• 방사선산업학회지
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• 제12권4호
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• pp.303-310
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• 2018

Since Roentgen discovered X-rays, radiation sources have been utilized for many areas such as agriculture, industry, medicine and fundamental chemical research. As a result, human society has gained lots of benefits. However, if a radioactive material is used for the malicious purpose, it causes serious consequences to humanity and environment. Consequently, international organizations including International Atomic energy Agency (IAEA) have been emphasizing establishment and implementation of security management to prevent sabotage and illicit trafficking of radioactive materials. For this reason, the rule of technical standards of radiation safety management was revised and the public notice of security management regarding radioisotope was legislated in 2015 by Nuclear Safety and Security Commission (NSSC). Several radioactive sources which have to be regulated under the above rule and the public notice have been utilized in Advanced Radiation Technology Institute (ARTI) of Korea Atomic Energy Research Institute (KAERI). In order to control them properly, security management system such as access control and physical protection has been adapted since 2015. In this paper, we have analyzed the public notice of NSSC and its field application case. Based on the results, we are going to draw improvement on the public notice of NSSC and security system.

• 대한방사선기술학회지:방사선기술과학
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• 제45권4호
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• pp.313-320
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• 2022

Both angiography and interventional procedures accompanied by angiography provide many diagnostic and therapeutic benefits to patients and are rapidly increasing. However, unlike general radiography or computed tomography using the same X-ray, the amount of radiation is quite high, but the dose range can vary considerably for each patient and operator. The high sensitivity of the lens to radiation during cerebral angiography and neurointervention is already well known, and although there are many related studies, it is insufficient to easily reduce radiation in diagnosis and treatment. In this situation, in particular, by adding three-dimensional rotational angiography (3D-RA) to the existing two-dimensional (2D) angiography, it is now possible to make an accurate diagnosis. However, since this 3D-RA acquires images through projection of more radiation than before, the exposure dose of the lens may be higher. Therefore, we tried to analyze whether the radiation dose of the lens can be reduced by moving the lens out of the field range by adjusting the table height and magnification ratio during the examination using 3D-RA. The surface dose was measured using a rando phantom and a radiophotoluminescent glass dosimeter (PLD) and the radiation dose was compared by adjusting the table height and magnification ratio based on the central point. As a result, it was found that the radiation dose of the lens decreased as the table height increased from the central point, that is, as the lens was out of the field of view. In conclusion, in 3D-RA, moving the table position of about 2 cm in height will make a significant contribution to the dose reduction of the lens, and it was confirmed that adjusting the magnification ratio can also reduce the surface dose of the lens.

• Journal of Radiation Protection and Research
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• 제49권1호
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• pp.1-18
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• 2024

Exponential growth has been observed in nuclear medicine procedures worldwide in the past decades. The considerable increase is attributed to the advance of positron emission tomography and single photon emission computed tomography, as well as the introduction of new radiopharmaceuticals. Although nuclear medicine procedures provide undisputable diagnostic and therapeutic benefits to patients, the substantial increase in radiation exposure to nuclear medicine patients raises concerns about potential adverse health effects and calls for the urgent need to monitor exposure levels. In the current article, model-based internal dosimetry methods were reviewed, focusing on Medical Internal Radiation Dose (MIRD) formalism, biokinetic data, human anatomy models (stylized, voxel, and hybrid computational human phantoms), and energy spectrum data of radionuclides. Key results from many articles on nuclear medicine dosimetry and comparisons of dosimetry quantities based on different types of human anatomy models were summarized. Key characteristics of seven model-based dose calculation tools were tabulated and discussed, including dose quantities, computational human phantoms used for dose calculations, decay data for radionuclides, biokinetic data, and user interface. Lastly, future research needs in nuclear medicine dosimetry were discussed. Model-based internal dosimetry methods were reviewed focusing on MIRD formalism, biokinetic data, human anatomy models, and energy spectrum data of radionuclides. Future research should focus on updating biokinetic data, revising energy transfer quantities for alimentary and gastrointestinal tracts, accounting for body size in nuclear medicine dosimetry, and recalculating dose coefficients based on the latest biokinetic and energy transfer data.

• Radiation Oncology Journal
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• 제36권4호
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• pp.332-340
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• 2018

Purpose: To retrospectively analyze dosimetric parameters of volumetric-modulated arc therapy (VMAT) and three-dimensional conformal radiotherapy (3D-CRT) delivered to extranodal marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue in the stomach (gastric MALT lymphoma) to find out advantages of VMAT and conditions for definite benefits of VMAT. Materials and Methods: Fifty patients with stage I-II gastric MALT lymphoma received VMAT (n = 14) or 3D-CRT (n = 36) between December 2005 and April 2018. Twenty-seven patients were categorized according to whether the planning target volume (PTV) overlaps kidney(s). Dosimetric parameters were analyzed by dose-volume histogram. Results: Radiation dose to the liver was definitely lower with VMAT in terms of mean dose (p = 0.026) and V₁₅ (p = 0.008). The V₁₅ of the left kidney was lower with VMAT (p = 0.065). For those with PTV overlapping kidney(s), the left kidney V₁₅ was significantly lower with VMAT. Furthermore, the closer the distance between the PTV and kidneys, the less the left kidney V₁₅ with VMAT (p = 0.037). Delineation of kidney(s) by integrating all respiratory phases had no additional benefit. Conclusions: VMAT significantly increased monitor units, reduced treatment time and radiation dose to the liver and kidneys. The benefit of VMAT was definite in reducing the left kidney V₁₅, especially in geometrically challenging conditions of overlap or close separation between PTV and kidney(s).

• Journal of Gynecologic Oncology
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• 제29권6호
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• pp.97.1-97.12
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• 2018

Objective: Women with cervical cancer (CC) found to have positive surgical margins, positive lymph nodes, and/or parametrial invasion receive a survival benefit from postoperative chemoradiotherapy (CRT) vs. radiation therapy (RT) alone. However, older women may not benefit to the same extent, as they are at increased risk of death from non-oncologic causes as well as toxicities from oncologic treatments. This study sought to evaluate whether there was a survival benefit of CRT over RT in elderly patients with cervical cancer. Methods: The National Cancer Database was queried for patients ${\geq}70$ years old with newly diagnosed IA2, IB, or IIA CC and positive margins, parametrial invasion, and/or positive nodes on surgical resection. Statistics included logistic regression, Kaplan-Meier overall survival (OS), and Cox proportional hazards modeling analyses. Results: Altogether, 166 patients met inclusion criteria; 62 (37%) underwent postoperative RT and 104 (63%) underwent postoperative CRT. Younger patients and those living in areas of higher income were less likely to receive CRT, while parametrial invasion and nodal involvement were associated with an increased likelihood (p<0.05 for all). There were no OS differences by treatment type. Subgroup analysis by number of risk factors, as well as each of the 3 risk factors separately, also did not reveal any OS differences between cohorts. Conclusion: In the largest such study to date, older women with postoperative risk factor(s) receiving RT alone experienced similar survival as those undergoing CRT. Although causation is not implied, careful patient selection is paramount to balance treatment-related toxicity risks with theoretical outcome benefits.

• 한국방사선학회논문지
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• 제16권4호
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• pp.463-470
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• 2022

본 연구의 목적은 공군 인력자원의 방사선에 대한 인식도를 분석하고자 하였다. 대상은 항공우주의료원에 방문한 공군 인력자원(군무원, 장교, 부사관, 병사) 남녀 259명이었다. 방법은 방사선 인식도 (위험성, 이익성, 관리성)에 대한 총 14문항의 설문지를 이용하여 조사연구로 진행 하였다. 통계적 분석은 독립표본 T-test와 일원분산분석(one-way analysis of variance, ANOVA)을 사용하여 집단 간의 유의한 차이를 확인하였다. 변수 간의 상관관계는 피어슨(Pearson) 및 스피어만(Spearman) 상관계수로 검정하였다. 그 결과, 방사선 위험성은 여성 공군 인력자원이 남성보다 유의하게 높은 인식도를 보였다. 방사선 이익성은 기혼자와 군무원, 장교, 부사관에서 유의하게 높았다. 방사선 관리성은 남자와 기혼자, 16년 이상의 군 경력자가 유의하게 높은 인식도를 가지고 있었다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권11호
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• pp.5741-5746
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• 2012

Aim: Although preoperative chemoradiatherapy (CRT) has proven its benefits in terms of decreased toxicity, there is still a considerable amount of cases that do not receive postoperative CRT. Oncologists at different geographic locations still need to know the long-term effects of this treatment in order to manage patients successfully. The current paper reports on long-term quality of life (QOL) and late side effects after adjuvant CRT in rectal cancer patients from 5 centers in Anatolia. Methods: Rectal cancer patients treated with postoperative CRT with minimum 1-year follow-up and were in complete remission, were evaluated according to RTOG and LENT-SOMA scales. They were also asked to complete Turkish version of EORTC QLQ-C30 questionnaire and the CR-38 module. Each center participated with the required clinical data. Results: Two hundred and thirty patients with median age of 55 years participated and completed the study. Median follow-up time was 5 years. All patients received RT concomitant with chemotherapy. Common parameters that both increased functional health scales and yielded better symptom scores were long term interval after treatment and sphincter-saving surgery. In addition, surgery type and follow-up time were determined to be predictors of QOL scores and late toxicity grade. Conclusion: Postoperative CRT was found to have a great impact on the long term QOL and side effects in rectal cancer survivors. The factors that adversely affect these are abdominoperineal resection and shorter interval. The findings may encourage life-long follow-up and cooperation with patients, which should be mentioned during the initial counseling.

• Journal of Radiation Protection and Research
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• 제18권1호
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• pp.71-82
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• 1993

원자력 발전소 작업과의 피폭량은 발전소의 안전 운영에 관한 척도일 뿐 아니라, 일반 대중이 원자력 발전의 안전을 평가하는 기본 요소이다. 또한, 최근 ICRP 60에 의한 개인 피폭선량 한도의 하향조정 권고는 지속적인 피폭저감에의 노력을 요구하고 있다. 본 논문에서는 작업자의 피폭저감에 관한 대안선정시 사용할 수 있는 최적화 기법을 제시하고 실제로 원전 운영자예 의해 제안된 대안들을 검토하는데 이 기법을 적용하여 보았다. 분석과정에서 기본분석이외에 가변 경제변수를 고려한 민감도 분석을 통해 계산 결과의 불확실성을 보완하였다. 분석결과를 살펴보면, 먼저 비용-이득 분석에서는 '증기 발생기 Nozzle Dam 및 Torquing Machine'이 총 이득면에서 가장 우수한 것으로 평가되었고, 다속성 효용 분석의 경우 'Co-No Seal 조임장치'가 가장 높은 효용을 가진 것으로 나타나 약간의 차이를 보이고 있다. 따라서, 최적화 기법의 적용시에는 두 가지이상의 정량적 기법을 보완적으로 사용하고, 정성적 인자도 충분히 고려하는 것이 필요하다.

• Radiation Oncology Journal
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• 제31권1호
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• pp.1-11
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• 2013

Purpose: Compared to conventional radiotherapy (RT), intensity-modulated radiotherapy (IMRT) significantly reduces the rate of treatment-induced late toxicities in head and neck cancer. However, a clear survival benefit of IMRT over conventional RT has not yet been shown. This study is among the first comparative study to compare the survival rates between conventional RT and helical tomotherapy in head and neck cancer. Materials and Methods: From January 2008 to November 2011, 37 patients received conventional RT and 30 patients received helical tomotherapy for management of head and neck cancer. We retrospectively compared the survival rates between patients treated with conventional RT and helical tomotherapy, and analyzed the prognostic factors for survival. Results: The 1- and 2-year locoregional recurrence-free survival rates were 61.2% and 58.1% for the conventional RT group, 89.3% and 80.3% for the helical tomotherapy group, respectively. The locoregional recurrence-free survival rates of the helical tomotherapy group were significantly higher than conventional RT group (p = 0.029). There were no significant differences in the overall and distant metastasis-free survival between the two groups. RT technique, tumor stage, and RT duration were significant prognostic factors for locoregional recurrence-free survival. Conclusion: This study showed the locoregional recurrence-free survival benefits of helical tomotherapy in the treatment of head and neck cancers.

• 한국콘텐츠학회논문지
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• 제13권9호
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• pp.281-287
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• 2013

본 연구는 부산광역시 거주민을 대상으로 배경 변인에 따라 방사선에 대한 지식, 지식수준의 지각, 방사선의 편익과 원자력 위험에 대한 인식, 그리고 후쿠시마 원전 사고 관련 정보수집과 인식 등은 어떻게 다른지를 알아보기 위한 목적으로 진행되었다. 분석을 위한 연구 대상은 414명의 거주민이다. 그 결과, 조사대상자들은 방사선의 필요성은 원칙적으로 인정하나 안전성에 대해서는 부정적인 인식을 가지고 있는 것으로 분석되었다. 이러한 부정적 인식은 방사선에 대한 지식을 기반으로 한 것이 아니라 과거 원전 사고 등에 기인한 것으로 판단되며, 향후 올바른 인식 전환을 위해서는 미디어를 통한 방사선과 원자력에 대한 교육과 홍보 그리고 방사선지식의 폭을 넓히고 나아가 보다 다양한 측면에서 시민들의 인식 변화를 위한 노력이 필요하다고 사료된다.