胃癌のEUS診断

Diagnosis of Gastric Cancer Using Endoscopic Ultrasound

要旨●胃癌のEUS診断における，機器の選択，描出方法，正常胃壁の層構造，早期胃癌および進行胃癌の深達度診断と潰瘍瘢痕（UL）の評価について解説した．また，早期胃癌のEUS診断能について検討した．当院で2006年9月〜2017年8月にESDまたは外科手術を施行した早期胃癌のうち，術前にEUSを施行し，病理組織学的に検討可能であった早期胃癌1,010病変を対象とした．EUS画像が描出不良で評価できなかった病変は11.0%であった．描出不良はL領域に多くみられ，0-I型病変でも多い傾向だった．内視鏡診断，EUS診断いずれもSM2以深の診断が不良であった．ただし，内視鏡診断の深読みをEUSで修正し，ESDで切除できた病変もあり，over surgeryを避ける目的でもEUSは有用と考えられる．

　In this study of diagnosis of gastric cancer using EUS（endoscopic ultrasound）, the following were analyzed：selection of the equipment, method of visualization, layer structure of the normal stomach wall, assessment of the depth of invasion in early and advanced gastric cancer, and evaluation of ulceration. In addition, the diagnostic ability of EUS in early gastric cancer was analyzed. The study included early gastric cancer patients who underwent ESD（endoscopic submucosal dissection）or surgery between September 2006 and August 2017 at our hospital. In total, 1,010 lesions from these patients were analyzed, wherein EUS was preoperatively performed and histological evaluation was possible. The lesions that could not be evaluated due to poor visualization of EUS images constituted 11.0%. Poor visualization was common in the L region, with 0-I type lesions also showing poor visualization. Lesions deeper than SM2 could not be accurately diagnosed by endoscopy or EUS. However, in some cases, overdiagnosis by endoscopy was corrected by EUS and the lesions were resected by ESD, indicating that EUS is also useful in the prevention of excessive surgery.