Decreased CT-number in the pancreatic parenchyma is a reliable imaging biomarker of the presence of malignancies in patients with high-risk intraductal papillary mucinous neoplasm.

ABSTRACT

BACKGROUND: Intraductal papillary mucinous neoplasm (IPMN) is a premalignant cystic neoplasm of the pancreas and is frequently detected in imaging investigations. A proportion of the patients with IPMN develop malignancies including high-grade dysplasia and invasive carcinoma. To predict the presence of malignancies in IPMN, constant imaging follow-up is usually required. Pancreatic steatosis (PS) has been recently identified as a facilitating factor for pancreatic cancer, and can be predicted through computed tomography (CT). We hypothesized that the CT-number of the pancreatic parenchyma could be a new reliable imaging biomarker for IPMN patients. METHODS: Eighty-six patients undergoing pancreatectomy for IPMN were investigated. Using preoperative CT, the pancreatic index (PI) was calculated by dividing the CT-number of the pancreas by that of the spleen. RESULTS: Malignancies were pathologically detected in 63 cases (73.3%). Patients were divided into two cohorts according to the presence of malignancies and were compared for various factors including the PI scores. The comparison of the two cohorts detected significant differences in two parameters (CA19-9 and PI score), and the PI score was the most sensitive biomarker to predict the presence of malignancies in patients showing high-risk stigmata of IPMN. CONCLUSIONS: Pancreatic CT-number is an additional reliable imaging biomarker in distinguishing patients with IPMN having malignancies when investigating the patients showing high-risk stigmata.