Spectral CT multi-parameter imaging in preoperatively evaluation the status of lymphovascular and perineural invasion of gastric cancer

Abstract

Objective: To explore the application value of spectral CT multi-parameter imaging in preoperative assessment the status of lymphovascular invasion (LVI) and perineural invasion (PNI) in patients with gastric cancer. Methods: A total of 62 patients who underwent energy spectral CT and with pathology confirmed gastric cancer in Lanzhou Uiversity Second Hospital from September 2020 to September 2021 were retrospectively collected, which including 46 males and 16 females, aged from 36 to 71 (57.5±9.1) years. According to the presence or absence of LVI/PNI in postoperative pathological results, they were divided into the positive group (42 cases) and the negative group (20 cases). The CT values of 40 keV and 70 keV (CT40 keV, CT70 keV), iodine concentration (IC), normalized iodine concentration (NIC) were measured in the arterial phase, the venous phase, and the delay phase, and the spectral curve slope of 40 keV to 70 keV (K(40-70)) and the combined parameters (the arterial phase: AP~all, the venous phase: VP~all, the delay phase: DP~all) were calculated. Spectral parameters between the positive and negative groups were compared, and the receiver operating characteristic curve (ROC) with the area under the curve (AUC), sensitivity, specificity, and optimal threshold were calculated for evaluating the diagnostic performance of each parameter. Results: The CT40 keV, CT70 keV, K(40-70), IC, and NIC in the arterial phase and the venous phase and the CT70 keV and NIC in the delay phase of the LVI/PNI-positive group were all higher than those of the negative group [the representative parameters: the arterial phase NIC 0.14±0.04 vs 0.12±0.04, the venous phase NIC 0.5(0.5, 0.6) vs 0.4(0.4, 0.5), the delay phase NIC 0.6±0.1 vs 0.5±0.1, all P<0.05]. ROC curve analysis showed that the diagnostic efficacy of the parameters of the venous phase is better than that of the arterial phase and the delay phase, and the diagnostic efficiency of the combined parameters is better than that of the individual parameters. The AUC value, sensitivity, and specificity of the most optimal parameter VP~all of the venous phase were 0.931(95%CI:0.872-0.990), 80.95%, and 95.00%, respectively. Conclusions: In the preoperative evaluation the status of the LVI and PNI in gastric cancer, the diagnostic efficacy in the venous phase parameters is better than that in the arterial phase and delay phase, and the diagnostic efficacy of combined parameters is better than that of individual parameters.