• 대한두경부종양학회지
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• 제20권2호
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• pp.172-176
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• 2004

Background and Objectives: Standard treatment of locally advanced laryngeal, hypopharyngeal, and some oropharyngeal cancers includes total laryngectomy. In an attempt to preserve the larynx through induction chemotherapy, we designed induction chemotherapy followed by definitive radiation in patients with potentially respectable head and neck cancer to determine whether organ preservation is feasible without apparent compromise of survival. Materials and Methods: The twenty-six patients diagnosed advanced head and neck squamous cell carcinoma, Stage III or IV (AJCC 2002) and performed organ preservation protocols in Ajou university hospital from 1994 to 2001 were included in this study. Results: Neoadjuvant chemotherapy showed an overall response rate of 84.6% and a complete remission (CR) rate was 59.1% following neoadjuvant chemotherapy and radiation. Seven of thirteen patients were able to preserve their larynges for more than two years by chemotherapy and radiation. There were no treatment related mortality after 2 cycles of induction chemotherapy. Conclusion: Although Organ preservation protocol through neoadjuvant chemotherapy and radiation need more controlled randomized study, it was considered alternative treatment modality in advanced head and neck cancer.

• Journal of Radiation Protection and Research
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• 제41권4호
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• pp.436-441
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• 2016

Background: Although nuclear disaster is considered rare, its effects are serious, and we must prepare a system to enable an effective response. Materials and Methods: Since 2010, we have been offering a two-day seminar to provide current nurses and radiological technologists with basic knowledge and train them in radiation emergency medicine (REM) techniques. This training offers lectures to deepen each specialty from the perspective of REM, as well as exercises on ways to handle irradiated and/or contaminated patients. Participants were expected to treat patients according to the concept of REM. Results and Discussion: All participants learn to assess and decontaminate contaminated wounds through drills. The questionnaire survey for participants indicated that participants were satisfied with this training and wanted to attend again. Conclusion: We believe that this training course will provide a valuable opportunity for medical professionals to gain knowledge and expertise in REM.

• Journal of Radiation Protection and Research
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• 제43권1호
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• pp.20-28
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• 2018

Background: Heat energy produced in nuclear reactors and nuclear fuel cycle facilities interactions modifies the physical properties of the shielding materials containing water content. Therefore, in the present paper, effect of the heat on shielding effectiveness of the concretes is investigated for gamma and neutron. The mass attenuation coefficients, effective atomic numbers, fast neutron removal cross-section and exposure buildup factors. Materials and Methods: The mass attenuation coefficients, effective atomic numbers, fast neutron removal cross-section and exposure buildup factors of ordinary and heavy concretes were investigated using NIST data of XCOM program and Geometric Progression method. Results and Discussion: The improvement in shielding effectiveness for photon and reduction in fast neutron for ordinary concrete was observed. The change in the neutron shielding effectiveness was insignificant. Conclusion: The present investigation on interaction of gamma and neutron radiation would be very useful for assessment of shielding efficiency of the concrete used in high temperature applications such as reactors.

• 대한방사성의약품학회지
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• 제4권2호
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• pp.95-98
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• 2018

Recently, South and North Korea summits agreed to implement the cooperation and promotion of medical healthcare at the third inter-Korean summit in Pyeongyang on September 18, 2018. Therefore, the South Korean government and its affiliated organizations have been looking for ways to establish a specific plan for support and exchanges in the field of healthcare and medical technology. In the background of the above new policy, radiation medicine technology can also contribute to the exchange in the field of healthcare and science & technology for the peaceful coexistence of one Korea. In this review, we analyzed and showed the status of healthcare and radiation medicine infrastructure in North Korea in order to further develop a plan to share the benefits of radiation medicine with North Korea in the exchange of healthcare and science & technology.

• Archives of Plastic Surgery
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• 제48권4호
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• pp.448-456
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• 2021

Background Locoregional stem cell delivery is very important for increasing the efficiency of cell therapy. Amnisite BA (Amnisite) is a freeze-dried amniotic membrane harvested from bovine placenta. The objective of this study was to investigate the retention of cells of the stromal vascular fraction (SVF) on Amnisite and to determine the effects of cell-loaded Amnisite in a porcine radiation-induced chronic wound model. Methods Initially, experiments were conducted to find the most suitable hydration and incubation conditions for the attachment of SVF cells extracted from pig fat to Amnisite. Before seeding, SVFs were labeled with PKH67. The SVF cell-loaded Amnisite (group S), Amnisite only (group A), and polyurethane foam (group C) were applied to treat radiation-induced chronic wounds in a porcine model. Biopsy was performed at 10, 14, and 21 days post-operation for histological analysis. Results Retaining the SVF on Amnisite required 30 minutes for hydration and 1 hour for incubation. A PKH67 fluorescence study showed that Amnisite successfully delivered the SVF to the wounds. In histological analysis, group S showed increased re-epithelialization and revascularization with decreased inflammation at 10 days post-operation. Conclusions SVFs had acceptable adherence on hydrated Amnisite, with successful cell delivery to a radiation-induced chronic wound model.

• Journal of Radiation Protection and Research
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• 제46권3호
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• pp.120-126
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• 2021

Background: This paper aims to evaluate the clinical utility and radiation dosimetry, for the mobile X-ray imaging of patients with known or suspected infectious diseases, through the window of an isolation room. The suitability of this technique for imaging coronavirus disease 2019 (COVID-19) patients is of particular focus here, although it is expected to have equal relevance to many infectious respiratory disease outbreaks. Materials and Methods: Two exposure levels were examined, a "typical" mobile exposure of 100 kVp/1.6 mAs and a "high" exposure of 120 kVp/5 mAs. Exposures of an anthropomorphic phantom were made, with and without a glass window present in the beam. The resultant phantom images were provided to experienced radiographers for image quality evaluation, using a Likert scale to rate the anatomical structure visibility. Results and Discussion: The incident air kerma doubled using the high exposure technique, from 29.47 µGy to 67.82 µGy and scattered radiation inside and outside the room increased. Despite an increase in beam energy, high exposure technique images received higher image quality scores than images acquired using lower exposure settings. Conclusion: Increased scattered radiation was very low and can be further mitigated by ensuring surrounding staff are appropriately distanced from both the patient and X-ray tube. Although an increase in incident air kerma was observed, practical advantages in infection control and personal protective equipment conservation were identified. Sites are encouraged to consider the use of this technique where appropriate, following the completion of standard justification practices.

• Nuclear Engineering and Technology
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• 제55권11호
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• pp.4204-4212
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• 2023

Background: Storage reservoirs of radioactive waste could be the source of atmospheric pollution due to the efflux of aqueous aerosol from their water areas. The main mechanism of formation of aqueous aerosols is the collapse of gas bubbles at the water surface. In this paper, we discuss the potential influence of biological factors on gas ebullition in the water areas of the radioactively contaminated industrial reservoirs R-9 (Lake Karachay) and R-4 (Metlinsky pond) of the Mayak PA. The emission of the released non-dissolved gases captured with gas traps in reservoir R-9 was (88-290) ml/m² per day (2015) and in reservoir R-4 (270-460) ml/m² per day (2016). The analysis of gas composition in reservoir R-4 (60% methane, 35% nitrogen, 2.4% oxygen, 1.5% carbon dioxide) confirms their biological origin. It is associated with the processes of organic matter destruction in bottom sediments. The major source of organic matter in bottom sediments is the dying phytoplankton developing in these reservoirs. Conclusion: The obtained results form the basis to set a task to quantify the relationship between the phytoplankton development, gases ebullition and radioactive atmosphere contamination.

• Journal of Radiation Protection and Research
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• 제46권1호
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• pp.14-23
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• 2021

Background: For radiological protection and control, the International Commission on Radiological Protection (ICRP) provides the nominal risk coefficients related to radiation exposure, which can be extrapolated using the excess relative risk and excess absolute risk obtained from the Life Span Study of atomic bomb survivors in Hiroshima and Nagasaki with the dose and dose-rate effectiveness factor (DDREF). Materials and Methods: Since it is impossible to directly estimate the radiation risk at doses less than approximately 100 mSv only from epidemiological knowledge and data, support from radiation biology is absolutely imperative, and thus, several national and international bodies have advocated the importance of bridging knowledge between biology and epidemiology. Because of the accident at the Tokyo Electric Power Company (TEPCO)'s Fukushima Daiichi Nuclear Power Station in 2011, the exposure of the public to radiation has become a major concern and it was considered that the estimation of radiation risk should be more realistic to cope with the prevailing radiation exposure situation. Results and Discussion: To discuss the issues from wide aspects related to radiological protection, and to realize bridging knowledge between biology and epidemiology, we have established a research group to develop low-dose and low-dose-rate radiation risk estimation methodology, with the permission of the Japan Health Physics Society. Conclusion: The aim of the research group was to clarify the current situation and issues related to the risk estimation of low-dose and low-dose-rate radiation exposure from the viewpoints of different research fields, such as epidemiology, biology, modeling, and dosimetry, to identify a future strategy and roadmap to elucidate a more realistic estimation of risk against low-dose and low-dose-rate radiation exposure.

• Asian Pacific Journal of Cancer Prevention
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• 제15권6호
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• pp.2793-2796
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• 2014

Background: Glioblastoma multiform (GBM) is a highly aggressive tumor with median survival of approximately 14 months. Management consists of maximal surgical resection followed by post-operative chemoradiation with concurrent then adjuvant temozolamide. The standard radiotherapy dose is 60Gy in 2-Gy fractions recommended by the radiation therapy oncology group (RTOG). With the vast majority of tumor recurrences occurring within the previous irradiation field and the poor outcome associated with standard therapy, regimens designed to deliver higher radiation doses to improve local control and enhance survival are needed. In this study, we report a single institutional experience in treatment of 68 consecutive patients with GBM, treated with resection, and given post-operative radiotherapy followed by concurrent and/or adjuvant chemotherapy. Results: Of the 80 patients who entered this study, 68 completed the treatment course; 45 (66.2%) males and 23 (33.8%) females with a mean age at diagnosis of $49.0{\pm}12.9$ (21-75) years. At a median follow up of 19 months, 39 (57.3%) patients had evidence of tumor progression and 36 (52.9%) had died. The median over all survival for all patients was 16 months and progression free survival for all patients was 6.02 months. All potential prognostic factors were analyzed to evaluate their effects on overall survival. Age ${\leq}50$ year, concurrent and adjuvant chemotherapy and extent of surgery had significant p values. We found lower progression rate among patients who received higher doses of radiotherapy (>60Gy). Higher radiation doses improved progression free survival (p=0.03). Despite increasing overall survival, this elevation was not significant. Conclusions: This study emphasize that higher radiation doses of (>60Gy) can improve local control and potentially survival, so we strongly advise prospective multi centric studies to evaluate the role of higher doses of radiotherapy on GBM patient outcome.

• Journal of Radiation Protection and Research
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• 제44권4호
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• pp.156-160
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• 2019

Background: To compare the dose of radiation received by the fetus in a pregnant patient irradiated for head and neck cancer using helical tomotherapy and three-dimensional conformal radiation therapy (3DCRT). Materials and Methods: The patient was modeled with a humanoid phantom to mimic a gestation of 26 weeks. Radiotherapy with a total dose of 2 Gy was delivered with both tomotherapy (2.5 and 5.0 cm jaw size) and 3DCRT. The position of the fetus was predicted to be 45 cm from the field edge at the time of treatment. The delivered dose was measured according to the distance from the field edge and the fetus. Results and Discussion: The accumulated dose to the fetus was 1.6 cGy by 3DCRT and 2 and 2.3 cGy by the 2.5 and 5 cm jaw tomotherapy plans. For tomotherapy, the fetal dose with the 2.5 cm jaw was lower than that with the 5 cm jaw, although the radiation leakage was greater for 2.5 cm jaw plan due to the 1.5 fold longer beam-on time. At the uterine fundus, tomotherapy with a 5 cm jaw delivered the highest dose of 2.4 cGy. When the fetus moves up to 35 cm at the 29th week of gestation, the resultant fetal doses for 3DCRT and tomotherapy with 2.5 and 5 cm jaws were estimated as 2.1, 2.7, and 3.9 cGy, respectively. Conclusion: For tomotherapy, scattering radiation was more important due to the high monitor unit values. Therefore, selecting a smaller jaw size for tomotherapy may reduce the fetal dose. however, evaluation of risk should be individually performed for each patient.