Progress in Medical Physics (한국의학물리학회지:의학물리)

Korean Society of Medical Physics (한국의학물리학회)
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Quality Correction for Ir-192 Gamma Rays in Air Kerma Strength Dosimetry Using Cylindrical Ionization Chambers

원통형 전리함을 이용한 Ir-192 선원에 대한 공기커마세기 측정 시 선질보정에 관한 연구

  • Jeong, Dong-Hyeok (Department of Radiation Oncology, School of Medicine, Wonkwang University) ;
  • Kim, Jhin-Kee (Research Institute of Clinical Medicine, Chonbuk National University) ;
  • Kim, Ki-Hwan (Department of Radiation Oncology, Chungnam National University Hospital) ;
  • Oh, Young-Kee (Department of Radiation Oncology, Keimyung University Dongsan Medical Center) ;
  • Kim, Soo-Kon (Department of Radiation Oncology, Kangwon University Hospital) ;
  • Lee, Kang-Kyoo (Department of Radiation Oncology, School of Medicine, Wonkwang University) ;
  • Moon, Sun-Rock (Department of Radiation Oncology, School of Medicine, Wonkwang University)
  • 정동혁 (원광대학교 의과대학병원 방사선종양학과) ;
  • 김진기 (전북대학교 임상의학연구소) ;
  • 김기환 (충남대학교병원 방사선종양학과) ;
  • 오영기 (계명대학교 동산병원 방사선종양학과) ;
  • 김수곤 (강원대학교병원 방사선종양학과) ;
  • 이강규 (원광대학교 의과대학병원 방사선종양학과) ;
  • 문성록 (원광대학교 의과대학병원 방사선종양학과)
  • Published : 2009.03.31
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Abstract

The quality correction in the air kerma dosimetry for Ir-192 using farmer type ionization chambers calibrated by Co-60 quality is required. In this study we determined quality factor ($k_u$) of two ionization chambers of PTW-N30001 and N23333 for Ir-192 source using dosimetric method. The quality factors for energy spectrum of microSelectron were determined as $k_u$=1.016 and 1.017 for PTW-N30001 and N23333 ionization chambers respectively. We applied quality factors in air kerma dosimetry for microSelectron source and compared with reference values. As a results we found that the differences between reference air kerma rate and measured it with and without quality correction were about -0.5% and -2.0% respectively.

Co-60 선원에 대해 교정된 원통형 전리함 이용하여 Ir-192 선원에 대한 공기커마세기를 측정하는 경우에 선질 차이에 대한 보정이 필요하다. 본 연구에서는 측정학적 방법을 적용하여 PTW-N30001과 N23333 전리함에 대하여 Ir-192 감마선에 대한 선질 인자를 결정하였다. Ir-192 선원(microSelectron)의 에너지스펙트럼을 적용할 경우에 선질인자($k_u$)는 두 전리함에 대해 각각 $k_u$=1.016 (N30001)과 $k_u$=1.017 (N23333)으로 계산되었다. 치료용 microSelectron 선원에 대해 선질 인자를 적용하여 공기커마 세기를 측정하였으며 결과를 기준값과 비교하였다. 결과적으로 선질인자를 적용하는 경우에 기준 공기커마율과 약 -0.5% 이내의 차이를 보였으며 적용하지 않는 경우에는 약 -2.0%의 차이를 보였다.

Keywords

References

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