Whole-volume histogram analysis of spectral-computed tomography iodine maps characterizes HER2 expression in gastric cancer

Figure 1 Diagram of study flow. CT: Computed tomography.

Figure 2 Receiver operating characteristic curves of the diagnostic performance of spectral computed tomography histogram parameters in the identification of HER2 status. The 99^th percentile had the best overall area under the curve among parameters (0.740), with 76.2% sensitivity, 65.0% specificity, and 67.3% accuracy. ROC: Receiver operating characteristic.

Figure 3 Images from a 43-year-old woman with poorly differentiated gastric adenocarcinoma. A: Portal venous-phase spectral computed tomography image showing clear (pink) enhancement of the lesion, located at the gastric antrum; B: Histogram of parameter distributions for the whole tumor (minimum = 14.000, maximum = 50.000, mean = 31.249, standard deviation = 5.567, skewness = 0.123, kurtosis = 0.074, 1^st-99^th percentiles = 19.000, 22.000, 24.000, 28.000, 31.000, 35.000, 38.000, 41.000, and 45.000, respectively); C and D: Microscopic pathological (HE staining, 200 ×) and immunohistochemical images, respectively, showing a poorly differentiated adenocarcinoma with a Lauren classification of diffuse type, vascular and neural invasion, and negative HER2 staining.