• 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.

• Journal of Radiation Protection and Research
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• 제41권2호
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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.

• 대한방사선기술학회지:방사선기술과학
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• 제47권1호
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• pp.13-19
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• 2024

Control of scattered radiation is one of very important factors in the use of medical radiation. In general X-ray exam, the causes, measurement methods, and the kind of detectors of scattered rays within the radiation area are diverse. In this study, the dose of scattered ray was measured by changing the thickness of the polycarbonate phantom and the tube voltage. As a result of measurement of scattered radiation, the results show that the scattered dose significantly(p<.05) increased with growing of thickness of phantom in the tube voltage 40, 50 and 60 kVp(F(p)<.05, R²>64%). As tube voltage increased at all phantom thicknesses, the scattered dose also significantly(p<.05) increased(F(p)<.05, R²>69%). In cases where a significant correlation was shown, the coefficient of determination of more than 60% was shown in regression analysis. The results of this study can be used as data on scattered radiation dose according to the tube voltage and the object thickness in general X-ray imaging exam.

• 대한방사선기술학회지:방사선기술과학
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• 제38권3호
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• pp.277-286
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• 2015

국내에 사용되고 있는 진단용 방사선발생장치는 78,000여대에 이르고 있다. 인체 대상의 진단 목적으로 사용할 때에는 의료법의 적용을 받고, 동물 대상의 진단 목적으로 사용할 때는 수의사법의 적용을 받는다. 그 이외의 목적으로 사용 시에는 원자력안전법의 적용을 받는다. 동일한 방사선발생장치라도 사용목적 및 대상에 따라 적용되는 법제가 달라지며, 다원화된 규정이 적용되는 문제점인 법제의 혼란을 방지하기 위해 법제 내용의 분석 및 비교가 필요하다. 본 연구는 질적 조사로, 원자력안전 법, 의료법, 수의사법과 그 하위 규정에 적용되는 진단용 방사선발생장치 도입에 대한 행정절차, 안전성 검사, 인력 관리, 구역 관리, 행정처분에 관한 내용이다. 원자력안전법 하위규정에서는 진단용 방사선발생장치 도입은 허가개념으로 행정절차가 복잡하고 구비요건이 많다. 사용에 따른 안전성 검사는 방사선안전관리 전 분야에 걸쳐 감사 성격의 정기검사를 받게 된다. 안전관리자 및 종사자에 대해 해마다 법정 정기 교육을 받아야 한다. 방사선관리구역을 지정하는 방사선량률 기준이 다르며 방사선량률 측정 의무가 있다. 법제 위반 시 부과되는 행정처분의 양적 차이가 최대 10배에 이르며 전 분야에 걸쳐 원자력안전법 하위규정 적용 시 방사선안전관리 부담이 가장 크다. 동일한 진단용 방사선발생장치의 사용 목적과 촬영대상에 따라 다르게 적용되고 있는 현행 법 제도 하에서는 사용주체에 따라 방사선 안전관리를 위한 법제 내용의 형평성이 결여되어 있고, 혼란의 우려가 있으므로 진단용 방사선발생장치 이용에 따른 법제의 일원화 또는 표준화 등의 대안이 필요할 것으로 예상된다.

• 한국의학물리학회지:의학물리
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• 제32권4호
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• pp.153-158
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• 2021

Purpose: This study evaluated the features of a pressure mapping system for patient motion monitoring in radiation therapy. Methods: The pressure mapping system includes an MS 9802 force sensing resistor (FSR) sensor with 2,304 force sensing nodes using 48 columns and 48 rows, controller, and control PC (personal computer). Radiation beam attenuation caused by pressure mapping sensor and signal perturbation by 6 and 10 mega voltage (MV) photon beam was evaluated. The maximum relative pressure value (mRPV), average relative pressure value (aRPV), the center of pressure (COP), and area of pressure distribution were obtained with/without radiation using the upper body of an anthropomorphic phantom for 30 minutes with 15 MV. Results: It was confirmed that the differences in attenuation induced by the FSR sensor for 6 and 10 MV photon beams were small. The differences in mRPV, aRPV, area of pressure distribution with/without radiation are about 0.6%, 1.2%, and 0.5%, respectively. The COP values with/without radiation were also similar. Conclusions: The characteristics of a pressure mapping system during radiation treatment were evaluated on the basis of attenuation and signal perturbation using radiation. The pressure distribution measured using the FSR sensor with little attenuation and signal perturbation by the MV photon beam would be helpful for patient motion monitoring.

• Radiation Oncology Journal
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• 제35권4호
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• pp.380-384
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• 2017

Massive chylous leakage is a rare postoperative complication that can prolong hospital stay and cause secondary morbidities. Conservative management strategies are the treatment of choice; however, radiation therapy (RT) can be used as an alternative for cases that are refractory to conservative treatment. Herein, we report a 69-year-old female patient who suffered from massive chylous leakage after subtotal gastrectomy. Due to persistent massive chylous leakage, she was scheduled to undergo low-dose RT. Radiation was delivered with a daily dose of 1 Gy, using an anterior-posterior and posterior-anterior beam arrangement. The clinical target volume encompassed the entire lymph node area of the D2 dissection. RT was completed at the total dose of 8 Gy because the amount of chylous leakage declined rapidly. Percutaneous drainage tube was removed after 3 days of RT. The patient did not complain of any symptoms related to massive chylous leakage 2 years after the completion of RT.

• 한국콘텐츠학회논문지
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• 제11권3호
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• pp.302-308
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• 2011

혈관 조영 검사 및 중재적 방사선 시술을 통한 환자에게 주어지는 피폭선량에 대해 대뇌를 중심으로 환자 체형을 표준화하여 검사 및 시술 차이에 따른 투시시간, 면적 선량률(kerma area product rate)을 관측하고 참고 기준치를 비교하고자 하였다. 그 결과 질병 분류에 따른 면적 선량률은 지주막하출혈(subarachnoid hemorrhage)이 가장 높았고, 뇌동맥류가 가장 낮았다. 또한 검사 및 시술에 따른 면적 선량률은 양쪽 내경동맥, 양쪽 총경동맥 및 추골동맥으로 하는 방법이 가장 높았으며, guglielmi detachable coil(GDC)이 가장 낮게 나타났다. 따라서 이를 혈관 조영 검사 및 중재적 방사선 시술시 환자 피폭 선량에 대한 참고 기준치로 이용할 수 있을 것이며 향후 환자 피폭 선량 교육과 관리에 유용할 것이라 사료된다.

• Journal of Radiation Protection and Research
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• 제46권4호
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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.

• 대한디지털의료영상학회논문지
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• 제15권1호
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• pp.47-54
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• 2013

This study evaluated the apron quality management and shield efficiency in the education laboratory for radiology students. For making a proposal of effective control of lead apron, Eighteen aprons, used in 4 university laboratories of dae-gu, Kyungpook area, were analyzed regarding their uniformities, transmission doses, lead equivalent and shield efficiencies. In conclusion, the lead apron uniformity was generally good. Also, the shield efficiency corresponding to lead equivalent was high. However, the quality control of lead apron was not satisfactory. Since there is a potentially possible chance for students to be exposed to a radiation during practical radiation-training in the education laboratory, the quality-control maintenance of the lead apron should be unceasingly maintained for the radiation protection.

• 한국방사선학회논문지
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• 제7권2호
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• pp.151-156
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• 2013

암 환자의 지속적인 증가와 이로인한 사망률이 증가하는 추세에서 부산지역에서 발생되고 있는 방사선 치료 환자의 현황을 파악함으로써 암 환자 치료 및 암 예방, 암 환자 관리에 적극적인 도움을 주고자 한다. 대상지역 3차 의료기관에서 2011년 1월부터 2012년 12월까지 내원한 환자 중 암 환자로 진단을 받은 후 방사선 치료를 받은 4462명을 대상으로 조사, 분석하였다. 그 결과 주요 7대 암종은 유방암, 자궁경부암, 폐암, 대장 직장암, 뇌종양, 인 후두암, 간암 순으로 발생하고 있었으며, 발생 1위는 유방암이었다. 전체 발생 환자 수 중에서 38.1%를 차지하고 있어, 다른 암종에 비하여 눈에 띄게 발생하고 있는 양상을 보였다. 유방암이 지속적인 증가 추세와 두드러진 발생 환자수를 가지는 암종으로 분석되었으며, 발생감소를 위한 적절한 대책과 관리가 필요할 것이다. 그러므로 유방암에 대한 발생원인과 예방방법, 적합한 관리 프로그램이 요구된다.