The tumor‐to‐liver ratio of the standardized uptake value is a useful FDG‐PET/CT parameter for predicting malignant intraductal papillary mucinous neoplasm of the pancreas

BACKGROUND: The present study aimed to investigate the efficacy of positron emission tomography with 18Fluoro‐deoxyglucose (FDG‐PET/CT) for predicting malignant intraductal papillary mucinous neoplasm (IPMN). METHODS: The records of 88 patients pathologically diagnosed with IPMN after surgery at Ehime University Hospital and Ehime Prefectural Central Hospital from April 2009 to December 2020 were retrospectively reviewed. The patients’ characteristics, blood chemistry, and imaging examinations were evaluated as potential predictors of malignant IPMN. Of the PET/CT results, the maximum standardized uptake value (SUVmax) of the tumor, the tumor‐to‐blood pool ratio of the SUV (TBR), and the tumor‐to‐liver ratio of the SUV (TLR) were compared. RESULTS: On pathology, the diagnosis was adenoma (IPMA) in 40 patients, high‐grade dysplasia (HGD) in 26 patients, and carcinoma (IPMC) in 22 patients. HGD and IPMC were defined as malignant IPMN. On multivariate analyses, TLR ≥ 1.3 and high‐risk stigmata were independent predictors of malignant IPMN (P = .001 and P = .007, respectively). When both HRS and TLR ≥ 1.3 were present, the positive predictive value for malignancy was 88.2%. Furthermore, TLR was significantly higher for patients with IPMC than with HGD (P = .039). CONCLUSION: TLR can be a useful predictor for differentiating benign from malignant IPMN and may be associated with postoperative outcomes.