Although Gamma Knife irradiates much more radiation in a single session than conventional radiotherapy, there were only a few studies to measure absolute dose of a Gamma Knife. Especially, there is no report of application of International Atomic Energy Agency (IAEA) TRS-398 which requires to use a water phantom in radiation measurement to Gamma Knife. In this article, the authors reported results of the experiments to measure the absorbed dose to water of a Gamma Knife Model C using the IAEA TRS-398 protocol. The absorbed dose to water of a Gamma Knife model C was measured using a water phantom under conditions as close as possible to the IAEA TRS-398 protocol. The obtained results were compared with values measured using the plastic phantom provided by the Gamma Knife manufacturer. Two Capintec PR-05P mini-chambers and a PTW UNIDOS electrometer were used in measurements. The absorbed dose to water of a Gamma Knife model C inside the water phantom was 1.38% larger than that of the plastic phantom. The current protocol provided by the manufacturer has an intrinsic error stems from the fact that a plastic phantom is used instead of a water phantom. In conclusion, it is not possible to fully apply IAEA TRS-398 to measurement of absorbed dose of a Gamma Knife. Instead, it can be a practical choice to build a new protocol for Gamma Knife or to provide a conversion factor from a water phantom to the plastic phantom. The conversion factor can be obtained in one or two standard laboratories.
Nuclear Energy ; Plastics ; Radiotherapy ; Water

In January, 2023, the Science and Security Board of the Bulletin of the Atomic Scientists moved the hands of the Doomsday Clock forward to 90’s before midnight, reflecting the growing risk of nuclear war.1 In August, 2022, the UN Secretary-General António Guterres warned that the world is now in “a time of nuclear danger not seen since the height of the Cold War.2 The danger has been underlined by growing tensions between many nuclear armed states.1,3 As editors of health and medical journals worldwide, we call on health professionals to alert the public and our leaders to this major danger to public health and the essential life support systems of the planet—and urge action to prevent it.
Armed Conflicts ; Nuclear Energy ; Radiation

The compatibility with GammaMed-12i brachytherapy machine for an Ir-192 encapsulated source (IRRS20, KAERI, Korea) manufactured by Korea atomic energy research institute (KAERI) has been investigated. As a mechanical testing of compatibility, precise measurement of step movement with channels, measurement of curvature of radius for wire, and emergency return testing were performed. Periodic measurements of air kerma strength for 45 days were carried out to evaluate decay characteristics of Ir-192 radioisotope and comparison of dose distributions in phantom between KAERI and old sources previously used were performed by film dosimetry. KAERI source has a good compatibility with GammaMed12i machine as a result of mechanical testing. There are in good agreement with calculated values in activity characteristics and there were small differences in dose distributions around the source in comparison between KAERI and old source.
Academies and Institutes ; Brachytherapy ; Emergencies ; Film Dosimetry ; Korea ; Nuclear Energy ; Radius

The Russian military invasion of Ukraine on February 24, 2022, and Hamas’ terror attack on Israel on October 7, 2023, signaled the beginning of two of the most recent wars to make international headlines. To date, over 110 armed conflicts are taking place: over 45 in the Middle East and North Africa (Cyprus, Egypt, Iraq, Israel, Libya, Morocco, Palestine, Syria, Turkey, Yemen, Western Sahara); over 35 in Africa (Burkina Faso, Cameroon, the Central African Republic, the Democratic Republic of the Congo, Ethiopia, Mali, Mozambique, Nigeria, Senegal, Somalia, South Sudan, Sudan); 21 in Asia (Afghanistan, India, Myanmar, Pakistan, the Philippines); seven in Europe (Russia, Ukraine, Moldova, Georgia, Armenia, Azerbaijan); and six in Latin America (three each in Mexico and Colombia); with two more international armed conflicts (between India and Pakistan, and between India and China) in Asia.1 This list does not even include such problematic situations as those involving China and the South East Asia region. As though these situations of armed violence were not enough, mankind has already passed or is on the verge of passing several climate tipping points – a recent review lists nine Global core tipping elements (and their tipping points) - the Greenland Ice Sheet (collapse); West Antarctic Ice Sheet (collapse); Labrador-Irminger Seas / SPG Convection (collapse); East Antarctic Subglacial Basins (collapse); Amazon Rainforest (dieback); Boreal Permafrost (collapse); Atlantic M.O. Circulation (collapse); Arctic Winter Sea Ice (collapse); and East Antarctic Ice Sheet (collapse); and seven Regional impact tipping elements (and their tipping points) – Low-latitude Coral Reefs (die-off); Boreal Permafrost (abrupt thaw); Barents Sea Ice (abrupt loss); Mountain Glaciers (loss); Sahel and W. African Monsoon (greening); Boreal Forest (southern dieback); and Boreal Forest (northern expansion).2 Closer to home, how can we forget the disaster and devastation wrought by Super Typhoon Haiyan (Yolanda) 10 years ago to date? Whether international or non-international, armed conflicts raise the risk of nuclear war. Russia has already “rehearsed its ability to deliver a ‘massive’ nuclear strike,” conducting “practical launches of ballistic and cruise missiles,” and stationed a first batch of tactical nuclear weapons in Belarus,3 and the possibility of nuclear escalation in Ukraine cannot be overestimated.4 Meanwhile, in a rare public announcement, the U.S. Central Command revealed that an Ohio- class submarine (560 feet long, 18,750 tons submerged and carrying as many as 154 Tomahawk cruise missiles) had arrived in the Middle East on November 5, 2023.5 Indeed, “the danger is great and growing,” as “any use of nuclear weapons would be catastrophic for humanity.”
Armed Conflicts ; Nuclear Energy ; Radiation ; Climate Change ; Global Warming

Over 200 health journals call on the United Nations, political leaders, and health professionals to recognise that climate change and biodiversity loss are one indivisible crisis and must be tackled together to preserve health and avoid catastrophe. This overall environmental crisis is now so severe as to be a global health emergency.
Armed Conflicts ; Nuclear Energy ; Radiation ; Climate Change ; Global Warming

PURPOSE: Ethylenediamine-tetramethylenephosphonic acid (EDTMP) has widely used chelator for the labeling of bone seeking radiopharmaceuticals complexed with radiometals. 153Sm can be produced by the HANARO reactor at the Korea Atomic Energy Research Institute, Taejon, Korea. 153Sm has favourable radiation characteristics T1/2=46.7 h, beta max=0.81 MeV (20%), 0.71 MeV (49%), 0.64 MeV (30%) and gamma=103 keV (30%) emission which is suitable for imaging purposes during therapy. We investigated the labeling condition of 153Sm-EDTMP and imaging of 153Sm-EDTMP in normal rats. MATERIALS AND METHODS: EDTMP 20 mg was solved in 0.1 mL 2 M NaOH. 153SmCl3 was added to EDTMP solution and pH of the reaction mixtures was adjusted to 8 and 12, respectively. Radiochemical purity was determined with paper chromatography. After 30 min. reaction, reaction mixtures were neutralized to pH 7.4, and the stability was estimated upto 120 hrs. Imaging studies of each reaction were perfomed in normal rats (37 MBq/0.1 mL). RESULTS: The labeling yield of 153Sm-EDTMP was 99%. The stability of pH 8 reaction at 60, 96 and 120 hr was 99%, 95%, 89% and that of pH 12 at 36, 60, 96 and 120 hr was 99%, 95%, 88%, 66%, respectively. The 153Sm-EDTMP showed constantly higher bone uptake from 2 to 48 hr after injection. CONCLUSION: 153Sm-EDTMP, labeled at pH 8 reaction condition, has been stably maintained. Image of 153Sm-EDTMP at 2, 24, 48 hr after injection, demonstrate that 153Sm-EDTMP is a good bone seeking radiopharmaceuticals.
Academies and Institutes ; Animals* ; Chromatography, Paper ; Daejeon ; Hydrogen-Ion Concentration ; Korea ; Nuclear Energy ; Radiopharmaceuticals ; Rats

BACKGROUND: We are continually exposed to low-dose radiation (LDR) in the range 0.1 Gy from natural sources, medical devices, nuclear energy plants, and other industrial sources of ionizing radiation. There are three models for the biological mechanism of LDR: the linear no-threshold model, the hormetic model, and the threshold model. OBJECTIVE: We used keratinocytes as a model system to investigate the molecular genetic effects of LDR on epidermal cell differentiation. METHODS: To identify keratinocyte differentiation, we performed western blots using a specific antibody for involucrin, which is a precursor protein of the keratinocyte cornified envelope and a marker for keratinocyte terminal differentiation. We also performed quantitative polymerase chain reaction. We examined whether LDR induces changes in involucrin messenger RNA (mRNA) and protein levels in calcium-induced keratinocyte differentiation. RESULTS: Exposure of HaCaT cells to LDR (0.1 Gy) induced p21 expression. p21 is a key regulator that induces growth arrest and represses stemness, which accelerates keratinocyte differentiation. We correlated involucrin expression with keratinocyte differentiation, and examined the effects of LDR on involucrin levels and keratinocyte development. LDR significantly increased involucrin mRNA and protein levels during calcium-induced keratinocyte differentiation. CONCLUSION: These studies provide new evidence for the biological role of LDR, and identify the potential to utilize LDR to regulate or induce keratinocyte differentiation.
Blotting, Western ; Cell Differentiation ; Keratinocytes* ; Molecular Biology ; Nuclear Energy ; Polymerase Chain Reaction ; Radiation, Ionizing ; RNA, Messenger

Peroxisome proliferation is a cellular response to many chemical compounds affects including natural and modified fatty acids, phthalate and adipate ester plasticizers, leukotriene antagonists, acetylsalicylic acid and certain pathophysiological conditions including dramatic change of cellular morphology and enzymatic activity. Peroxisome proliferation phenomenon is seen primarily in liver and kidney. Hormones and nutritional factor can regulate peroxisome proliferation response. Sustained peroxisome proliferation can lead to hepatocarcinogenesis. The three types of peroxisome proliferator activated receptor, termed PPAR alpha, PPAR beta, and PPAR gamma, expressed in specific tissue, are consisted of a specific a nuclear receptor superfamily. After more than 10 years world wide research, the function of PPAR is clarified, as PPAR gamma, the master of thrifty genes, controls the expression of genes relative to adipogenesis, diabetes mellitus and obesity. The receptor is involved in transcriptional control of numerous cellular processes including cell cycle control, inflammation, immunoregulation and carcinogenesis.
Adipocytes ; cytology ; Animals ; Cell Differentiation ; Energy Metabolism ; genetics ; Humans ; Intracellular Signaling Peptides and Proteins ; Nuclear Receptor Coactivators ; Peroxisome Proliferators ; Receptors, Cytoplasmic and Nuclear ; genetics ; physiology ; Transcription Factors ; genetics ; physiology

Breast cancer is the most common form of cancer among korean woman. Therefore, the early detection activities of breast cancer such as breast self-examinations, clinical breast examinations, mammography are important. A yearly mammography examination has been recommended for women aged 40 and older for the early detection of breast cancer in asymptomatic periods. However, the glandular tissue of breast is the most radiation-sensitive tissue, and the determination of average glandular dose (AGD) forms an important part of the quality control of the mammographic systems. Because of the difficulty of estimating AGD directly, it is often estimated from the measurements of the incident air kerma and by applying the appropriate conversion factors. The primary objective of this study was to standardize the method of measuring AGD. The secondary objective was to evaluate the relationships between AGD per various composition and thickness of the breast using Monte Carlo simulations. As a result, we standardized the method of measuring AGD according to International Atomic Energy Agency (IAEA) guidelines (CoP: an international code of practice). Overall, AGD for mammographic practice in Korea was less than 3.0 mGy recommended by the Korea Food and Drug Adminstration (KFDA) protocol, and Korean Institute for Accreditation of Medical Image (KIAMI). The measured and simulated AGD for a given condition were calculated as 1.7 and 1.6 mGy, respectively. For the AGDs obtained, there was no significant difference between them. The simulated AGD was dependent on the fraction of glandular tissue of the breast. The AGD increases with increasing of the breast glandularity due to increasing absorption of low energy photons. The AGD also increases as a function of breast thickness. In conclusion, the results of this study could be used as a baseline to establish a reference level of radiation dose in mammography.
Absorption ; Accreditation ; Aged ; Breast ; Breast Neoplasms ; Breast Self-Examination ; Female ; Humans ; Korea ; Mammography ; Nuclear Energy ; Photons ; Quality Control

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.
Cohort Studies ; Humans ; Incidence ; Linear Energy Transfer ; Nuclear Weapons ; Positron-Emission Tomography ; Prospective Studies ; Radiation Protection ; Survivors