胃がんX線検診における撮影から読影までの精度管理

Quality Control of Radiography and Film-reading in Gastric Cancer Screening

要旨●日本消化器がん検診学会の新・胃X線撮影法と胃X線検診のための判定区分（カテゴリー分類）は，胃がんX線検診の検査精度管理に主要な役割を果たしている．前者には鉤状胃の微細な粘膜二重造影像を確実に得る方法が示されている．後者は管理区分選択の根拠を良悪性の区別や，悪性所見またはその診断の確信の度合いを6つのカテゴリー（1，2，3a，3b，4，5）選択で示すように考えられており，良性疾患の取り扱いが容易になったことと不確実所見からの拾い上げを区別したことが主な特徴である．特にカテゴリー3b比率は検査精度管理に有用である．また，認定専門放射線技師による読影補助制度は読影体制の維持に寄与することが期待される．加えて，商業ベースで導入が進んでいる遠隔読影は精度管理の実態把握と利用に関する指針作成が急務である．

　The Japanese Society for Gastrointestinal Cancer Screening suggested a new gastric radiography method and judgment classification（categorization）for gastric X-ray screening, which play vital roles in the management of quality control of radiography and film-reading for gastric cancer X-ray screening.

　The new gastric imaging technique is a dependable method for obtaining fine mucosal double contrast images of the hooked stomach. By selecting six categories（1, 2, 3a, 3b, 4, and 5）to indicate the distinction between benign and malignant and by selecting a malignant finding or a level of confidence in its diagnosis, the categorization is intended to provide the basis for selecting a management category. The primary benefits are simplified handling of benign diseases and clarification of uncertain findings. Specifically, the 3b ratio can be useful in radiography quality management. The reading assistance system provided by certified professional radiologists is expected to help maintain the reading system. In addition, there is an urgent need to understand the actual status of remote reading［0］, which is being introduced on a commercial basis, for quality control and to establish guidelines for its usage.