Can Perfusion CT Differentiate GIST from Other Benign Subepithelial Tumors in the Stomach?

Abstract

Purpose: To evaluate the diagnostic performance of perfusion computed tomography (PCT) parameters for differentiating gastrointestinal stromal tumors (GISTs) from other benign subepithelial tumors (SETs) in the stomach.Materials and Methods: Thirty-one patients with gastric SETs subsequently confirmed via surgery underwent PCT using a multidetector computed tomography (CT) scanner at 80 kVp. Two radiologists analyzed key CT features including homogeneity and degree of enhancement. PCT parameters including blood flow, blood volume, mean transit time, and permeability surface value (PS) were independently calculated by two other radiologists. Comparative analysis of the CT features and perfusion parameters of GISTs and other benign SETs was then performed. Diagnostic performances of the perfusion parameters were also evaluated using receiver operating characteristic (ROC) analysis.Results: Twenty-four patients were proven to have GISTs via histologic examination, while the remaining non-GISTs included 3 leiomyomas, 3 schwannomas, and 1 totally necrotic nodule. Among the conventional CT features, lymphadenopathy was more frequent in non-GISTs (2/7, 28.6%) than in GISTs (0/24, 0%) (p = 0.045). Among the PCT parameters, the mean PS in the areas of strongest enhancement of GISTs (25.3 ± 23.9 mL/100 g/min) was significantly higher than that of other SETs (8.8 ± 8.8 mL/100 g/min) (p = 0.029). In ROC analysis, an area under the curve of 0.774 (p = 0.03), sensitivity of 91.7%, and specificity of 57.1% were achieved when the PS cut-off was set at 7.17 mL/100 g/min.Conclusions: Perfusion parameters were helpful for differentiating GISTs from other benign SETs, as GISTs exhibited significantly higher PS than non-GISTs.