胃癌の診断にX線検査は不要か―必須としない立場から：拾い上げ診断

Is Radiological Examination Unessential for Diagnosing Early Gastric Cancer?: From a Negative Viewpoint

要旨　当院で初めて早期胃癌と診断された症例を対象として，その拾い上げ診断能を検討した．対象とした早期胃癌は，切除例では組織学的に発見されたもの，内視鏡的切除例では治療後1年以内に発見された新たな病変も加え補正した．X線先行例は95症例108病変で全例切除を行っていた．内視鏡先行例は209症例228病変で，そのうち60症例61病変（26.8％）は内視鏡的切除例であった．拾い上げ診断率はX線58.3％，内視鏡96.1％であったが，内視鏡的切除例には3症例3病変の早期胃癌が新たに発見された．このため，補正した診断率は94.8％であった．肉眼型，大きさ，部位，病変数などについても検討したが，内視鏡検査のほうがX線検査に比べ診断率は高かった．その要因として，内視鏡検査のほうが診断技術の習得が容易で，研修医の指導や再観察がX線検査に比べ簡便でかつ検査の場で行えるためと考えた．

　To evaluate diagnostic recognition competence of both endoscopic and radiological examination for early gastric cancer, cases which were first diagnosed as early gastric cancer in our department were reviewed. These cases included early gastric cancers, which were first found in surgical resection samples and also those which were endoscopically detected within one year after endoscopic mucosal resection therapy for an original lesion. One hundred and eight lesions in 95 cases which had been checked radiologically prior to endoscopic examination were surgically resected. Two hundred and twenty-eight lesions in 209 cases were evaluated endoscopically prior to radiological examination, and 61 lesions in 60 cases from among the total number (26.8%) were resected endoscopically. Rate of diagnostic recognition competence was 58.3% by radiological examination and 96.1% by endoscopic examination. However three lesions in three cases were detected in endoscopic resection cases after follow-up endoscopic study. Accordingly the rate of diagnostic recognition competence of endoscopic examination was revised to 94.8%. Rate of diagnostic recognition competence of endoscopic examination was higher than that of radiological examination, even when other factors such as macroscopic figure, size, location and number of lesions were taken into consideration. It seems that ease in acquiring diagnostic skill in endoscopic examination accounted for this result. Another contributing facter was that when using endoscopy it is easy to give directions to trainees and re-evaluation of lesions can be carried out on the spot.