Comparison of hydro-US and spiral CT in the staging of gastric cancer

The purpose of this study was to compare the diagnostic accuracy of hydro-ultrasonography (US) and spiral computed tomography (CT) in the staging of gastric cancer. Forty-three patients with gastric cancers confirmed at surgery underwent hydro-US and spiral CT on the same day prospectively. Hydro-US and spiral CT were done after ingestion of water. US and CT images were independently analyzed. After surgery, pathological findings according to TNM classification were compared with US and CT findings. The detection rate for T1 tumors was 75% (12/16), and all T2–T4 tumors were detected (27/27). In the T class, good correlation with pathology occurred in 55.8% of cases for US and 58.1% for CT, and there was no difference in staging accuracy between US and CT (P=.7667). Overstaging occurred in 14% for US and CT. Understaging occurred in 30.2% for US and 27.9% for CT. In the N class, good correlation with pathology occurred in 60.5% for US and 55.8% for CT, and there was no difference in staging accuracy between US and CT (P=.0949). Overstaging occurred in 4.7% for US and 18.6% for CT, and understaging occurred in 34.9% and 25.6%, respectively. The diagnostic accuracy of hydro-US and spiral CT in the staging of gastric cancer was between 55.8% and 60.5%, and there was no significant difference in staging accuracy between hydro-US and spiral CT, except for a tendency to overstaging by CT and understaging by US in the N class (P<.05).