胃癌の診断にX線検査は不要か―必須とする立場から：表層拡大型胃癌を中心に

The Value of Radiographic Examination for the Diagnosis of Gastric Cancer with Special Reference to the Superficial Spreading Type

要旨　胃癌の術前診断におけるX線検査の意義を明確にするため，表層拡大型胃癌45例を対象として，X線・内視鏡診断と病理診断との対比検討を行った．術前の内視鏡診断とX線診断を，切除標本の組織所見再構築図と対比して，癌の拡がり，深達度，組織型診断の一致率を比較した．拡がり診断では前壁の範囲はX線よりも内視鏡検査のほうが一致率が高かったが，C領域小彎および後壁とM領域後壁は有意にX線検査が高かった（p＜0.01）．深達度診断の一致率はX線検査が有意に内視鏡検査よりも高かった（73％対47％，p＜0.05）．症例の多くは，広いm癌の一部で浸潤病巣を形成しており，浸潤範囲と深達度の判定には，X線検査による圧迫像と空気量を変化させた二重造影像が有用であった．組織型の診断では，分化型癌と未分化型癌が混在した場合，X線のほうが内視鏡検査よりも一致率が高かった（75％対33％，p＜0.05）．胃癌の術前診断において，範囲の広い癌の場合，内視鏡検査のみでは癌の正確な質的診断を行うことは極めて困難であり，X線検査によって不足した情報を補完することが必要であると考えられた．

　In order to know the value of radiographic examination for the preoperative diagnosis of gastric cancer, 45 cases of superficial spreading type of gastric cancer were analyzed. Diagnostic accuracy of radiography for the evaluation of the extent, invasive depth, and histologic type of the gastric cancers was assessed in comparison with those of endoscopic examination. In the posterior wall of the proximal two thirds of the stomach, diagnostic accuracy rates of the extent of cancer spread by radiographic examination were significantly higher than those by endoscopic examination (p＜0.01). Diagnostic accuracy rates of the depth of cancer invasion by radiographic examination were significantly higher than those by endoscopic examination (p＜0.05). In the cases of well and poorly differentiated adenocarcinomas, the accuracy rate of diagnosis of the histologic type by radiographic examination was significantly higher than that by endoscopic examination (p＜0.05). These results suggest that endoscopic examination fails to give sufficient information for the diagnosis of superficial spreading-type gastric cancers, and that radiographic examination is therefore quite important for the preoperative diagnosis.