低線量CT肺がん検診の動向と現況における課題について

Progress in the low-dose CT lung cancer screening and problems in the present situation

本稿では冒頭に低線量CT検診における動向および進展について述べ，後段で公益社団法人日本人間ドック学会会員の立場で平成20（2008）年から平成29（2017）年にかけて3回実施して同学会学術委員会に報告した，同学会会員施設における低線量CT肺がん検診に関する実態調査の概要を述べ，同検診の現時点における課題に触れたい。上記実態調査に関する詳細は「人間ドック」に記載されている各報告書^1-3）を参照していただければ幸いである。

The present status of the low-dose CT lung cancer screening and some problems were described and discussed based on the investigations carried out for 3 times in the past 10 years to the maximally 450 member facilities of Japan Society of Ningen Dock.

The 3rd investigation revealed 325 cases with lung cancer from the 289,549 examinees consisting of 201,778 males and 87,771 females. As low as 34.8％ of the examinees were given low dose exposure at or less than 2.5 mGy CTDIvol（definition value of LDCT）, whereas 51.6％ of the facilities had replied ”yes”to the usage of iterative reconstruction.

Utilization of the iterative reconstruction method is essential in order to keep the low-dose CT screening both with high diagnostic value and radiologically low invasiveness.