Pancreatic cyst characterization: maximum axial diameter does not measure up

Area of Science:

• Gastroenterology
• Radiology
• Oncology

Background:

• Pancreatic cysts (PCs) are often risk-stratified using unidimensional size measurements.
• Maximum axial diameter (MAD) is a common but inconsistently performing metric for PC risk stratification.

Purpose of the Study:

• To evaluate if unidimensional size (MAD) accurately reflects pancreatic cyst volume and surface area.
• To assess the correlation between MAD and actual cyst measurements.

Main Methods:

• Quantitative imaging software was used to measure cyst maximum axial diameter (MAD), volume, and surface area.
• 195 non-pseudocystic PCs >1 cm were analyzed for MAD correlation with volume and surface area.
• Volumetric growth rates were assessed in cysts imaged over a year apart.

Main Results:

• A strong overall correlation was found between MAD and cyst volume (r=0.83) and surface area (r=0.93).
• However, correlations were weaker for smaller cysts (1-2 cm and 2-3 cm).
• Significant overlap in volume and surface area existed across different unidimensional size groups, and volume change predictions were often inaccurate.

Conclusions:

• Unidimensional size (MAD) is an unreliable surrogate for pancreatic cyst volume and surface area.
• Volume and surface area measurements may offer improved risk stratification and surveillance for pancreatic cysts.
• Further research is recommended to explore the utility of volumetric and surface area measurements.