• 제목/요약/키워드: Radiation Dosimetry

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Postal Dosimetry Audits for the Domestic Medical Linear Accelerator

  • Kim, Kum Bae;Choi, Sang Hyoun
    • 한국의학물리학회지:의학물리
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    • 제31권2호
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    • pp.20-28
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    • 2020
  • Purpose: The objective of this study is to perform Postal dosimetry audits for medical linear accelerators in radiation therapy institutions using glass dosimeters and Gafchromic film reading systems and postal dosimetry audit procedures, and to evaluate radiation therapy doses and mechanical accuracy in medical institutions. Methods: Photon output measured and analyzed using a standard phantom for measuring photon output dose using a glass dosimeter for medical linear accelerators. Mechanical accuracy was measured and analyzed using software for film measurement. Results: Measurement and analysis of photon beam output dose using a standard phantom glass dosimeter for photon beam output dose measurement was completed. All tolerance doses were within 5%. Mechanical accuracy measurement and analysis using a standard phantom for verifying the mechanical accuracy of linear accelerator (LINAC) using a Gafchromic film were completed, and all results were shown within tolerances (2 mm or less). Conclusions: In this study, Postal dosimetry audits were performed on the output dose and mechanical accuracy of photon beams (207 beams) for 106 LINACs from 48 institutions. As a result of corrective action and re-execution, it was confirmed that all engines met the acceptable standard within 2 mm in the linear accelerator.

고에너지 방사선치료에서 차폐물 경계부위의 선량분포에 관한 고찰 (A Study on the dosimetry in boundary of shielding block in high energy irradiation)

  • 김명세;김성규;신세원
    • Journal of Yeungnam Medical Science
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    • 제7권2호
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    • pp.115-120
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    • 1990
  • 18MeV 선형가속기와 코발트 원격치료기를 사용하여 방사선 조사면적 내에 차폐물이 있는 경우, 차폐물에 의한 산란선이 선량분포에 미치는 영향에 관하여 고찰하여 다음과 같은 결과를 얻었다. 1. 차폐물이 이루는 각이 예각일수록 산란선의 효과는 더 크게 나타났다. 2. 차폐물의 넓이가 좁을수록 산란선의 효과는 더 크게 나타났다. 3. 조사면적에 따른 출력특성은 선형적이지만, 차폐물에 의한 출력특성은 조사면적에 대하여 선형가속기는 거의 무관하게 나타났으며, 코발트 원격치료기는 기울기가 적은 선형성을 나타내었다.

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In Vivo Dosimetry with MOSFET Detector during Radiotherapy

  • Cho, Sam-Ju;Kim, Won-Taek;Ki, Yong-Gan;Kwon, Soo-Il;Lee, Sang-Hoon;Huh, Hyun-Do;Cho, Kwang-Hwan;Kwon, Byung-Hyun;Kim, Dong-Won
    • 한국의학물리학회:학술대회논문집
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    • 한국의학물리학회 2006년도 제33회 추계학술대회 발표논문집
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    • pp.85-85
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    • 2006
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관전압(管電壓)과 조사야(調査野) 및 피사체(被寫體)의 변화에 따른 선량분포(線量分布) (Dosimetry according to the X-ray Tube Voltage, Radiation Field and the Object Thickness)

  • 이상석;박성옥
    • 대한방사선기술학회지:방사선기술과학
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    • 제3권1호
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    • pp.73-80
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    • 1980
  • We studied about dosimetry according to the X-ray tube voltage, radiation field object thickness and obtained results as follow. 1. Secondary ray involing rate in the penetrated radiation increased proportion to the tube voltage, but its rate is more larger at the small radiation fields. than large fields. 2. Secondary ray involving rate in the penetrated radiation increased at thick object and large exposure fields. But saturated phenomenon appeared at limited field. 3. Secondary involving rate of acryl phantom is more top place than water, paraffin and aluminum phantom.

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Retrospective dosimetry using fingernail electron paramagnetic resonance response

  • Noori, Abbas;Mostajaboddavati, Mojtaba;Ziaie, Farhood
    • Nuclear Engineering and Technology
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    • 제50권3호
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    • pp.526-530
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    • 2018
  • Human fingernails were used to estimate the radiation dose via electron paramagnetic resonance measurements of radiation-induced radicals. The limiting factors in this research were mechanically induced electron paramagnetic resonance signals due to the mechanical stress during the preparation of the samples. Therefore, different treatment methods of fingernails were used to reduce the mechanically induced signals. The results demonstrate that the mechanically induced and radiation-induced signals have apparently different microwave power saturation behaviors. In addition, the mechanically induced signal shows a fading evolution over time and reaches a constant value. Chemical treatment using the different reagents showed that the minimum mechanically induced signal was obtained using the dithiothreitol reagent. The dose-response curves of the samples treated with dithiothreitol for 30 minutes demonstrated a greater linearity than those of samples treated for 5 minutes. Therefore, to find an unknown absorbed dose in a fingernail sample using a calibration curve, we recommend adopting the mentioned chemical treatment procedure to reduce the uncertainty.

Formulation of a New En Score in the Proficiency Test

  • Chul-Young Yi;In Jung Kim;Jong In Park;Yun Ho Kim;Young Min Seong
    • 한국의학물리학회지:의학물리
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    • 제35권1호
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    • pp.16-19
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    • 2024
  • A new En score of the proficiency test (PT) is formulated; it is applicable when a correlation exists between the reference and participant's values. Based on the uncertainty propagation rule given in ISO/IEC Guide 98-3 (GUM:1995), the En score covering the correlation case is newly developed for the PT. The new En score will be applied in a future PT organized by the Korea Research Institute of Standards and Science (KRISS) dosimetry team. The new En score will enhance measurement traceability and contribute to improving the quality management system of participants in the KRISS PT by avoiding performance underestimation.