Journal of radiological science and technology (대한방사선기술학회지:방사선기술과학)

Korean Society of Radiological Science (대한방사선과학회)
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A Study on the Dose Changes Depending on the Shielding Block Type of Irradiation During Electron Beam Theraphy

전자선치료 시 조사부위 차폐물 형태에 따른 선량변화 연구

  • Lee, Sun-Yeb (Department of Radiological Science, HALLYM COLLEGE) ;
  • Park, Cheol-Soo (Department of Radiological Science, HALLYM COLLEGE) ;
  • Lee, Jae-Seung (Department of Physics, Soonchunhyang University) ;
  • Goo, Eun-Hoe (Department of Physics, Soonchunhyang University) ;
  • Cho, Jae-Hwan (Department of Radiological Science, Gyeonesan University College) ;
  • Kim, Eng-Chan (Department of Physics, Yeungam University) ;
  • Moon, Soo-Ho (Department of Physics, Yeungam University) ;
  • Kim, Jin-Soo (Department of Radiation Oncology, Boondang CHA Hospital) ;
  • Park, Cheol-Woo (Department of Radiological Science, Dong-Eui Science College) ;
  • Dong, Kyung-Rae (Department of Radiological Science, Gwangju Health College) ;
  • Kweon, Dae-Cheol (Department of Radiological Science, Shinheung College)
  • Received : 2010.06.07
  • Accepted : 2010.09.06
  • Published : 2010.09.30
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Abstract

The primary focus of this study was to explore the variation in dose distributions of electron beams between different types of construction structure of cut-out blocks embodied in electron cones, given that the structure is considered one of the causes of multiple scattered radiation from electrons which may affect dose distributions. For evaluation, two types of cut-out blocks, divergency and straight, manufactured for this study, were compared in terms of area of interval in distribution of dose, and flatness and symmetric state of surface being radiated. The results showed that divergency cut-out blocks reduced the lateral scattering effects on the thickness of cut-out blocks more substantially than straight ones, leading to more uniform dose distribution at baseline depth. Notably in divergency cut-out blocks, the high dose area decreased more significantly, and more uniform dose distribution was observed at the edge of the irradiated field. This points to a need to consider the characteristics of dose distribution of electron beams when setting up radiotherapy planing at the venues. Therefore, this study is significant as an exploratory work for ensuring high accuracy in dose delivery for patients.

전자의 다중산란에 의한 선량분포를 좌우하는 다양한 원인으로서 조사통에 삽입되는 차폐물의 제작형태에 따른 전자선의 선량분포를 알고자 하였다. 실험을 위하여 선속 확산현상을 고려한 차폐물(divergency cut-out block)과 선속 확산현상을 고려하지 않은 차폐물(straight cut-out block)을 제작하고 선량분포 구간 면적과 조사면 평탄도 및 대칭도를 비교하였다. 결과적으로 선속 확산현상을 고려한 차폐물이 선속 확산현상을 고려하지 않은 차폐물보다 차폐물 두께에 대한 측방산란효과가 현저하게 감소함으로서 기준점 깊이에서 균등한 선량분포를 이루었다. 특히 선속 확산현상을 고려한 차폐물일수록 고 선량 영역이 현저하게 감소하였으며 조사면 경계부에서 균일한 선량분포를 이루었다. 이는 환자의 투여선량의 정확도를 증가시키기 위한 모형 연구로서 전자선의 선량분포 특성을 고려한 방사선치료계획을 수립해야 할 것이다.

Keywords

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