Predictive value of enhanced computed tomography in preoperative pathological grading of pancreatic neuroendocrine neoplasm / 中华消化杂志

ABSTRACT

Objective:To investigate the value of imaging features of contrast-enhanced computed tomography (CT) of pancreatic neuroendocrine neoplasm (panNEN) in predicting preoperative pathological grade.Methods:From February 2009 to August 2020, at Zhongshan Hospital affiliated to Fudan University, the CT data of 136 patients with panNEN diagnosed by surgery and pathology were retrospectively analyzed. According to World Health Organization classification of digestive tumors (5th edition, 2019), panNEN was classified into G1, G2, G3 neuroendocrine tumor (NET) and neuroendocrine carcinoma (NEC). The differences in CT values and correlative parameters of solid part of lesions with different pathological grades were compared. The receiver operator characteristic curve was drawn and the area under the curve (AUC) was calculated to evaluate the CT value and related parameters in the differential diagnosis of panNEN of different pathological grades. The Kruskal-Wallis test and chi-square test were used for statistical analysis.Results:A total of 142 tumor lesions were detected in 136 panNEN patients, of which the numbers of G1, G2, G3 NET and NEC were 58, 73, 7 and 4, respectively. Along with the increase of pathological grade, the degree of CT enhancement in the solid part of panNEN lesions gradually decreased. The CT value, CT value difference and relative density of arterial phase and venous phase of patients with G2 NET were all lower than those of patients with G1 NET (Arterial phase 105 HU, 46 to 251 HU vs. 126 HU, 57 to 195 HU; 62 HU, 6 to 212 HU vs. 81 HU, 23 to 166 HU; 1.1, 0.4 to 2.5 vs. 1.4, 0.7 to 2.0. Venous phase 90 HU, 49 to 159 HU vs. 107 HU, 63 to 162 HU; 49 HU, 9 to 134 HU vs. 62 HU, 24 to 128 HU; 1.1, 0.5 to 2.0 vs. 1.4, 0.9 to 2.0), and the differences were statistically significant ( Harterial phase=2.880, 2.607 and 3.482, Hvenous phase=3.426, 3.323 and 3.891, all P<0.05). The CT value difference, the percentage of lesion enhancement, the index of lesion enhancement in arterial phase, and the CT value difference and the index of lesion enhancement in venous phase of patients with G3 NET were all lower than those of patients with G2 NET (31 HU, 27 to 52 HU vs. 62 HU, 6 to 212 HU; 67%, 59% to 153% vs. 151%, 15% to 705%; 0.6 HU, 0.5 to 0.9 HU vs. 1.3 HU, 0.1 to 5.8 HU; 40 HU, 36 to 52 HU vs. 49 HU, 9 to 134 HU; 0.9, 0.7 to 1.6 vs. 1.5, 0.2 to 5.4), and the differences were statistically significant ( H=2.634, 2.801, 3.267, 2.264 and 2.882, all P<0.05). The relative density index of arterial phase and venous phase to identify G1 and G2 NET received maximum AUC value of 0.679 (95% confidence interval ( CI) 0.587 to 0.771, P<0.01) and 0.701 (95% CI 0.609 to 0.793, P<0.01), respectively. The index of lesion enhancement in arterial phase and venous phase to identify G2 and G3 NET received maximum AUC value of 0.875 (95% CI 0.793 to 0.956, P=0.001) and 0.828 (95% CI 0.700 to 0.956, P=0.004), respectively. Conclusion:The enhanced CT parameters of panNEN can be used to predict the pathological grade before operation.