earticle

영어

Radiation is widely used in medicine but has both benefits and risks. Three important points must be taken into account in the medical use of radiation: justification, optimization, and dose limits. However, dose limits are not established for patients when the potential benefit is greater than the exposure risk. The International Commission on Radiological Protection (ICRP) introduced the concept of diagnostic reference levels (DRLs) to optimize the protection of patients from medical radiation exposure for diagnostic and interventional procedures. The ICRP also recommended that these levels be reviewed periodically. This paper reviews the current status of DRLs in computed tomography (CT) in Japan and provides a foundation for future revisions. A literature review of the origins of DRLs in the field of CT imaging in Japan was conducted, along with a detailed discussion of the establishment of the 2020 DRLs by a project team of which the author was a member. Japan’s first medical exposure guidelines were presented by the Japan Association of Radiological Technologists in 2000. The Japan Network for Research and Information on Medical Exposures was set up in response to the so-called ‘Lancet paper incident’ in 2004, in which it was suggested that diagnostic X-rays could increase cancer incidence, as well as ICRP Publications 103 and 105, and the 2020 DRLs were established in response to ICRP Publication 135 and corresponding revisions of laws and regulations. The DRLs for CT of the brain are higher in Japan than in Western countries but are otherwise comparable. This report summarizes the historical background of setting DRLs in Japan based on a literature review and discusses the details of the 2020 DRLs in the field of CT. DRLs must be updated periodically to keep pace with changes in social conditions and advances in medical technology and equipment.