendocrine neoplasms

Parameter	More favorable candidate	Borderline candidate (case-by-case)	Generally unsuitable candidate
Tumor size	≤ 15 mm	15-20 mm	> 20 mm
Differentiation	Well-differentiated NET	Well-differentiated NET	Poorly differentiated NEC
Tumor grade	G1, Ki-67 < 3%	Selected low-G2 tumor (Ki-67 ≤ 5%), after multidisciplinary review	G3 or clearly high-proliferative G2 tumor
Functionality	Insulinoma	Other functioning tumors are considered only for symptom control in exceptional circumstances	Functioning tumor with multifocal, nodal, or metastatic disease
Nodal or distant disease	Absent	Indeterminate findings requiring further staging	Present
Behavior during surveillance	No clear evidence of aggressive behavior	Limited interval growth requiring repeat staging and reassessment	Rapid growth or other evidence of progression
Tumor margins and local invasion	Well-defined, confined lesion	Uncertain local relationships	Vascular invasion, perineural invasion, or infiltrative margins
EUS accessibility	Safe and straightforward access	Technically feasible but challenging	Unsafe or impossible access
Relationship with MPD	Clear separation from the duct	Close proximity requiring increased caution	Direct contact, duct involvement, or inability to preserve a safe margin
Pancreatic duct dilation	Absent	Equivocal or unrelated dilation requiring clarification	Dilation attributable to tumor obstruction
NF-panNENs	Active treatment considered appropriate despite disproportionate surgical morbidity	Uncertain balance between surveillance, ablation, and surgery	Stable low-risk lesion appropriately managed by surveillance
Surgical risk	High surgical risk or relevant comorbidities	Intermediate risk	Fit patient with a clear surgical indication
Patient preference	Declines surgery after informed counseling	Preference uncertain or evolving	Prefers surgery or does not accept structured follow-up
Treatment setting	Expert tertiary center with multidisciplinary NET expertise	Expert center after extended multidisciplinary discussion	Center without advanced EUS and pancreatic support
Post-treatment surveillance	Accepts structured long-term follow-up	Potential concerns regarding adherence	Unable or unwilling to undergo surveillance

This framework reflects the authors’ interpretation of the available evidence and should not be regarded as a validated guideline. Eligibility should be determined within an experienced multidisciplinary team. EUS: Endoscopic ultrasound; NF-panNENs: Non-functioning pancreatic neuroendocrine neoplasms; NET: Neuroendocrine tumour; NEC: Neuroendocrine carcinoma; MPD: Main pancreatic duct.