拡大内視鏡が早期胃癌の診断をどう変えたか─範囲診断

Variations in the Diagnostics of Early Gastric Cancer Margins by Magnifying Endoscopy with Narrow-band Imaging（ME-NBI）

要旨●拡大内視鏡観察と通常観察（色素内視鏡を含む）による早期胃癌の範囲診断能を検討した．2014年4月〜2018年3月までESD適応と考えられ，拡大内視鏡観察にて精査を行った218病変を対象とした．全周で正診できた病変は通常観察では65.1%，NBI併用拡大内視鏡観察（ME-NBI）では98.6%であった．また通常観察では17%の病変で1/2周以上で境界が不明瞭であり，術前に生検を行い切除範囲決定する必要があると考えられた．平坦型病変で通常観察だと，10.6%と正診率が低かったが，ME-NBIだと純粋0-IIb，随伴0-IIb病変にかかわらず，97.0%であり，高い正診率であった．以上の結果から術前範囲診断にはME-NBIは必須である．

　Multiple studies have reported the usefulness of magnifying endoscopy with narrow-band imaging（ME-NBI）over conventional endoscopy for diagnosing early gastric cancer margins.

　This study aimed to compare the diagnostic accuracy of the demarcation line of early gastric cancer using ME-NBI with conventional endoscopy. We enrolled 218 consecutive patients with early gastric cancer who underwent ME-NBI to determine the margins before ESD. While 65.1% cases could be delineated by conventional endoscopy, 17.0% cases couldn't be delineated even remicircle. implying the necessity of biopsy to detect the margins of those lesions just by conventional endoscopy. Conversely, 98.6% cases could be delineated by ME-NBI. From the perspective of the macroscopic type, in elevated and depressed lesions, it was easy to detect the margins by conventional endoscopy or ME-NBI. However, in flat lesions, the rates of definitive diagnosis of the margins of lesions using conventional endoscopy were only 10.6%, whereas 97.0% lesions were detected by ME-NBI. Hence, ME-NBI is necessary for determining the margins of early gastric cancer.