[Computed tomography in the preoperative staging of gastric cancer]

In gastric cancer patients, CT can demonstrate wall lesions, tumor spread to adjacent organs and metastases. Since the disease is often diagnosed in an advanced stage, some authors used CT to stage the tumor and to avoid surgery in the patients with unresectable lesions. We compared CT staging results with surgical findings in 22 gastric cancer patients. After fluid-filling and hypotonization of the stomach, CT detected gastric wall thickening in all cases. In 4 patients neoplastic nodes < 1 cm were considered as normal on CT images, while in 2 patients some nodes > 1.5 cm which had been considered as metastatic were negative at histology. Overall CT accuracy in diagnosing nodal involvement was 73%. The lack of fat plane used as the evidence of direct invasion of adjacent organs exhibited 45% overall accuracy for hepatic involvement and 82% accuracy for pancreatic involvement. Seven cases (32%) were mis-staged by CT: 4 patients (18%) were under-staged and 3 (14%) were over-staged. Since it does not always show the real extent of the disease, in the staging of gastric cancer CT is to be considered a complementary tool to surgical staging, even though it is often necessary to choose between radical or palliation surgery.