Magnetic resonance imaging-derived fat fraction predicts risk of malignancy in intraductal papillary mucinous neoplasm

Abstract

Purpose: Assess the relationship between MRI-derived pancreatic fat fraction and risk of malignancy in intraductal papillary mucinous neoplasm (IPMN).

Methods: MRIs of patients with IPMN who underwent pancreaticoduodenectomy were analyzed. IPMN with low-grade dysplasia (n = 29) were categorized as low-risk while IPMN at high risk of malignancy consisted of those with high-grade dysplasia/invasive carcinoma (n = 33). Pancreatic fat-fraction (FF_mean) was measured using the 2-point Dixon-method. Images were evaluated for the high-risk stigmata and worrisome features according to the revised 2017 Fukuoka consensus criteria. Data on serum CA19-9, Diabetes Mellitus (DM) status, body mass index (BMI), and histological chronic pancreatitis were obtained.

Results: A significant difference in FF_mean was found between the high-risk IPMN (11.45%) and low-risk IPMN (9.95%) groups (p = 0.027). Serum CA19-9 level (p = 0.021), presence of cyst wall enhancement (p = 0.029), and solid mass (p = 0.008) were significantly associated with high-risk IPMN. There was a significant correlation between FF_mean and mural nodule size (r = 0.36, p ˂ 0.01), type 2 DM (r = 0.34, p ˂ 0.01), age (r = 0.31, p ˂ 0.05), serum CA 19-9 (r = 0.30, p ˂ 0.05), cyst diameter (r = 0.30, p ˂ 0.05), and main pancreatic duct diameter (r = 0.26, p ˂ 0.05). Regression analysis revealed FF_mean (OR 1.103, p = 0.035) as an independent predictive variable of high-risk IPMN.

Conclusion: FF_mean is significantly associated with high-risk IPMN and an independent predictor of IPMN malignant risk. FF_mean may have clinical utility as a biomarker to complement the current IPMN treatment algorithm and improve clinical decision making regarding the need for surgical resection or surveillance.

Keywords: Intraductal papillary mucinous neoplasm; Magnetic resonance imaging; Malignancy; Pancreatic steatosis.