ĐÁNH GIÁ GIÁ TRỊ CỦA CHỤP CẮT LỚP VI TÍNH HAI MỨC NĂNG LƯỢNG TRONG CHẨN ĐOÁN GIAI ĐOẠN UNG THƯ DẠ DÀY TRƯỚC PHẪU THUẬT

Abstract

Purpose: This study aims to evaluate the clinical utility of dual-energy computed-tomography (DECT) technique in staging and characterizing gastric cancers. Material and Methods: The prospective study was conducted on 33 patients who were confirmed gastric cancer by endoscopic biopsy at the National Cancer Hospital from August 2021 to August 2022. These patients underwent dual-phasic scans (arterial phase (AP) and portal venous phase (PP)) with DECT mode. The preoperative T and N staging results were compared between groups with pathological results as the gold standard. The iodine concentrations of the gastric lesions and LNs were measured on the iodine-based material decomposition images. All iodine concentration values were normalized against those in the abdominal aorta and defined as normalized iodine concentration (nIC) values. The short axis length of LNs and nIC values were statistically analyzed. Results were correlated with pathological findings. Results: The overall accuracies for T staging were 75.76% and 57.58% determined with the monochromatic images and the conventional images, respectively. No statistically significant difference in the overall accuracies for N staging was found between groups. During the arterial phase (AP) and venous phase (VP), the areas under the curve (AUC) were 0.923 and 0.881, respectively. If the cutoff nIC values of the extraserosal adipose tissue during the AP and VP are 0.085 and 0.08, the sensitivity and specificity in differential diagnosis between T3 and T4 will be 85.7% and 91.7%, respectively. Conclusion: The monochromatic images obtained with DECT may be used to improve T-staging accuracy. T3 and T4 nIC values of the extraserosal adipose tissue showed statistically significant differences which is helpful in the differential diagnosis between T3 and T4.