胃癌診断におけるルーチン検査の確かさ―X線検査の立場から

Accuracy of Routine X-ray Examination for Gastric Cancer Detection

要旨　（1）prospective study：1983年1月～1984年12月に初回ルーチンX線検査を6,168例行い，うち1,006例（16.3％）に内視鏡検査を施行した結果，見逃し例も含め81例の癌を発見した（発見率1.31％)．X線診断の確かさは，癌とした73.3％，癌の疑いとした17.6％に癌を認めた．不確かさは，潰瘍とした4.3％，潰瘍瘢痕とした0.9％，良性隆起性病変とした3.3％，軽微な所見とした1.0％に癌を認めた．部位別にみた病の拾い上げと診断の確かさをみると，前壁では数は少ないが明らかな異常のみを拾い上げており，小彎や後壁では拾い上げの約80％を占めたが読み過ぎの傾向がみられた．（2）retrospective study：1980年1月～1984年12月に切除し病理検索できた早期癌70例82病変について，ルーチンX線検査の成績を検討した．大きさ別にみると，1cm未満の拾い上げは難しく，1cm以上3cm未満のものでも，隆起型の27.3％，陥凹型の32.4％を見逃していた．部位別には，前壁や大彎の拾い上げが悪かったが，多発病変や変形胃がその原因であり，後壁や小彎では，読影ミスによる見逃しが多かった．

　A routine x-ray examination of the upper gastrointestinal tract was performed in 6,168 patients who visited our department between January, 1983 and December, 1984. Out of the 6,168 patients,1,006 patients (16.3%) were referred to endoscopy and 81 patients were found to have gastric cancer (1.31%).

　In 73.3% of 60 patients who were diagnosed as having gastric cancer and in 17.6% of 68 patients whose radiologic findings were suggestive of gastric cancer, gastric cancer was discovered endoscopically. On the other hand, endoscopy with biopsy confirmed gastric cancer in 4.8% of 183 patients who were diagnosed as having benign ulcer, in 0.9% of 108 patients who were diagnosed as having ulcer scar and in 3.3% of 121 patients who were diagnosed as having benign polypoid lesion, gastric cancer was also detected endoscopically in 1.0% of 290 patients whose radiologic findings were vague mucosal abnormalities.

　Gastric cancer was detected in 9 patients who were not radiologically considered as having any abnormality in the stomach with a radiological false negative rate of 0.15%.

　Only 5.4% out of 1,604 abnormal findings which were picked up by the routine x-ray examination at the anterior wall of the stomach, but 46.5% and 31.8% out of them picked up at the lesser curvature and at the posterior wall of the stomach. Accuracy of the radiological diagnosis for the abnormalities was 70% or more at the anterior wall and lesser curvature.

　Retrospectively, routine radiological diagnosis was discussed by using 70 cases with 82 lesions of early gastric cancer operated on between January, 1980 and December, 1984. Except for five microcarcinomas, 20.7% out of 82 lesions were overlooked. Causes of errors were as follows, multiplicity (29.4%), careless reading mistake (29.4%) and deformed stomach (7.6%).