• Progress in Medical Physics
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• v.29 no.4
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• pp.123-136
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• 2018

The complex dose distribution and dose transfer characteristics of intensity-modulated radiotherapy increase the importance of precise beam data measurement and review in the acceptance inspection and preparation stages. In this study, we propose a process map for the introduction and installation of high-precision radiotherapy devices and present items and guidelines for risk management at the acceptance test procedure (ATP) and commissioning stages. Based on the ATP of the Varian and Elekta linear accelerators, the ATP items were checked step by step and compared with the quality assurance (QA) test items of the AAPM TG-142 described for the medical accelerator QA. Based on the commissioning procedure, dose quality control protocol, and mechanical quality control protocol presented at international conferences, step-by-step check items and commissioning guidelines were derived. The risk management items at each stage were (1) 21 ionization chamber performance test items and 9 electrometer, cable, and connector inspection items related to the dosimetry system; (2) 34 mechanical and dose-checking items during ATP, 22 multileaf collimator (MLC) items, and 36 imaging system items; and (3) 28 items in the measurement preparation stage and 32 items in the measurement stage after commissioning. Because the items presented in these guidelines are limited in terms of special treatment, items and practitioners can be modified to reflect the clinical needs of the institution. During the system installation, it is recommended that at least two clinically qualified medical physicists (CQMP) perform a double check in compliance with the two-person rule. We expect that this result will be useful as a radiation safety management tool that can prevent radiation accidents at each stage during the introduction of radiotherapy and the system installation process.

• Journal of radiological science and technology
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• v.41 no.3
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• pp.215-221
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• 2018

Cone beam Computed Tomography(CBCT) is an increasing trend in clinical applications due to its ability to increase the accuracy of radiation therapy. However, this leaded to an increase in exposure dose. In this study, the simulation using Monte Carlo method is performed and the absorbed dose of CBCT is analyzed and standardized data is presented. First, after simulating the CBCT, the photon spectrum was analyzed to secure the reliability and the absorbed dose of the tissue in the human body was evaluated using the MIRD phantom. Compared with SRS-78, the photon spectrum of CBCT showed similar tendency, and the average absorbed dose of MIRD phantom was 8.12 ~ 25.88 mGy depending on the body site. This is about 1% of prescription dose, but dose management will be needed to minimize patient side effects and normal tissue damage.

• Journal of Radiation Protection and Research
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• v.41 no.2
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• pp.133-140
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• 2016

Backgrounds: The accident at Fukushima Daiichi Nuclear Power Plant (NPP), March 2011, caused serious radioactive contamination over wide area in east Japan. Therefore, it is important to know the effect of the accident and the status of NPP. Materials and Methods: This paper provides a review on the status of radiation dose and radioactive contamination caused by the accident on the basis of publicized information. Results and Discussion: Monitoring of radiation dose and exposure dose of residents has been conducted extensively by the governments and various organizations. The effective dose of general residents due to the accident proved to be less than a mSv both for external and internal dose. The equivalent committed dose of thyroid was evaluated to be a few mSv in mean value and less than 50 mSv even for children. Monitoring of radioactivity concentration has been carried out on food ingredients, milk and tap water, and actual meal. These studies indicated the percentage of foods above the regulation standard was over 10% in 2011 but decreasing steadily with time. The internal dose due to foods proved to be tens of ${\mu}Sv$ and much less than that due to natural $^{40}K$ even in the Fukushima area and decreasing steadily, although high level concentration is still observed in wild plants, wild mushrooms, animals and some kind of fishes. Conclusion: According to extensive studies, not only the effect of the accident but also the pathway and countermeasures against radioactive contamination have been revealed, and they are applied very effectively for restoration of environment and reconstruction of the area.

• Journal of Radiation Protection and Research
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• v.46 no.4
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• pp.213-217
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• 2021

Background: Radiation exposure can occur as a result of occupational activities utilizing sources of radiation. The average level of occupational exposure is generally similar to the global average, but some workers receive more than this. In this study, the occupational exposure data for workers in Korea to check the recent trend of radiation exposure. Materials and Methods: The data collection and analysis are carried out by two separate periods based on the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) survey. One is the year 2003 to 2014 for a recent survey, and the other is 2015 to 2019. All available data were collected by annual reports from radiation dose registry organizations. Results and Discussion: The annual dose over the record level to the total workers did not change much compared with the total increasing number of workers in this period. The dose to the nuclear fuel cycle field has a tendency to decrease. It resulted from the efforts of radiation dose reduction with high technology introduced to this area. Also, it is important result that the radiation dose to the workers in radiography is remarkably reduced. Conclusion: The number of radiation workers and average doses were analyzed for occupational categories in Korea. It still needs cooperative efforts between the dose registry organizations for the efficient dose management of Korean radiation workers.

• Korean Journal of Digital Imaging in Medicine
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• v.14 no.1
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• pp.1-6
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• 2012

This round of tests in patients with UGI and Esophagography data collected by national and international reference levels based on the original set of guidelines and fluoroscopy, through the provision of medical radiation exposure reduction and further optimization of Defense to realize that is intended. 359 names in our hospital underwent Esophagography 302 patients who underwent UGI average fluoroscopy time and number of images to calculate the average 21 cm Acryl phantom dose for 10 seconds and 20 seconds, average area dose and the area dose of 1 spot image, 5 spot consecutive images by measuring the patient dose and third quartile of the mean area dose was set seonryangin reference dose. Esophagography average patient dose was set to 30.05 $Gy{\cdot}cm^2$, DRL was set at a 25.37 $Gy{\cdot}cm^2$. Average dose of UGI patients were selected as 45.33 $Gy{\cdot}cm^2$, DRL was set at a 34 $Gy{\cdot}cm^2$. UGI patients with established average dose recommended in the 2008 national recommendation from the UGI examination with a dose of less than 49.7 $Gy{\cdot}cm^2$ seonryangin is evaluated. This Note examines the dose of self-aware through education recognizes the importance of dose reduction and examine if their efforts and further reduce patient dose could achieve optimization of the medical exposure is considered.

• Journal of radiological science and technology
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• v.44 no.3
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• pp.195-203
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• 2021

Although intra oral dental x-ray is a lower dose than other radiological examinations, pediatric patients are known to have a higher risk of radiation damage than adults. For this reason, pediatric dental x-ray requires management of dose evaluation and imaging conditions during the examination. In this study, the dose calculation program ALARA-Dental(child/adult) was used to evaluate the organ dose and effective dose exposed to each examination site during intra oral imaging of children during dental radiographic examination, and dose analysis according to the imaging conditions was performed. As a result, the highest organ dose distribution was shown at 0.044 ~ 0.097 mGy in all are as of the mucous membrane of oral cavity except for the maxillary incisors and canines. Also, in the case of the thyroid gland, the maxillary canine and maxillary premolar examination showed 0.027 and 0.020 mGy, respectively, and the dose distribution was 15.4% to 70.0% higher than that of the mandibular examination. As for the effective dose calculated during intra oral imaging, the maxillary anterior and canine examinations showed the highest effective doses of 0.005 and 0.004 mSv, respectively, and the maxillary area examination showed a higher dose distribution on average than the mandible.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.489-492
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• 2014

This thesis provides the design of system software for the management of radiation dose that is generated using computer tomography(CT). Because radiation exposure is different depending on the difference in sensitivity to each part for each of the patient's body, if we will be able to manage an appropriate amount of radiation, it is possible to estimate the radiation exposure of the patient as a result. Recently, radiation leakage incident of Japanese nuclear power plant was in the news internationally and there is a growing interest not only a nuclear power plant, to medical radiation exposure. In spite of the fact that currently safety management of radiation is under control only the workers of the radiation involved, exposure management of patients until now have been required. Surgery and inspection using the radiation in Korea will increase, due to this medical exposure has increased, but it is a reality that medical institution don't know the level of radiation exposure applied to the patient. Therefore a system for managing the radiation exposure of the patient from the medical institution is required. This paper proposes a design of a software program to manage the radiation exposure of CT is an typical imaging tool to use the radiation in the medical institution. By check the amount of radiation dose and set the limit of dose, we would help to optimize the medical exposure of the patient.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.9-16
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• 2010

Purpose: With increasing medical use of radiation and radioactive isotopes, there is a need to better manage the risk of radiation exposure. This study aims to grasp and analyze the individual radiation exposure situations of radiation-related workers in a medical facility by specific job, in order to instill awareness of radiation danger and to assist in safety and radiation exposure management for such workers. Materials and Methods: 1 January 2007 to 31 December 2009 to work in medical institutions are classified as radiation workers Nuclear personal radiation dosimeter regularly, continuously administered survey of 40 workers in three years of occupation to target, Imaging Unit beautifully, age, dose sector, job function-related tasks to identify the average annual dose for a deep dose, respectively, were analyzed. The frequency analysis and ANOVA analysis was performed. Results: Imaging Unit beautifully three years the annual dose PET and PET/CT in the work room 11.06~12.62 mSv dose showed the highest, gamma camera injection room 11.72 mSv with a higher average annual dose of occupation by the clinical technicians 8.92 mSv the highest, radiological 7.50 mSv, a nurse 2.61 mSv, the researchers 0.69 mSv, received 0.48 mSv, 0.35 mSv doctors orderly, and detail work employed the average annual dose of the PET and PET/CT work is 12.09 mSv showed the highest radiation dose, gamma camera injection work the 11.72 mSv, gamma camera imaging work 4.92 mSv, treatment and safety management and 2.98 mSv, a nurse working 2.96 mSv, management of 1.72 mSv, work image analysis 0.92 mSv, reading task 0.54 mSv, with receiving 0.51 mSv, 0.29 mSv research work, respectively. Dose sector average annual dose of the study subjects, 15 people (37.5%) than the 1 mSv dose distribution and 5 people (12.5%) and 1.01~5.0 mSv with the dose distribution was less than, 5.01~10.0 mSv in the 14 people (35.0%), 10.01~20.0 mSv in the 6 people (15.0%) of the distribution were analyzed. The average annual dose according to age in occupations that radiological workers 25~34 years old have the highest average of 8.69 mSv dose showed the average annual dose of tenure of 5~9 years in jobs radiation workers in the 9.5 mSv The average was the highest dose. Conclusion: These results suggest that medical radiation workers working in Nuclear Medicine radiation safety management of the majority of the current were carried out in the effectiveness, depending on job characteristics has been found that many differences. However, this requires efforts to minimize radiation exposure, and systematic training for them and for reasonable radiation exposure management system is needed.

• Journal of radiological science and technology
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• v.41 no.6
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• pp.643-649
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• 2018

Recently, together with advancement of domestic aviation industry, overseas tourists using planes have been soared. This study aimed to investigate the risk of diseases for the passengers and flight attendants from the exposed cosmic radiation during the flight by domestic and international literature reviews, as follows. Airliners should develop the program to measure the actual radiation dose and prepare the portable devices for radiation measurement in flight to lower the accumulated dose of cosmic radiation by the attendants. Regulation should be prepared to check the exposed dose during the flight for the passengers by announcement of individual exposed radiation dose which has been provided only to the flight attendants. Passengers and flight attendants should recognize they are exposed to excessive cosmic radiation during the flight and civilians should be protected by the cosmic radiation when they use the flights, which should be prepared by the regulations.

• Journal of the Korea Safety Management & Science
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• v.17 no.1
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• pp.119-124
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• 2015

According as radiation therapy technique develops, standardization of radiation therapy has been complicated by the plan QA(Quality Assurance). However, plan QA tools are two type, OADT (opposite accumulation dose tool) and 3DADT (3 dimensional accumulation dose tool). OADT is not applied to evaluation of beam path. Therefore tolerance error of beam path will establish measurement value at OADT. Plan is six beam path, five irradiation field at each beam path. And beam path error is 0 degree, 0.2 degree, 0.4 degree, 0.6 degree, 0.6 degree, 0.8 degree. Plan QA accomplishes at OADT, 3DADT. The more path error increases, the more plan QA error increases. Tolerance error of OADT path is 0.357 using tolerance error of conventional plan QA. Henceforth plan QA using OADT will include beam path error. In addition, It will increase reliability through precise and various plan technique.