• Nuclear Medicine and Molecular Imaging
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• 제43권4호
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• pp.259-279
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• 2009

Radioiodine ablation therapy has been considered to be a standard treatment for patient with differentiated thyroid cancer after total thyroidectomy. Patients may need to be hospitalized to reduce radiation exposure of other people and relatives from radioactive patients receiving radioiodine therapy. Medical staffs, nursing staffs and technologists sometimes hesitate to contact patients in radioiodine therapy ward. The purpose of this paper is to introduce radiation dosimetry, estimate radiation dose from patients and emphasize the safety of radiation exposure from patients treated with high dose radioiodine in therapy ward. The major component of radiation dose from patient is external exposure. However external radiation dose from these patients treated with typical therapeutic dose of 4 to 8 GBq have a very low risk of cancer induction compared with other various risks occurring in daily life. The typical annual radiation dose without shielding received by patient is estimated to be 5 to 10 mSv, which is comparable with 100 to 200 times effective dose received by chest PA examination. Therefore, when we should keep in mind the general principle of radiation protection, the risks of radiation exposure from patients are low and the medical personnel are considered to be safe from radiation exposure.

• Nuclear Engineering and Technology
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• 제55권1호
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• pp.270-277
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• 2023

Exposure to ionizing radiation induces free radicals in human nails. These free radicals generate a radiation-induced signal (RIS) in electron paramagnetic resonance (EPR) spectroscopy. Compared with the RIS of tooth enamel samples, that in human nails is more affected by moisture and heat, but has the advantages of being sensitive to radiation and easy to collect. The fingernail as a biological sample is applicable in retrospective dosimetry in cases of localized hand exposure accidents. In this study, the dosimetric characteristics of fingernails were analyzed in fingernail clippings collected from Korean donors. The dose response, fading of radiation-induced and mechanically induced signals, treatment method for evaluation of background signal, minimum detectable dose, and minimum detectable mass were investigated to propose a fingernail-EPR dosimetry protocol. In addition, to validate the practicality of the protocol, blind and field experiments were performed in the laboratory and a non-destructive testing facility. The relative biases in the dose assessment result of the blind and field experiments were 8.43% and 21.68% on average between the reference and reconstructed doses. The results of this study suggest that fingernail-EPR dosimetry can be a useful method for the application of retrospective dosimetry in cases of radiological accidents.

• 대한방사선기술학회지:방사선기술과학
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• 제38권4호
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• pp.483-489
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• 2015

현대의 의료용 방사선 발생장치는 영상을 저장하고 전송하기 위해 의료영상 표준규격으로 Digital image communications in medicine(DICOM)을 채택하고 있다. DICOM 규격에서는 피폭선량 정보 표시를 위해 DICOM dose Structured Report(DICOM dose SR)를 표준으로 제정하여 사용하고 있다. 이와 더불어 DICOM Modality Performed Procedure Step(DIOCM MPPS) 정보와 DICOM tag 정보에서도 부분적인 피폭선량 정보를 표시하고 있다. 본 연구에서는 DICOM과 관련된 피폭선량정보 표시방법에 대해 고찰하고 의료정보 시스템간의 상호연동 테스트를 위한 Integrating the Healthcare Enterprise(IHE)의 Radiation Exposure Monitoring(REM) 프로파일에 대해 살펴보았다. 의료기관에서 의료방사선피폭선량정보에 대한 품질관리를 위해서는 DICOM 정보에서 표시되는 피폭선량 정보형식에 대한 이해가 반드시 수반되어야 하고 장비도입 단계에서 관련 규격에 대한 검토가 이루어져야 한다.

• 대한방사선기술학회지:방사선기술과학
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• 제41권3호
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• pp.255-260
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• 2018

Most patients and parents and guardians display frequent anxiety due to radiation exposure during outpatient, ward, and pediatric general radiographic examinations. This is a behavior that perceives only the harmfulness of radiation. For the recognition of medical radiation, we conduct surveys on outpatients, inpatients, and pediatric parents and guardians to identify their awareness, and then use the radiation dose promotional materials After providing accurate information on the use of radiation, the outpatient, inpatient, and pediatric parents and guardians were asked to explain the change in awareness. The questionnaire items were classified into five categories: repetitive radiation awareness for diagnosis, awareness of exposure dose, availability of exposure information, awareness of radiation risk, and awareness of health problems caused by radiation. There was a statistically significant difference in the items of recognition result of medical radiation, although there was a slight difference in the individual items in the pre and post-recognition results of providing information about the radiologists of the protector and the outpatient(p<0.05). Therefore, through the installation of these promotional materials, we will improve our awareness of medical radiation safety during general radiography surveillance in the Department of Radiology to provide better quality medical information and medical services, thereby contributing to strengthening the competitiveness of the hospital.

• Nuclear Engineering and Technology
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• 제56권1호
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• pp.335-339
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• 2024

Employees of nuclear medicine facilities performing medical procedures with the use of open radioactive sources require continuous detailed control of exposure to ionizing radiation. Thermoluminescent (TL) detectors placed in dosimeters: for the whole body, for lenses, ring and wrist dosimeters were used to assess exposure. The highest whole-body exposure of (1.70 ± 1.09) µSv/GBq was recorded in nurses administering radiopharmaceutical to patients. The highest exposure to lenses and fingers was recorded for employees of the quality control zone and it was (8.08 ± 2.84) µSv/GBq and a maximum of (1261.46 ± 338.93) µSv/GBq, respectively. Workers in the production zone received the highest doses on their hands, i.e. (175.67 ± 13.25) µSv/GBq. The measurements performed showed that the analyzed workers may be classified as exposure category A. Wrist dosimeters are not recommended for use in isotope laboratories due to underestimation of ionizing radiation doses. Appropriately selected shields, which significantly reduce the dose received by employees, must be used in isotope laboratories. Periodic measurements confirmed that the appropriate optimization of exposure reduces the radiation doses received by employees.

• 대한방사선기술학회지:방사선기술과학
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• 제47권1호
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• pp.7-12
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• 2024

Medical institutions wishing to install and operate diagnostic radiation generators must complete appointment training within one year of appointment based on the 「Medical Act」 and the 「Rules on Safety Management of Diagnostic Radiation Generator Devices」 which will come into effect on January 1, 2024. Additionally, You must receive supplementary education every three years from the date you received it. The strengthening of safety management for diagnostic radiation generators used in medical institutions means that although the radiation exposure that may occur when using diagnostic radiation generators is low, the risk of carcinogenesis may be higher than previously evaluated. In addition, safety management of diagnostic radiation generators can be said to be an essential requirement because it has been reported that the incidence of leukemia and other diseases is increasing in diagnostic radiation tests. However, the safety management training targets and programs for radiation exposure management operated by other organizations other than diagnostic radiation generators are significantly different. In addition, since the public institutions that are responsible for radiation safety management are divided, there is a risk of duplicative, excessive, and under-administrative application to medical institutions and educational institutions that install and operate diagnostic radiation generators. Therefore, we would like to determine their consistency by comparing domestic and foreign related cases and the provisions of the 「Medical Act」 and the 「Nuclear Safety Act」.

• Journal of Radiation Protection and Research
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• 제42권4호
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• pp.189-196
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• 2017

Background: The effects of radiation on tissues vary depending on the radiation type. In this study, a minipig model was used to compare the effects of ${\beta}$-rays from $^{166}Ho$ and ${\gamma}$-rays from $^{60}Co$ on the skin. Materials and Methods: In this study, the detrimental effects of ${\beta}$- and ${\gamma}$-irradiation on the skin were assessed in minipigs. The histopathological changes in the skin from 1 to 12 weeks after exposure to 50 Gy of either ${\beta}$- (using $^{166}Ho$ patches) or ${\gamma}$- (using $^{60}Co$) irradiation were assessed. Results and Discussion: The skin irradiated by ${\beta}$-rays was shown to exhibit more severe skin injury than that irradiated by ${\gamma}$-rays at 1-3 weeks post-exposure; however, while the skin lesions caused by ${\beta}$-rays recovered after 8 weeks, the ${\gamma}$-irradiated skin lesions were not repaired after this time. The observed histopathological changes corresponded with gross appearance scores. Seven days post-irradiation, apoptotic cells in the basal layer were detected more frequently in ${\beta}$-irradiated skin than in ${\gamma}$-irradiated skin. The basal cell density and skin thickness gradually decreased until 4 weeks after ${\gamma}$- and ${\beta}$- irradiation. In ${\beta}$-irradiated skin lesions, and the density and thickness increased sharply back to control levels by 6-9 weeks. However, this was not the case in ${\gamma}$-irradiated skin lesions. In ${\gamma}$-irradiated skin, cyclooxygenase-2 (COX-2) was shown to be expressed in the epidermis, endothelial cells of vessels, and fibroblasts, while ${\beta}$-irradiated lesions exhibited COX-2 expression that was mostly limited to the epidermis. Conclusion: In this study, ${\beta}$-rays were shown to induce more severe skin injury than ${\gamma}$-rays; however, the ${\beta}$-rays-induced injury was largely repaired over time, while the ${\gamma}$-rays-induced injury was not repaired and instead progressed to necrosis. These findings reveal the differential effects of ${\gamma}$- and ${\beta}$-irradiation on skin and demonstrate the use of minipigs as a beneficial experimental model for studying irradiation-induced skin damage.

• 한국의학물리학회지:의학물리
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• 제27권3호
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• pp.146-155
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• 2016

As the probability of exposure to radiation increases due to an increase in the use of radioisotopes and radiation generators, the importance of a radiation safety management field is being highlighted. We intend to help radiation workers with exposure management by identifying the degree of radiation exposure and contamination to determine an efficient method of radiation safety management. The personal exposure doses of the radiation workers at the Korea Institute of Radiological & Medical Sciences measured every quarter during a five-year period from Jan. 1, 2011 till Dec. 31, 2015 were analyzed using a TLD (thermoluminescence dosimeter). The spatial dose rates of radiation-controlled areas were measured using a portable radioscope, and the level of surface contamination was measured at weekly intervals using a piece of smear paper and a low background alpha/beta counter. Though the averages of the depth doses and the surface doses in 2012 increased from those in 2011 by about 14%, the averages were shown to have decreased every year after that. The exposure dose of 27 mSv in 2012 increased from that in 2011 in radiopharmaceutical laboratories and, in the case of the spatial dose rate, the rate of decrease in 2012 was shown to be similar to the annual trend of the whole institute. In the case of the surface contamination level, as the remaining radiation-controlled area with the exception of the I-131 treatment ward showed a low value less than $1.0kBq/m^2$, the annual trend of the I-131 treatment ward was shown to be similar to that of the entire institute. In conclusion, continuous attention should be paid to dose monitoring of the radiation-controlled areas where unsealed sources are handled and the workers therein.

• The Korean Journal of Pain
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• 제27권2호
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• pp.162-167
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• 2014

Background: Although a physician may be the nearest to the radiation source during C-arm fluoroscope-guided interventions, the radiographer is also near the fluoroscope. We prospectively investigated the radiation exposure of radiographers relative to their location. Methods: The effective dose (ED) was measured with a digital dosimeter on the radiographers' left chest and the side of the table. We observed the location of the radiographers in each procedure related to the mobile support structure of the fluoroscope (Groups A, M and P). Data about age, height, weight, sex, exposure time, radiation absorbed dose (RAD), and the ED at the radiographer's chest and the side of the table was collected. Results: There were 51 cases for Group A, 116 cases for Group M and 144 cases for Group P. No significant differences were noted in the demographic data such as age, height, weight, and male to female ratio, and exposure time, RAD and ED at the side of the table. Group P had the lowest ED ($0.5{\pm}0.8{\mu}Sv$) of all the groups (Group A, $1.6{\pm}2.3{\mu}Sv$; Group M, $1.3{\pm}1.9{\mu}Sv$; P < 0.001). The ED ratio (ED on the radiographer's chest/ED at the side of the table) of Group A was the highest, and the ED radio of Group P was the lowest of all the groups (Group A, $12.2{\pm}21.5%$; Group M, $5.7{\pm}6.5%$; Group P, $2.5{\pm}6.7%$; P < 0.001). Conclusions: Radiographers can easily reduce their radiation exposure by changing their position. Two steps behind the mobile support structure can effectively decrease the exposure of radiographers by about 80%.

• 대한방사선기술학회지:방사선기술과학
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• 제43권2호
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• pp.115-121
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• 2020

In a digital radiation system using a Flat Panel Detector, we attempted to the quality control of digital radiography system using the Exposure Index and Deviation Index. Calibration was performed with the radiation quality suggested by the International Electrotechnical Commission, and through an experiment using a phantom, appropriate inspection radiation conditions applicable to medical institutions were selected. The study was conducted using the selected radiation conditions. Through those chest posterior anterior image, information such as examination conditions and exposure index was obtained. The deviation index was derived by analyzing the exposure index based on the target exposure index calculated by the phantom study. As for the analyzed exposure index, 97.1% was distributed within the range of ± 2.0 based on the deviation index. Quality control of medical images should be performed through management of inspection conditions through exposure index and deviation index and management of medical images.