Evaluation of transabdominal ultrasound after oral administration of an echoic cellulose-based gastric ultrasound contrast agent for gastric cancer.

ABSTRACT

BACKGROUND: With the remarkable improvements in ultrasound equipment, transabdominal ultrasound after oral administration of an echoic cellulose-based gastric ultrasound contrast agent (TUS-OCCA) has recently been suggested to be effective in initial screening of gastric cancer. The aim of this study was to evaluate the diagnostic value of TUS-OCCA for gastric cancer. METHODS: Consecutive patients with gastric cancers who underwent resection in our hospital were enrolled. Before the lesion was resected, TUS-OCCA examination was performed by a skilled examiner who was blinded to the site, size, and endoscopy diagnosis of the lesion. TUS-OCCA findings were compared with those of endoscopy and pathological diagnoses as the gold standard. RESULTS: There were a total of 288 consecutive patients enrolled in the study, including 228 with advanced gastric cancers (T2-T4 stage), 50 with early gastric cancer (26 with stage T1b and 24 with stage T1a), and 10 with high-grade intraepithelial neoplasia. TUS-OCCA had a detection rate of 100% (228/228) for advanced gastric cancers, 77% (20/26) for stage T1b, 67% (16/24) for stage T1a, and 60% (6/10) for high-grade intraepithelial neoplasia. The majority of patients with undetectable neoplasms using TUS-OCCA were obese (body mass index, 28.7-31.8 kg/m(2)). The overall accuracy of TUS-OCCA in determining the T stage of gastric cancer was 77.3% (62.5% for T1a, 70% for T1b, 71.1% for T2, 85.2% for T3, and 73.3% for T4). CONCLUSIONS: These findings indicate that TUS-OCCA achieved a high detection rate for gastric cancers and was useful in assessing the degree of gastric cancer invasion.