Letter to the Editor: Beyond cyst size - a time-risk-state framework for dynamic surveillance de-escalation of branch duct intraductal papillary mucinous neoplasms

Table 1 Core differences between the traditional static model and the proposed time-risk-state dynamic framework

Dimension	Traditional static model	Proposed three-dimensional dynamic framework
Risk rating	One-time, fixed; based on baseline cyst morphology	Dynamic, adjustable; redefined after 2 years of stable follow-up
Surveillance intensity	Uniform for all patients (magnetic resonance imaging/endoscopic ultrasound every 6-12 months)	Differentiated by risk: Intensified (0-2 years) → low-frequency (2-5 years) → possible discontinuation (≥ 5 years)
Core decision variables	Cyst size, mural nodules, MPD diameter, CA19-9 level	Three-dimensional: Cyst biology + temporal stability (2-year NPV) + patient status (age and CCI)
Endpoint for discontinuation	“Surveillance until patient unfit for surgery” (passive, vague)	Clear, active thresholds: Stable for ≥ 5 years, age ≥ 75 years or CCI ≥ 3, SIR not significantly different from that of the general population

CA19-9: Carbohydrate antigen 19-9; CCI: Charlson comorbidity index; MPD: Main pancreatic duct diameter; NPV: Negative predictive value; SIR: Standardized incidence ratio.