• Title/Summary/Keyword: Radioactive dose

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Spect-guidance to Reduce Radioactive Dose to Functioning Lung for Stage III Non-small Cell Lung Cancer

  • Wang, Zhong-Tang;Wei, Li-Li;Ding, Xiu-Ping;Sun, Ming-Ping;Sun, Hong-Fu;Li, Bao-Sheng
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.2
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    • pp.1061-1065
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    • 2013
  • Objective: To investigate the treatment effect of additional information obtained by single photon emission computed tomography (SPECT) lung perfusion imaging (LPI) in the radiotherapy planning process for patients with stage III non-small cell lung cancer (NSCLC). Methods: 39 patients with stage III NSCLC were enrolled. Gross tumor volume (GTV) was outlined by SPECT/CT images, SPECT-LPIs being used to define functional lung (FL) and non-functional lung (NFL) regions. Two sets of IMRT plans were designed to deliver 64Gy to PTV. One was a regular IMRT plan using CT images only (Plan 1), and the other was a corresponding IMRT plan using co-registered images (Plan 2). $FL_{Vx}$ (the % volume of functional lung receiving ${\geq}$x Gy) and $WL_{Vx}$ (% volume of whole lung to receive ${\geq}$x Gy) were compared by paired Student's t test. Kendalls correlation was used to analyze the factor (s) related with the FLV20 decrease. Results: Compared with plan 1, both $WL_{Vx}$ and $FL_{Vx}$ were decreased in plan 2. $WL_{V10}$, $WL_{V15}$, $WL_{V20}$, $WL_{V25}$, $WL_{V30}$ and $WL_{V35}$ decreased 9.7%, 13.8%, 17.2%, 12.9%, 9.8% and 9.8%, and $FL_{V10}$, $FL_{V15}$, $FL_{V20}$, $FL_{V25}$, $FL_{V30}$ and $FL_{V35}$ decreased 10.8%, 14.6%, 17.3%, 14.5%, 14.5% and 10.5%. $FL_{Vx}$ decreased significantly compared with $WL_{Vx}$. There were significant differences in $WL_{V10}$, $WL_{V15}$, $WL_{V20}$, $WL_{V25}$, $WL_{V3}$ and $FL_{V10}$, $FL_{V15}$, $FL_{V20}$, $FL_{V25}$, $FL_{V30}$ between plan 1 and plan 2 (P=0.002, 0.000, 0.000, 0.005, 0.027 and 0.002, 0.000, 0.000, 0.006, 0.010). According to Kendall correlation analysis, NFL had a negative relation with the percentage FLV20 decrease (r=-0.559, P<0.01), while the distance of PTV and NFL center had a significantly positive relation with the percentage of FLV20 decrease (r=0.768, P<0.01). Conclusion: Routine use of SPECT-LPI for patients undergoing radiotherapy planning for stage III NSCLC appears warranted.

Influence of the Monitoring Interval and Intake Pattern for the Evaluation of Intake (내부피폭 감시주기 및 섭취형태가 방사성핵종 섭취량 평가에 미치는 영향)

  • Jong-Il Lee;Tae-Young Lee;Si-Young Chang;Jai-Ki Lee
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.2 no.1
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    • pp.53-59
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    • 2004
  • A variety of factors such as the pattern of intake (acute or chronic), monitoring interval and the characteristics of the radionuclides could have a significant influence on the estimates for the intake and internal dose. The relative differences of the assessed intakes based on the assumption of an acute intake to that of a chronic intake were evaluated by using the predicted bioassay quantity in the whole body or organs for an acute and chronic intake through the inhalation of $^{125}$ I, $^{137}$ C, $^{235}$ U with the AMAD of 1 ${\mu}{\textrm}{m}$ and 5 ${\mu}{\textrm}{m}$ for the monitoring intervals of 7, 14, 30, 60, 90, 120, 180, 360 days, respectively, The relative difference of the assessed intakes based on the intake pattern is affected by the monitoring interval, radionuclide and absorption type, but the particle size has little influence on the difference of the assessed intakes based on the intake pattern. The maximum monitoring interval, which is defined as the monitoring interval that the relative difference of the assessed intakes based on the assumption of an acute intake to that of a chronic intake is less than 10%, is 60 d for $^{125}$ I with Type F, 180 d for $^{137}$ C with Type F, 90 d for $^{235}$ U with Type M, and 360 d for $^{235}$ U with Type S. It was concluded that an intake pattern has little influence on the estimates of the assessed intake in the case where the monitoring interval is shorter than the maximum monitoring interval for each radionuclide.

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Comparison of Lung Ventilation Scan Using Technegas and $^{99m}Tc-DTPA$ Aerosol (Technegas 환기스캔과 $^{99m}Tc-DTPA$ Aerosol 스캔의 비교)

  • Choi, Yoon-Ho;Kim, Sang-Eun;Lee, Dong-Soo;Chung, June-Key;Lee, Myung-Chul;Kim, Keun-Youl;Koh, Chang-Soon;Koong, Sung-Soo
    • The Korean Journal of Nuclear Medicine
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    • v.24 no.2
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    • pp.237-243
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    • 1990
  • Pulmonary embolism demands rapid and accurate diagnosis. And ventilation imaging has greatly improved the diagnostic accuracy of pulmonary embolism in addition to perfusion imaging. Agents currently used include xenon-133, krypton-81m and technetium-99m radioaerosols. However radioactive gases are compromised by availability and cost for krypton-81m, radiation dose, gamma energy and non?physiologic behaviour for xenon-133. Radioaerosols of technetium-99m componds are rapidly cleared from the lung after inhalation, and their relative low effeciency (specific radioactivity) and wide distribution of particle sizes make them also suboptimum. A new ventilation agent, Technegas is a suspension of structured graphite ellipsoids with diameter below 20nm, labelled with $^{99m}Tc$ in a carrier gas of Argon. This report describes the authors' clinical experience with Technegas. This is the first reported clinical study of this agent in Korea. A comparison of Technegas and $^{99m}Tc-DTPA$ aerosol was performed in 12 patients with various pulmonary diseases such as COPD, pulmonary tuberculosis and pleural effusion. All patients were studied with $^{99m}Tc-DTPA$ aerosol inhalation and Technegas ventilation. In both studies image quality was assessed (1) semiquantitatively by scoring bronchial and gastric activity, (2) subjectively by direct visual comparison of peripheral lung images and (3) quantitatively by computing the peripheral penetration index(PI) for each lungs. The bronchial activites were seen in 7 out of 12 cases with $^{99m}Tc-DTPA$ aerosol and in 5/12 with Technegas. The gastric activities were seen in 5/12 and 1/12 cases respectively. The average values of PI were 61.26% with $^{99m}Tc-DTPA$ aerosol and 69.20% with Technegas (p>0.05). Using $^{99m}Tc-DTPA$ aerosol, COPD patients showed deposition in the central airways with poor visualization of the peripheral areas of the lungs. In Technegas studies these phenomena were less prominent, and the examination is well tolerated by pateients and requires only a minimum of patient cooperation. With superiority of easy availability and handling, better physical characteristics and favorable Image quality, Technegas is a Promising agent for lung ventilation scanning.

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A Sensitivity Study on Nuclide Release from the Near-field of the Pyroprocessed Waste Repository System: Part 1. A Probabilistic Approach (파이로처리 폐기물 처분 시스템 근계 영역 내 핵종 유출 민감도: 제 1 부 확률론적 접근)

  • Lee, Youn-Myoung;Jeong, Jongtae
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.12 no.1
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    • pp.19-35
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    • 2014
  • A parametric sensitivity to the annual exposure dose rate to the farming exposure group has been probabilistically carried out for three principal elements associated with the nuclide transport behavior in the near-field of the pyroprocessed waste repository system. Credit time for both metal and ceramic containers, annual nuclide release rete, and the degree of loss of bentonite buffer around the container are selected as the elements and investigated for important nuclides. All the elements are shown to be sensitive to the results. Methodology studied through this study and the results are expected to make a good feedback to the repository design. As a follow-up study, separated in Part 2, the A-KRS will be deterministically assessed and then compared among each other with the normal, the worst, and the best case scenarios associated with their extreme values these elements could have.

Radiological Risk Assessment for $^{99m}Tc$ Generator using Uncertainty Analysis (불확실성 분석을 이용한 $^{99m}Tc$ 발생기 사용의 방사선위험도 평가)

  • Jang, H.K.;Kim, J.Y.;Lee, J.K.
    • Journal of Radiation Protection and Research
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    • v.29 no.2
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    • pp.129-139
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    • 2004
  • Recently, much attentions are paid to the risk associated with increased uses of medium size radiation sources in medical and industrial fields. In this study, radiation risks to the worker and to the general public due to $^{99m}Tc$ generator were assessed for both normal and accident conditions. Based on the event tree technique, exposure scenarios for various situations were derived. Uncertainty analysis based on the Monte-Carlo technique was applied to the risk assessment for workers and members of the public in the vicinity of the work place. In addition, sensitivity analysis was performed on each of the five independent input parameters to identify importance of the parameters with respect to the resulting risk. Because the frequencies of normal tasks are fat higher than those of accidents, the total risk associated with normal tasks were higher than the accident risk. The annual dose due to normal tasks were $0.6mSv\;y^{-1}$ for workers and $0.014mSv\;y^{-1}$ for public, while in accident conditions $3.96mSv\;y^{-1}\;and\;0.0016mSv\;y^{-1}$, respectively. Uncertainty range of accident risk was higher by 10 times than that of normal risk. Sensitivity analysis revealed that source strength, working distance and working time were crucial factors affecting risk. This risk analysis methodology and its results will contribute to establishment of risk-informed regulation for medium and large radioactive sources.

EPMA Analysis of Inter-reaction Layer in Irradiated U3Si-Al Fuels (EPMA를 이용한 U3Si/Al 조사 핵연료의 반응층 분석)

  • Jung, Yang-Hong;Yoo, Byung-Ok;Kim, Hee-Moon;Park, Jong-Man;Kim, Myung-Han
    • Analytical Science and Technology
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    • v.17 no.4
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    • pp.355-362
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    • 2004
  • Fission products and Inter reaction layer of $U_3Si-Al$ dispersion fuel, irradiated in HANARO research reactor with 121 kW/m of maximum liner power and 63 at% of average burn-up, was characterization by EPMA (Electron Probe Micro Analyzer). The fuel punching system developed by Irradiated Materials Examination Facility (IMEF) has used to make these samples for the EPMA. With this system a very small and thin specimen which is 1.57 mm in diameter and 2 mm in thickness respectively has been fabricated to protect the EPMA operator from high radioactive fuel and to mini-mize the equivalent dose rate less than 150 mSv/h. EPMA was performed to observe layers of sectional, Inter-reaction and oxide with specimens of cutting and polished. Stoichiometry in the Inter-reaction layer with $16{\mu}m$ of thickness was $U_{2.84}$ Si $Al_{14}$ with calibration of $UO_2$ and $U_{3.24}$ Si $Al_{14.1}$ with calibration of standard specimen. metallic precipitates in this layer were not observed using fission products examination.

State-of-Arts of Primary Concrete Degradation Behaviors due to High Temperature and Radiation in Spent Fuel Dry Storage (사용후핵연료 건식저장 콘크리트의 고열과 방사선으로 인한 주요 열화거동 분석)

  • Kim, Jin-Seop;Kook, Donghak;Choi, Jong-Won;Kim, Geon-Young
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.16 no.2
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    • pp.243-260
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    • 2018
  • A literature review on the effects of high temperature and radiation on radiation shielding concrete in Spent Fuel Dry Storage is presented in this study with a focus on concrete degradation. The general threshold is $95^{\circ}C$ for preventing long-term degradation from high temperature, and it is suggested that the temperature gradient should be less than $60^{\circ}C$ to avoid crack generation in concrete structures. The amount of damage depends on the characteristics of the concrete mixture, and increases with the temperature and exposure time. The tensile strength of concrete is more susceptible than the compressive strength to degradation due to high temperature. Nuclear heating from radiation can be neglected under an incident energy flux density of $10^{10}MeV{\cdot}cm^{-2}{\cdot}s^{-1}$. Neutron radiation of >$10^{19}n{\cdot}cm^{-2}$ or an integrated dose of gamma radiation exceeding $10^{10}$ rads can cause a reduction in the compressive and tensile strengths and the elastic moduli. When concrete is highly irradiated, changes in the mechanical properties are primarily caused by variation in water content resulting from high temperature, volume expansion, and crack generation. It is necessary to fully utilize previous research for effective technology development and licensing of a Korean dry storage system. This study can serve as important baseline data for developing domestic technology with regard to concrete casks of an SF (Spent Fuel) dry storage system.

Non-clinical Trials using 14C-Acetaminophen to Validate Biomedical Accelerator Mass Spectrometry System (14C-아세트아미노펜 비임상시험을 통한 생체시료 분석용 가속질량분석기의 검증)

  • Jinho Song;Jae Hoon Shim;Jung Bae Park;Chang Su Yeo;Soo Hyeon Bae;Min Sun Choi;Mi Hye Kwon;Kyeong Min Kim
    • Journal of Radiation Industry
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    • v.17 no.2
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    • pp.127-134
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    • 2023
  • Pharmacokinetic (PK) data provide pivotal information in drug development, and they are usually first studied in the preclinical stage using various animals. However, quite often, animal PK data may not match with human PK, especially in metabolites. Thus, most regulatory agencies in the world make it mandatory to obtain metabolite information using 14C radiolabeled drug in human for small molecule drug candidates. However, such studies are expensive and time consuming and they are usually done at the end of Phase II trials using ~3.7 MBq of 14C labeled drug in a limited number of human subjects. Introduction of accelerator mass spectrometry (AMS) in this kind of study has revolutionized it. Since AMS can measure 14C level as close as natural abundance, it can quantify the amounts of 14C labeled drugs and their metabolites produced in human body that consumes less than the amount of 0.0037 MBq of 14C labeled drug, a very safe level of radioactive dose in human. Therefore, it is now possible to conduct human 14C studies safely in early clinical trials without spending hefty amount of money and time. Korea Radioisotope Center for Pharmaceuticals(KRICP) at Korea Institute of Biological and Medical Sciences(KIRAMS) has established an AMS facility in 2018, housing a 0.5MV AMS manufactured at the US National Electrostatics Corps (NEC). The AMS instrument has been validated using various standard samples that have been prepared at Lawrence Livermore National Laboratory in the US, a worldly reputable provider of AMS standards. In this paper, we present a mass balance study for acetaminophen in rats using AMS and prove that the study results are equivalent with those of literature, which shows the AMS facilities at KRICP has successfully installed and be ready to be used in the various PK studies using 14C labelled compounds for new drug development.

Development of Spent Nuclear Fuel Transportation Worker Exposure Scenario by Dry Storage Methods (건식 저장방식별 사용후핵연료 운반 작업자 피폭시나리오 개발)

  • Geon Woo Son;Hyeok Jae Kim;Shin Dong Lee;Min Woo Kwak;Kwang Pyo Kim
    • Journal of Radiation Industry
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    • v.18 no.1
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    • pp.43-52
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    • 2024
  • Currently, there are no interim storage facilities and permanent disposal facilities in Korea, so all spent nuclear fuels are temporarily stored. However, the temporary storage facility is approaching saturation, and as a measure to this, the 2nd Basic Plan for the Management of High-Level Radioactive Waste presented an operation plan for dry interim storage facilities and dry temporary storage facilities on the NPP on-site. The dry storage can be operated in various ways, and to select the optimal dry storage method, the reduction of exposure for workers must be considered. Accordingly, it is necessary to develop a worker exposure scenario according to the dry storage method and evaluate and compare the radiological impact for each method. The purpose of this study is to develop an exposure scenario for workers transporting spent nuclear fuel by dry storage method. To this end, first, the operation procedure of the foreign commercial spent nuclear fuel dry storage system was analyzed based on the Final Safety Analysis Report (FSAR). 1) the concrete overpack-based system, 2) the metal overpack-based system, and 3) the vertical storage module-based system were selected for analysis. Factors were assumed that could affect the type of work (working distance, working hours, number of workers, etc.) during transportation work. Finally, the work type of the processes involved in transporting spent nuclear fuel by dry storage method was set, and an exposure scenario was developed accordingly. The concrete overpack method, the metal overpack method, and the vertical storage module method were classified into a total of 31, 9, and 23 processes, respectively. The work distance, work time, and number of workers for each process were set. The product of working hours and number of workers (Man-hour) was set high in the order of concrete overpack method, vertical storage module method, and metal overpack method, and short-range work (10 cm) was most often applied to the concrete overpack method. The results of this study are expected to be used as basic data for performing radiological comparisons of transport workers by dry storage method of spent nuclear fuel.

Analysis of Residual Solvents of [F-18]FDG Using Gas Chromatography (기체크로마토그래프법을 이용한 [F-18]FDG의 잔류용매 분석)

  • Kim, Dong-Il;Lee, Il-Jung;Kim, Shi-Hwal;Chi, Yong-Gi;Seok, Jae-Dong
    • The Korean Journal of Nuclear Medicine Technology
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    • v.15 no.2
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    • pp.26-29
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    • 2011
  • Purpose: The general test method of the Korean Pharmacopeia specifies the test method on the clauses of quality control after manufacturing. According to KFDA Guidance for Medicines, standards of residual solvents regulates the maximum permissible dose of acetonitrile as 400 ppm, ethanol as 5,000 ppm, and acetic acid as 5,000 ppm. This study aims at identifying the type of resiual solvents in the final [F-18]FDG vial of an automatic synthesizer and measure its residual quantity. Materials and Methods: The center carried out residual solvents test of [F-18]FDG injection using Agilent Technologies 7890A with a Flame Ionization Detector. The column of Agilent Technologies 7890A used in measuring of residual solvents was CP WAX column ($30m{\times}0.53mm{\times}1.0{\mu}m$) and analysis condition was split mode 1:1 at the initial temperature $70^{\circ}C$ which was increased $20^{\circ}C/minute$ after two minutes and maintained at the final $140^{\circ}C$ for two minutes. The analysis method was as following: Firstly, ethanol-acetonitrile-acetic acid mixture was classified into four types of concentration (250-25-250 ppm, 1,000-100-1,000 ppm, 3,000-300-3,000 ppm, and 6,000-600-6,000 ppm), and $1.0{\mu}L$ of each type of concentration was injected into gas chromatography followed by an analysis of its peak domain. Then, a calibration-curve by the external standard method was drawn based on the analysis result. Results: While ethanol and acetonitrile were detected in TRACERlab MX, FASTlab had additional acetic acid. The residual quantity of the ethanol-acetonitrile-acetic acid mixture evaluated using the calibration-curve was average 72 ppm ethanol, 54 ppm acetonitrile, and 1030 ppm acetic acid for FASTlab, whereas average 439 ppm ethanol and 79 ppm acetonitrile for TRACERlab MX. This indicated that both of them were within the maximum permissible dose. Conclusion: Solvent residues in the [F-18]FDG injection were all within maximum permissible doses and proper to be used to examine a patient. The result indicated that types and quantities of solvent resides of radioactive pharmaceuticals vary depending on the automatic synthesizer.

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