Comparative analysis of computed tomography features in pancreatic neuroendocrine neoplasms with pathological Grade 1 and Grade 2        TANG Jiang-tao*, YANG Guang1, JI Meng, et al. *Department of General Surgery, Changzheng Hospital, the Second Military Medical University, Shanghai 200003, China
Corresponding author: SHAO Cheng-hao, E-mail:13801938229@163.com; SHAO Cheng-wei,E-mail:cwshao@sina.com
Abstract    Objective    To analyze the preoperative computed tomography (CT) features between G1 and G2 pancreatic neuroendocrine neoplasms (pNENs) and explore the diagnostic ability of distinguishing G1 from G2 pNENs. Methods The imaging data of 56 cases of pNENs who received preoperative enhancement CT between January 2010 and November 2015 in Changzheng Hospital and Changhai Hospital of Second Military Medical University were analyzed retrospectively. CT images of all the cases of pNENs were reviewed. Differences in clinic pathologic features and CT features between G1 and G2 pNENs were compared. ROC analysis was performed to explore the significance of relative and absolute CT value in the diagnosis of pNENs G1 and G2. Results    The tumor sizes of G2 pNENs was greater than G1 ［(4.2±3.3) cm vs. (3.0±1.4) cm，P=0.04］. G2 pNENs were more likely to be invasion growth (P＜0.01). Both absolute and relative CT value at arterial phase, portal phase and absolute CT value at delayed phase in G2 pNENs were significantly higher than those in G1 pNENs (P<0.01). Moreover, ROC analysis demonstrated that the AUC of absolute CT value at portal phase was 0.811（95%CI 0.700 to 0.922）. The specificity and sensitivity were 0.655 and 0.889, respectively. Conclusion    CT characteristics are different between G1 and G2 pNENs. Absolute and relative CT value at arterial phase, portal phase and absolute CT value at delayed phase could be used for preoperative assessment of G1 and G2 pNENs.