• The Journal of the Korea Contents Association
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• v.18 no.11
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• pp.508-515
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• 2018

The purpose of this study was to analyze the errors of the built - in dose area product and the calibrated moving dose area product when using automatic exposure controller of the interventional equipment. And then, the importance of the dosimeter calibration and the necessity of the calibration guideline were investigated. The experimental method was to assemble the phantom into Thin, Normal, and Heavy Adult according to the NEMA Phantom manual and to measure the dose area with the built-in dose area product and the moving dose area product. As a result, in all thicknesses, the built-in dose area product showed higher doses than the moving dose area product, and the thicker the thickness, the larger the difference. In addition, paired t-test was performed for each item and there was a significant difference in each item between p<0.05. In conclusion, considering the intervention which is highly exposed to the radiation exposure, it is that we have to know the accurate dose when using the AEC of the equipment. And there is no calibration guide for the built-in dose area meter, thus calibration guidelines should be prepared.

• Journal of Radiation Industry
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• v.9 no.4
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• pp.209-216
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• 2015

It has been about 5 years since the Fukushima nuclear power plant accident, which contaminated large area with radioactive materials. It is necessary to assess radiation dose to establish evacuation areas and to set decontamination goal for the large contaminated area. In this study, we assessed temporal trend of radiation dose to the public living in the large area contaminated with radioactive materials after the Fukushima nuclear power plant accident. The dose assessment was performed based on Chernobyl model and RESRAD model for two evacuation lift areas, Kawauchi and Naraha. It was reported that deposition densities in the areas were $4.3{\sim}96kBq\;m^{-2}$ for $^{134}Cs$, $1.4{\sim}300kBq\;m^{-2}$ for $^{137}Cs$, respectively. Radiation dose to the residents depended on radioactive cesium concentrations in the soil, ranging $0.11{\sim}2.4mSv\;y^{-1}$ at Kawauchi area and $0.69{\sim}1.1mSv\;y^{-1}$ at Naraha area in July 2014. The difference was less than 5% in radiation doses estimated by two different models. Radiation dose decreased with calendar time and the decreasing slope varied depending on dose assessment models. Based on the Chernobyl dosimetry model, radiation doses decreased with calendar time to about 65% level of the radiation dose in 2014 after 1 year, 11% level after 10 years, and 5.6% level after 30 years. RESRAD dosimetry model more slowly decreased radiation dose with time to about 85% level after 1 year, 40% level after 10 years, and 15% level after 30 years. The decrease of radiation dose can be mainly attributed into radioactive decays and environmental transport of the radioactive cesium. Only environmental transports of radioactive cesium without consideration of radioactive decays decreased radiation dose additionally 43% after 1 year, 72% after 3 years, 80% after 10 years, and 83% after 30 years. Radiation doses estimated with cesium concentration in the soil based on Chernobyl dosimetry model were compared with directly measured radiation doses. The estimated doses well agreed with the measurement data. This study results can be applied to radiation dose assessments at the contaminated area for radiation safety assurance or emergency preparedness.

• The Journal of Korean Medicine
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• v.31 no.3
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• pp.1-7
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• 2010

Objectives: To introduce to TKM scientific dose conversion methods of human to animal or animal to human for new drug investigations. Methods: We searched guidelines of the FDA and KFDA, and compared them with references for drug-dose conversion from various databases such as PubMed and Google. Then, we analyzed the potential issues and problems related to dose conversion in safety documentation of new herbal drugs based on our experiences during Investigational New Drug (IND) applications of TKM. Results: Dose conversion from human to animal or animal to human must be appropriately translated during new drug development. From time to time, investigators have some difficulty in determining the appropriate dose, because of misunderstandings of dose conversion, especially when they estimate starting dose in clinical or animal studies to investigate efficacy, toxicology and mechanisms. Therefore, education of appropriate dose calculation is crucial for investigators. The animal dose should not be extrapolated to humans by a simple conversion method based only on body weight, because many studies suggest the normalization method is based mainly on body surface area (BSA). In general, the body surface area seems to have good correlation among species with several parameters including oxygen utilization, caloric expenditure, basal metabolism, blood volume and circulating plasma protein. Likewise, a safety factor should be taken into consideration when deciding high dose in animal toxicology study. Conclusion: Herein, we explain the significance of dose conversion based on body surface area and starting dose estimation for clinical trials with safety factor.

• Journal of radiological science and technology
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• v.45 no.5
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• pp.407-412
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• 2022

Cerebral aneurysm coil embolization has the advantages of accurate, low patient burden, and fast recovery time, but efforts are needed to reduce dose due to the burden of exposure radiation dose during interventional procedures. In this study, the area dose product(DAP/Gy·cm²) and fluoro time(min) according to the size of the aneurysm and the location of aneurysm were investigated according to insurance recognition regulations aneurysm classification cerebral aneurysm coil embolization. According to the research method, classification according to the size and location of the aneurysm is first, the size of the aneurysm is divided into less than 4mm, more than 4mm to less than 8mm, and more than 8mm, and second, the dose to the area based on the location site (DAP/Gy·cm²) and fluoro time(min) based on the location site were observed. As a result, the location of the cerebral aneurysm procedure was found to be the Paraclinoid site. During cerebral aneurysm coil embolization, the area dose was 107 Gy·cm² and fluoro time was 47.41 minutes, showing lower results than domestic studies, and when comparing the area dose product with foreign studies, the area dose product results were similar to that of Turkey and Saudi Arabia. It is expected that it can be used as an objective analysis indicator to establish diagnostic reference levels (DRLs) and patient radiation defense guidelines according to the size of cerebral aneurysm and location of cerebral aneurysm procedures during interventional procedures.

• Korean Journal of Digital Imaging in Medicine
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• v.14 no.2
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• pp.47-56
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• 2012

Amount of radiation exposure by seeing through fluoroscopy examination while is many patient exposure administration and unprepared misgovernment be. In this study, abdominal fluoroscopy during the scan, the dose and image quality change according to the use of grid and added filter optimized by measuring the test condition is proposed. Uses seeing through fluoroscopy examination equipment of Image Intensifier of Easy Diagnost Eleva (Philips), under tube type and uses Human phantom and measures average area dose according to grid insertion existence and nonexistence and added filter kind change. Measure sum of 29 organ dose and effective dose through PCXMC imagination simulation program and image J program through noise, SNR, image distortion was measured. Resolution, sharpness, and analyzed using the MTF curves. Fluorography the grid to insert the filter thickness and thickening and increased the average area dose and organ doses and effective dose. In the case of spot examination, when inserted grid, average area dose and organ dose and effective dose increased. Filter thickens the average area dose decreased, but the organ doses and effective dose were increased when use 0.2mmCu+1mmAl filter, decreased slightly. Noise and SNR measurements without inserting the gird, if you do not use the added filter was the lowest and when measure the distortion, 0.1mmCu+1mmAl filter was no difference of image quality in case insert grid was judged that when did not use occasion added filter that do not use grid, difference of image quality does not exist. Did not show a big difference, according to the grid and uses of the added filter sharpness, and resolution. Patient dose increases with factors that reduce the quality of the image so reckless grid and the use of the added filter when abdominal fluoroscopy examination should be cautious in using.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.657-665
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• 2017

The aim of this study was to develop and distribute a dedicated program that can easily calculate the effective dose of a patient undergoing nuclear medicine examinations, and assist in the study of dose of nuclear medicine examinations and information disclosure. The program produced a database of the effective dose per unit activity administered (mSv/MBq) of the radiopharmaceuticals listed in ICRP 80, 106 Report and the fourth addendum, was designed through Microsoft Visual Basic (In Excel) to take the effect of 5 different (Area, Clark, Solomon(=Fried), Webster, Young) of pediatric dose calculation methods and 7 different body surface area calculation methods. The program calculates the effective dose (mSv) when the age, radionuclide, substance, and amount injected in the human body is inputted. In pediatric cases, when the age is entered, the pediatric method is activated and the pediatric method to be applied can be selected. When the BSA (Body Surface Area) formula is selected in the pediatric calculation method, a selection window for selecting the body surface area calculation method is activated. When the adult dose is input, the infant dose and the effective dose (mSv) are calculated automatically. The patient effective dose calculation program of the nuclear medicine examinations produced in this study is meaningful as a tool for calculating the internal exposure dose of the human body that is most likely to be obtained in nuclear medicine examinations, even though it is not the actual measurement dose. In the future, to increase the utilization of the program, it will be produced as an application that can be used in mobile devices, so that the public can access it easily.

• Journal of radiological science and technology
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• v.44 no.1
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• pp.53-58
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• 2021

Kerma Area Product (KAP) is best indicator of radiation monitoring on radiographic examinations. KAP can be measured differently depending on the X-ray irradiation area, air kerma, souce-skin distance, type of equipment, etc. The major factors are exposure area and the air krema. The KAP currently used only considers the exposure area with X-rays and has a problem that KAP is always excessively overestimated from the dose received by an actual subject. Therefore, in this study, in order to measure the accurate KAP, a new area dose calculation that can be calculated by dividing the area where the actual X-ray is irradiated is presented, and the KAP is the real area. We compared and analyzed how much it was overestimated compared to the dose. The Skull AP projection and seven other projection were compared and analyzed, and the KAP was overestimated in each test by 52% to 60%. In this way, the effective KAP (EKAP) calculation developed through this study should be utilized to prevent extra calculation of the existing KAP, and only the accurate patient subject area should be calculated to derive the accurate area dose value. EKAP is helpful for control the patient's exposure dose more finely, and it is useful for the quality control of medical radiation exposure.

• Journal of Radiation Protection and Research
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• v.26 no.3
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• pp.291-298
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• 2001

The designed release rate of liquid effluents from radwaste treatment system should be calculated and evaluated during normal operation, including anticipated operational occurrence and be assured that the release concentration and off-site dose at unrestricted area do not exceed the limits of regulation. The expected annual release rate and off-site dose for the currently operating nuclear power plants in Korea had been calculated and evaluated using PWR-GALE and LADTAP-II which was based on USNRC Regulatory Guide 1.109. Recently, the MOST Notice 2001-2 related to release concentration and off-site dose at unrestricted area was revised to reflect the concept of ICRP-60. It is necessary for KORI 3&4 to re-calculate the release concentration and off-site dose and to compare these results with the limits of regulation. As the results of assessment, we confirmed that the release concentrations were less than its limits of MOST Notice 2001-2 and the off-site dose at unrestricted area using K-DOSE60 was 3.61E-03 mSv/yr to the age of five for the effective dose, and 4.10E-2 mSv/yr to thyroid of the age of five for the organ equivalent dose. We also confirmed the off-site dose was within the limits of MOST Notice 2001-2. Therefore, the release concentration and off-site dose re-evaluated at unrestricted area in KORI 3&4 were well below the regulation limits of MOST Notice 2001-2.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.2
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• pp.785-789
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• 2016

A key drug for treatment of EGFR mutation-positive non-small cell lung cancer is epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI). While the dosage of many general anti-tumor drugs is adjusted according to the patient body surface area, one uniform dose of most TKIs is recommended regardless of body size. In many cases, dose reduction or drug cessation is necessary due to adverse effects. Disease control, however, is frequently still effective, even after dose reduction. In this study, we retrospectively reviewed the characteristics of 26 patients at Fukuoka University Hospital between January 2004 and January 2015 in whom the EGFR-TKI dose was reduced with respect to progression free survival and overall survival. There were 10 and 16 patients in the gefitinib group and the erlotinib group, respectively. The median progression-free survival in the gefitinib group and the erlotinib group was 22.4 months and 14.1 months, respectively, and the median overall survival was 30.5 months and 32.4 months, respectively. After stratification of patients by body surface area, the overall median progression-free survival was significantly more prolonged in the low body surface area (<1.45 m2) group (25.6 months) compared to the high body surface area (>1.45 m2) group (9.7 months) (p=0.0131). These results indicate that low-dose EGFR-TKI may sufficiently control disease without side effects in lung cancer patients with a small body size.

• Journal of radiological science and technology
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• v.41 no.2
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• pp.115-122
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• 2018

We aims to perform comparative analysis on the dose area and image qualities varying on the slice thickness when using Automatic Exposure Controller (AEC) and manual exposure; thus, it wants to suggest a measure to reduce exposure dose by setting the optimal examination condition for each slice thickness. The method was to set the thickness as Thin, Normal, and Heavy adult and evaluate the dose area, spatial resolution, low contrast resolution, Signal to Noise Ratio (SNR) and Contrast to Noise Ratio (CNR) according to each slice thickness by using the AEC and the manual exposure controller. The dose area according to each slice thickness all increased both when using the AEC and the manual exposure. However, the manual exposure showed lower dose area product than the AEC. Spatial resolutions and low contrast resolutions were all observed to be higher than the evaluation standard. Also, the SNR and CNR of each thickness all increased when using the AEC. When using the manual exposure, SNR and CNR increased in all cases other than the Heavy Adult. Consequently, the Thin and Normal Adult showed dose reduction about 2 times when using the manual exposure controller, while ensuring the image quality. Heavy adult was able to maintain good image quality by using AEC.