Table 2.

Different surveillance strategies according to International, European and American Gastroenterological Association (AGA) guidelines.

Guideline	Year	Indications for surveillance	Methods of follow-up	Timing
IAP I27	2006	BD-IPMNs ≤30 mm without: – symptoms – mural nodules – positive cytology	MRI/MRCP or CT scan	Cyst size ≤20 mm: • Every 6–12 monthsa Cyst size 20–30 mm: • Every 3–6 months Lifetime surveillance ^ The interval of follow-up can be lengthened after 2 years of no change
AGA8	2015	BD-IPMNs ≤30 mm without: – solid component – dilated MPD – HGD or cancer on cytology	MRI	Years 1, 2, 5 from initial diagnosis If no significant change occurs, consider surveillance discontinuation
IAP III6,b	2017	No high-risk stigmata or worrisome features Cyst size <10 mm	(CT scan) MRI/MRCP	• At 6 months from diagnosis • Every 2 years (if no change)
		No high-risk stigmata or worrisome features Cyst size 10–20 mm	(CT scan) MRI/MRCP	• At 6–12 months from diagnosis • Yearly × 2 years • Every 2 years (if no change)
		No high-risk stigmata or worrisome features Cyst size 20–30 mm	MRI/MRCP EUS	• EUS in 3–6 months • Yearly follow-up alternating EUS and MRI
		No high-risk stigmata Presence of worrisome features including cyst size <30 mm	MRI/MRCP EUS	• Every 3–6 months alternating EUS and MRI
		Lifetime surveillance – consider surveillance discontinuation only in patients who become unfit for surgery
European7	2018	No absolute or relative indications for surgery	MRI/MRCP or EUS Serum CA 19.9	• Every 6 months for the first year • Yearly thereafter
		No absolute indications for surgery One relative indication in patients with significant comorbidities	MRI/MRCP or EUS Serum CA 19.9	• Every 6 months
		Lifetime surveillance – consider surveillance discontinuation only in patients who become unfit for surgery

BD: branch duct; CT: computed tomography; EUS: endoscopic ultrasound; FNA: fine needle aspiration; HGD: high-grade dysplasia; IAP: International Association of Pancreatology; IPMN: intraductal papillary mucinous neoplasm; MPD: main pancreatic duct; MRCP: magnetic resonance with cholangiopancreatography; MRI: magnetic resonance imaging.

^aThe interval of follow-up can be lengthened after two years of no change.

^bA second revision of the International guidelines was made in 2012; since the guidelines did not change significantly – particularly when considering indications for surgery/surveillance – the last and updated version of the International guidelines has been included in this review.