Development and Validation of a Nomogram Based on CT Imaging Features for Differentiating Pancreatic Head Cancer in Periampullary Carcinomas

Purpose To construct a predictive nomogram for differentiate pancreatic head cancer from other periampullary cancers based on CT imaging features. Methods This is a retrospective analysis, Patients diagnosed with periampullary carcinoma by pathological findings from April 2013 to April 2024 were consecutively collected. The variables evaluated included imaging characteristics (direct and indirect signs) and clinical data. Univariate and multivariate regression analyses were used to find statistically significant variables. A nomogram prediction models based on regression analysis and was internally validated. Results Multivariable analysis revealed that the distance from the end of the dilated pancreatic duct to the medial wall of the papilla (P＜0.05), the distance from the end of the dilated bile duct to the medial wall of the papilla (P＜0.01), papilla enlargement（P＜0.01）, and the presence of pancreatic and/or bile ducts between the tumor and the papilla (P＜0.05)were identified as independent risk factors for differentiating pancreatic head cancer from non-pancreatic head cancers, and were used to construct a nomogram. The nomogram demonstrated high accuracy, with an AUC of 0.826 in the development cohort and 0.801 in the validation cohort. Conclusions This study is based on CT imaging features to differentiate pancreatic head cancer from non-pancreatic head cancer in periampullary cancer. Multiple imaging signs with differential diagnostic significance were obtained, Development and validation of a nomogram that integrates these imaging features, providing a basis for treatment and comprehensive assessment in the clinic. Keywords Periampullary cancer·Pancreatic head cancer·Differential diagnosis·Computed tomography (CT)·Nomogram