Radiological Justification for and Optimization of Nuclear Medicine Practices in Korea

Nuclear medicine is a rapidly growing discipline that employs advanced novel hybrid techniques that provide unique anatomical and functional information, as well as targets for molecular therapy. Concomitantly, there has been an increase in the attention paid to medical radiation exposure. A radiological justification for the practice of nuclear medicine has been implemented mainly through referral guidelines based on research results such as prospective randomized clinical trials. The International Commission on Radiological Protection recommends diagnostic reference levels as a practical mechanism to optimize medical radiation exposure in order to be commensurate with the medical purpose. The Korean Society of Nuclear Medicine has been implementing radiological optimization through a survey of the protocols on how each hospital determines the dose of administration of each radiopharmaceutical. In the case of nuclear medicine, radiation exposure of caregivers and comforters of patients discharged after administration of therapeutic radiopharmaceuticals can occur; therefore, optimization has been implemented through written instructions for patients, based on international recommendations. The development of patient-radiation-dose monitoring software, and a national registry and management system of patient-radiation-dose is needed to implement radiological optimization through diagnostic reference levels. This management system must work in agreement with the "Institute for Quality Management of Nuclear Medicine", and must take into account the medical reality of Korea, such as low medicine fee, in order to implement reasonable radiological justification and optimization.

The cancer risks of medical radiation exposure associated mainly with CT scans / 日本プライマリ・ケア連合学会誌

Japan has experienced serious nuclear disaster being a country hit by atomic bombs and as well as the occurrence of recent nuclear plant accidents. On the other hand, the Japanese population is exposed to higher dose of medical radiation compared to other developed countries, which is due to increasing number of diagnostic computed tomography (CT) examinations. The correlation between low-dose radiation exposure and cancer risks has been discussed nationwide since Fukushima nuclear plant accident has occurred, whereas cancer risks due to low-dose ionizing radiation from CT scans have been evident in recent large cohort studies. Though CT scan is a valuable diagnostic tool in medical practice because of its high resolution image with speed of scanning, it is crucial to evaluate whether the use of CT is appropriate weighing the benefits and possible risks. Hospitalist is required to have core competency to improve quality of medical care of the hospital and to coordinate with other departments or co-medical workers. In this regard, we discuss how hospitalist could play a role to justify the use of CT and minimize unnecessary radiological exposure, cooperating with radiologists or radiological technologists.

The health effects of low-dose radiation exposure

Low dose radiation has been defined as doses in the range under 100 mSv of low linear energy transfer (low-LET) radiation. There are two sources of ionizing radiation: natural and artificial radiation. Medical radiation exposure is the most common artificial radiation exposure. The frequency and volume of medical radiation exposure has markedly increased because of recent developments in medical technology. Radiation protection is now a concern due to the increasing use of computed tomography (CT) scans and diagnostic X-rays. This article introduced several models and hypotheses regarding the possible carcinogenic risks associated with low-LET radiation. Although opinions vary on the health effects of low level radiation exposure, current studies of medical radiation rely on exposure information collected prospectively, including cohort studies such as atomic bomb survivor studies. Although there are differences in perspective, the majority of studies have supported 'linear-no-threshold model without threshold' between low-LET radiation and the incidence of cancer risk. There is a need for further studies on medical radiation exposure including CT and positron emission tomography in order to understand the health effects of low-LET radiation, including the cancer incidence.