CLINICAL EVALUATION OF INTRALUMINALI ULTRASONOGRAPHY WITH A MICROSCANNER IN DIAGNOSING THE DEPTH GF INVASIGN GF GASTRIC CANCER

Abstract

To evaluate the ability of intraluminal ultrasonography (ILUS) with a rnicroscanner in diagnosing the depth of invasion of gastric cancer, 115 lesions of gastric cancer (early; 100, advanced; 15) were studied. The microscanner (MP-PN 20-06, Aloka Co. LTd.) applied in this study was a mechanical radial scanner with a frequency of 20/15 MHz and a diameter of six Fr. Due to its small size, the scanning of gastric lesion through the channel of a gastroscope was possible. The images obtained by the microscanner were compared with the histological findings of the resected materials in each case. In 100 lesiens of early gastric cancer, accuracy rate of the depth of invasion estimated by microscanner was 91%in m-sml cancer and 67% in sm2 cancer. We classified early gastric cancerous lesions into three groups by macroscopic findings and patterns of fibrosis. In elevated type, accuracy rate was 94% in m-sml cancer and 100% in sm2 cancer. In depressed type without fibrosis, accuracy rate was 93/ in m-sml cancer, and 83 in sm2 cancer. In depressed type with fibrosis, accuracy rate was 86% in m-sml cancerand 0% in sm2 cancer. In 15 lesions of advanced gastric cancer, the depth of invasion was diagnased accurately in 25% of mp cancer, 50% of ss cancer and 33% of se cancer. From these results we conclude that ILUS with a microscanner is excellent in evaluating minute cancerous lesions without fibroses. And PLUS is useful for the determination of indication of endoscopic mucosal resection in gastric cancer. But, this technique is unsuitable for the diagnosis of the depth of advanced gastric cancer.