• The Journal of Korean Society for Radiation Therapy
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• v.34
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• pp.83-92
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• 2022

Purpose: To evaluate usefulness of Tomotherapy and Halcyon VMAT treatment in radiation therapy for bi-breast cancer Materials and Methods: For 10 patients with bi-breast cancer, volumetric modulated arc therapy(VMAT) treatment plan was established using helical Tomotherapy(Accuray. USA) with field width of 5.0-cm and pitch of 0.287, and Halcyon(Varian Medical System, Palo Alto, CA, Version 3.0 USA) of 6arc and 8arc. Prescribed dose was 42.4 Gy/16, and V _40.3Gy of Planning Target Volume(PTV) was 90%. The quality of plan was evaluated by comparing the dose to tumor and normal organs, and the efficiency was evaluated by comparing total MU and beam on time. Results: About three treatment plans(Tomotherapy, Halcyon 6Arc VMAT, Halcyon 8Arc VMAT) , the mean homogeneity index(H.I) of PTV were 1.07, 1.10, 1.11, and the mean conformity index(C.I) of PTV were 1.21, 1.16, 1.17, respectively. The average value of the dose assessment item for a normal organ is V _5Gy(%) of both lung was 36.3, 31.2, 29.7, and V _15Gy(%) were 18.6, 15.5, 14.6, respectively. The mean heart dose(Gy) were 4.17, 2.69, 2.51. Total MU were (7498.6, 2494.2, 2471.5), and beam on time(sec) were 462.5, 195.4, 198.0. Conclusion: Halcyon VMAT showed similar quality of treatment plan compared to helical Tomotherapy, while also protecting normal organs. In addition, the efficiency of radiotherapy increased due to a decrease in Beam On Time and MU.

• Radiation Oncology Journal
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• v.20 no.2
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• pp.139-146
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• 2002

Purpose : This study evaluated the treatment outcomes, patterns of failure, and treatment related complications of primary lymphoma patients who received definitive radiation therapy. Materials and Methods : A retrospective analysis was undertaken for 31 patients with primary orbital lymphoma at the Asan Medical Center between February 1991 and April 2001. There were 18 males and 13 females with ages ranging from 3 to 73 years (median, 44 years). The involved sites were 9 conjunctivae, 12 eyelids and 10 other orbits. The histological types were 28 MALT lymphomas (low-grade B-cell lymphoma of mucosa-associated lymphoid tissue type), 1 diffuse large B-cell lymphoma, 1 anaplastic large cell lymphoma and 1 lymphoblastic lymphoma. The Ann Arbor stages were all IE $(100\%)$. Ann Arbor stage III or IV patients were excluded from this study, Bilateral orbital involvement occurred in 6 cases. Radiation therapy was given with one anterior port of high energy electrons $(6\~16\;MeV)$ for the lesions located at the anterior structures like the conjunctivae or eyelids. Lesions with a posterior extension or other orbital lesions were treated with 4 or 6 MeV photons with appropriately arranged portals. In particular, lens blocks composed of lead alloy were used in conjunctival or eyelid lesions. Twelve patients received chemotherapy. The median follow-up period was 53 months. Results : The 5-year overall, cause-specific, and disease-free survival was $91\%,\;96\%,\;and\;80\%$, respectively. The complete response rate 6 months after radiation therapy was $100\%$. Local recurrences were observed in 2 patients at 16 and 18 months after completion of radiation treatment. They were salvaged with additional radiation therapy. Two patients developed distant metastases. A MALT lymphoma patient with a lung relapse was successfully salvaged with radiotherapy, but the other lymphoblastic lymphoma patient with bone marrow relapse expired. There were no severe complications but 5 patients developed radiation-induced cataracts and 2 patients developed dry eye. Conclusion : Most primary orbital lymphomas consisted of MALT lymphomas. Radiation therapy was a successful treatment modality for orbital lymphoma without any severe complications. In cases of local relapses, radiation therapy is also a very successful salvage treatment modality.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.4
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• pp.131-145
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• 2019

Korea has set up a radiation emergency planning zone based on the 「Act on Physical Protection and Radiological Emergency」 to protect residents living near nuclear power plants in the event of nuclear disasters. Little research has been conducted on the appropriateness of existing nuclear evacuation facilities because of a general lack of interest in nuclear accidents. This research addresses this gap by analyzing the location adequacy of evacuation facilities in Busan's emergency protection planning area based on vulnerable populations and accessibility analyses. The Gijang-gun which has the greatest risk, shows that only 4.05% of the total urban area was included in the evacuation service area within 5 minutes while only 36.93% of Geumjeong-gu and 37.23% of Haeundae-gu were included in the evacuation-enabled area. In addition, evaluation facilities in the elderly population hotspots were lacking, and there was a wide gap between dongs within the same Gu. Thus, additional evacuation facilities need to be designated and installed considering the spatial equity between areas and safety of both the public and vulnerable populations.

• Journal of radiological science and technology
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• v.34 no.3
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• pp.209-214
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• 2011

Goal of this study was to measure effective radiation dose of highly exposed patients who were treated by TACE, interventional radiology from June to September 2010. The effective radiation dose was approximately measured by weighted DAP (dose area product) with the ionization chamber which is inserted in angiography equiment (Philips Allura Xper FD 20). Radiation dose was measured by TLD which was attached to patients' thyroid and genital gland. The average of ED (effective dose) was 18.43${\pm}$6.63 mSv per person and the average of radiation dose of thyroid and genital gland was 0.37 mSv, 0.77 mSv, respectively. The mean radiation dose of operators who wear the protector was 0.07 mSv for thyroid, and 0.01 mSv for genital gland, respectively. All staffs involved in TACE treatment, have to keep them aware and use the appropriate protectors to reduce the radiation dose of patient.

• Progress in Medical Physics
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• v.21 no.2
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• pp.183-191
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• 2010

In this study, the patient with localized prostate cancer who had previously been treated at Ajou University Hospital was randomly selected since March, 2009. we performed IMRT and 2RA plans and the same dose objectives were used for CTVs, PTVs, rectum, bladder, and femoral head of the respective plans. Arc optimizations and dose calculations were performed using Eclipse versions 8.6. In this paper, we evaluated the performance of IMRT and RA plans to investigate the clinical effect of RA for prostate cancer case. In our comparison of treatment techniques, RA was found to be superior to IMRT being better dose conformity of target volume. As for the rectum and bladder, RA was better than IMRT at decreasing the volume irradiated. RA has the ability to avoid critical organs selectively through applied same dose constraints while maximally treating the target dose. Therefore, this result suggests that there should be less rectal toxicity with RA compared with IMRT, with no compromise in tumor margin. These findings, which show more favorable rectal, bladder, and femoral head DVHs with RA, imply that should not result in excess risk of toxicity when this technique is used. Many experiences with RA have shown not only dosimetric advantage, but also improved clinical toxicity when comparing with IMRT. The main drawbacks of RA are the more complex and time-consuming treatment planning process and the need for more exact physics quality assurance (QA).

• Progress in Medical Physics
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• v.13 no.1
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• pp.32-36
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• 2002

For Intensity Modulated Radiation Therapy(IMRT), the spatial resolution of intensity map(IM) is limited by the width of multi-leaf collimator, which would make an effect on the conformity of the target, as well as organs at risk. Several Methods are suggested to increase the spatial resolution, which can be categorized by the hardware-dependent technique and the software-based technique. However the best solution might be to make the width of MLC finer. it has several obstacles in the respects of technical difficulty and cost. This preliminary study is designed to investigate the clinical effectiveness of the virtual-micro IMRT(VMIMRT) technique, one of the software-based technique. A particular intensity map was created, which has 42$\times$54 pixel dimension ,0.5cm pixel size and 15 intensity levels. Using this intensity map, segment fields of IMRT were generated with 1$\times$lcm, 0.5$\times$1cm, 0.5$\times$0.5cm(VMIM) beamlet size, respectively As results, we found that there was no evidence of improvement for VMIMRT, compared with the 0.5$\times$lcm beamlet size which can be delivered by 1cm width MLC. The reason seems to be due to the constraint of VMIMRT. Further study is required to prove the benefit of the VIMRT in clinical case like head and neck cancer, where is expected that higher resolution than 1cm is necessary.

• Journal of Radiation Protection and Research
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• v.32 no.2
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• pp.79-88
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• 2007

When an accident occurs at nuclear power plant and radionuclide material is released to the area around the plant, public evacuation is considered as a measure to protect the safety of the residents nearby. This study draws factors required to estimate evacuation time and make estimation of the time to evacuate all residents from the EPZ of Wolsong site in consideration of traffic condition in the neighborhood and on the basis of field data around the site for each factor. The traffic capacity and the traffic volume by season were investigated for the traffic analysis and simulation within EPZ of Wolsong site. As a result, the background traffic volume by season were established. To estimate TGT(Trip Generation Time), the questionnaire surveys were carried out for resident and transient. The TSIS code was applied to traffic analysis in the events of daytime/night and normal/adverse weather under normal day/summer peak traffic condition. The results showed that the evacuation time required for total vehicles to move out from EPZ took generally from 118 to 150 minutes. The evacuation time took longer maximum 17 minutes at night than daytime during summer peak traffic.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.6
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• pp.807-813
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• 2014

The objective of the present study was to investigate the protective effects of anthocyanin-enriched extract from radiation-induced blackberry (Rubus fruticosus L.) mutant (${\gamma}$-B201) against carbon tetrachloride ($CCl_4$)-induced liver injury in Spargue-Dawley (SD) rats. The in vivo results show that ${\gamma}$-B201 attenuated the levels of serum aspartate aminotransferase, alanine aminotransferase, and liver lipid peroxidation in $CCl_4$-treated SD rats. Histopathological examination of rat livers showed that ${\gamma}$-B201 reduced the incidence of liver lesions induced by $CCl_4$. Moreover, ${\gamma}$-B201 prevented DNA damage in $CCl_4$-treated SD rats. Furthermore, administration of ${\gamma}$-B201 significantly increased the activity of antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR), in $CCl_4$-treated rat livers. In conclusion, the present study suggests that ${\gamma}$-B201 blackberry extract protects the liver from $CCl_4$-induced hepatic damage through an antioxidant mechanism. Therefore, ${\gamma}$-B201 blackberry may be functional food material for human health.

• Journal of the Korean Society of Radiology
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• v.8 no.4
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• pp.189-201
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• 2014

The purpose of this study was to survey guardian's opinion on assisting pediatric radiography and their level of awareness of radiation, improving the quality of pediatric radiography. In this study, the recognition was analyzed for 210 parents of child patients in Pusan National University Hospital from August 20 to September 15, 2013. A total of 66.2 percent of the respondents said they had participated in pediatric radiography in the past. The reason why they did is "Radiologist's request", the highest. According to the survey, 84.3 percent said they thought it is necessary to attending patient in pediatric radiography. "The stability of the child" is the reason for it. And respondents who thought there's no need to do that answered back, the reason for this is "Radiologist's work." There was a significant difference on the psychological state for the medical radiation by gender and child age. (p<0.05) In the analysis of recognition for the radiation, there was the significance by gender and education. (p<0.05) Regarding the awareness of the radiation protector, there was a statistical significance in age, gender, child age and education. (p<0.05) Considering the results, pediatric patient's guardians recognized that it is necessary to attend a child on X-ray for their child's stability and accurate exam above all. It must make guardians wear X-ray protector and radiologist should let the guardians recognize the X-ray examination method, before starting pediatric x-ray. It needs to improve the atmosphere of the examination room and to be considered to take visual and auditory approaches in comfort for reducing the children's fear and anxiety.

• Journal of the Korean Society of Radiology
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• v.12 no.7
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• pp.895-908
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• 2018

As modern science is developed and advanced, examination and number of times using radiation are increasing daily. General diagnostic X-ray generator is installed on stationary form, But X-ray generator was developed because patient who is in the intensive care unit, operation room, emergency room can not move to general x-ray room. What we examine patient by x-ray generator is certainly necessary, So patient exposure is inevitable. but reducing radiation exposure is highly important matter about radiation technology, guardian, patient in the same hospital room, nurse etc. For this reason, rule regarding safety control of diagnostic x-ray generator revised for radiation worker, patient and protector proclaim that mobile diagnostic x-ray shield must placed in case of examine different location excluding operation room, emergency room, intensive care unit. But, radiogical technologist is having a lot of difficulties to examine with mobile x-ray generator, diagnostic x-ray shield partition, image plate and lead apron. So, when we use x-ray generator, we manufacture shield tools can be attached to the mobile x-ray generator On behalf of x-ray shield partition and conduct analysis and in comparison to part of body and distribution of dose rate and find way to reduce radiation exposure through distribution of dose rate of patient within the radiogical technologist, medical team. Mobile x-ray generator aimed at SHIMADZU inc. R-20, We manufactured equipment for shielding x-ray scattered x-ray by installing shielding wall from side to side based on support beam on the mobile x-ray generator. Shielding wall when moving can be folded and designed to expand when examine. Experiment measured five times in each by an angle for dose rate of eyes, thyroid, breast, abdomen and gonad on exposure condition of upper and lower extremity, chest, abdomen which is examined many times by mobile x-ray generator. We used dosimeter RSM-100 made by IJRAD and measured a horizontal dose rate by body part. The result of an experiment, shielding decreasing rate of the front and the rear showed 77 ~ 98.7%. Therefore using self-production shielding wall reduce scattered x-ray occurrence rate and confirm can decrease exposure dose consequently. Therefore, through this study, reduction result which is used shielding wall of self-production will be a role of shielding optimization and it could be answer about reduction of medical exposure recommended by ICRP 103.