Radiology: Volume 255: Number 3-June 2010
In Joon Lee, MD Jeong Min Lee, MD Seung Ho Kim, MD Cheong-ll Shin, MD Jae Young Lee, MD Se Hyung Kim, MD Joon Koo Han, MD Byung Ihn Choi, MD
Purpose: To identify the computed tomographic (CT) findings in Tla and T1b cancers and to evaluate the diagnostic performance of multidetector CT with two-dimensional multiplanar reconstruction and three-dimensional CT gastrog-raphy for evaluating the preoperative staging of gastric cancer, with special emphasis on the differentiation between T1a and T1b cancers.
Materials and Methods: The institutional review board approved this retrospective study. A total of 148 patients with gastric cancer (64 Tla, 36 T1b, and 48 T2) were included. To identify CT findings in Tla and T1b cancers, two radiologists in consensus interpreted the preoperative CT images of the 100 Tl cancers to determine the morphologic characteristics to be used as staging criteria on CT images. By using univariate and multiple logistic regression analyses, the diagnostic criteria to identify Tla and T1b cancers were developed. To evaluate the diagnostic performance of multidetector CT by using the criteria, two other blinded reviewers independently analyzed the CT images of all 148 patients to assess the T (classifying the depth of invasion as Tla, T1b, or T2) and N (classifying nodal involvement as absent or present) stage. CT staging was correlated with histopathologic results. Interobserver agreement was assessed by using weighted k statistics.
Results: The detectability of T1b cancer was significantly higher than that of Tla cancer (P = .003). T1b cancer showed well-enhancing mucosal thickening more frequently than did Tla cancer (P = .002). By using the modified CT criteria, the overall accuracy values of T staging and N staging were 64.9% (96/148) and 79.1% (117/148) for reviewer 1 and 63.5% (94/148) and 83.8% (124/148) for reviewer 2, respectively. Weighted k values of T and N staging were 0.795 and 0.641, respectively.
Conclusion: On multidetector CT images, Tla cancer shows different imaging features than does T1b cancer regarding enhancing characteristics and detectability. Multidetector CT provides relatively valuable results of T and N staging, including differentiation between Tla, T1b, and T2 gastric cancers.