Background: Multidetector-row CT (MDCT) may provide accurate preoperative staging of resectable gastric cancer. However, the standard methods and criteria to diagnose the T and N stages to select the patients who are good candidates for neoadjuvant chemotherapy have not been established yet.
Methods: The aim of this prospective study was to evaluate the accuracy of MDCT to diagnose the serosal invasion and nodal metastases of gastric cancer. Patients who had gastric adenocarcinoma underwent MDCT scanning using a standardized method. The T and N stage were diagnosed by prespecified criteria. The analyses were performed in the patients who had cN0-2 and M0 tumors and underwent curative gastrectomy as a primary treatment. The accuracy was calculated by comparing the results of MDCT with the histopathological findings.
Results: A total of 315 patients were analyzed. The overall diagnostic accuracy (95 % confidence interval) of T staging was 71.4 % (225 of 315, 66.2-76.1). The accuracy, sensitivity, and specificity for serosal invasion were 85.7 % (81.4-89.1), 54.5 % (42.6-66.0), and 94.0 % (90.3-96.3), respectively. The false-positive rate for serosal invasion was 6.0 % (2.9-7.7). The overall diagnostic accuracy of N staging was 75.9 % (239 of 315, 70.9-80.3). The accuracy, sensitivity, and specificity for nodal metastases were 81.3 % (76.6-85.2), 46.4 % (36.8-56.3), and 96.8 % (93.5-98.4), respectively. The false-positive rate for nodal metastases was 3.2 % (1.6-6.5 %).
Conclusions: These results suggest that MDCT provides an accurate diagnosis with high specificity and a low false-positive rate and can be used to select the patients who are candidates for preoperative chemotherapy.