Radiation Oncology Journal

The Korean Society for Radiation Oncology (대한방사선종양학회)
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Confirmation of the Dose Distribution by Stereotactic Radiosurgery Technique with a Multi-purpose Phantom

다용도 팬톰에서 정위방사선수술기법의 선량 정확도 확인

  • Yoo Hyung Jun (Department of Therapeutic Radiology, Institute of Radiation Medicine, Medical Research Center, Seoul National University College of Medicine) ;
  • Kim Il Han (Department of Therapeutic Radiology, Institute of Radiation Medicine, Medical Research Center, Seoul National University College of Medicine) ;
  • Ha Sung Whan (Department of Therapeutic Radiology, Institute of Radiation Medicine, Medical Research Center, Seoul National University College of Medicine) ;
  • Park Charn Il (Department of Therapeutic Radiology, Institute of Radiation Medicine, Medical Research Center, Seoul National University College of Medicine) ;
  • Hur Sun Nyung (Department of Therapeutic Radiology, Institute of Radiation Medicine, Medical Research Center, Seoul National University College of Medicine) ;
  • Kang Wee-Saing (Department of Therapeutic Radiology, Institute of Radiation Medicine, Medical Research Center, Seoul National University College of Medicine)
  • 유형준 (서울대학교 의과대학 치료방사선과학교실, 의학연구원 방사선의학연구소) ;
  • 김일한 (서울대학교 의과대학 치료방사선과학교실, 의학연구원 방사선의학연구소) ;
  • 하성환 (서울대학교 의과대학 치료방사선과학교실, 의학연구원 방사선의학연구소) ;
  • 박찬일 (서울대학교 의과대학 치료방사선과학교실, 의학연구원 방사선의학연구소) ;
  • 허순녕 (서울대학교 의과대학 치료방사선과학교실, 의학연구원 방사선의학연구소) ;
  • 강위생 (서울대학교 의과대학 치료방사선과학교실, 의학연구원 방사선의학연구소)
  • Published : 2002.06.01
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Abstract

Purpose : For the purpose of quality assurance of self-developed stereotactic radiosurgery system, a multi-purpose phantom was fabricated, and accuracy of radiation dose distribution during radiosurgery was measured using this phantom. Materials and Methods : A farmer chamber, a 0.125 cc ion chamber and a diode detector were used for the dosimetry. Six MV x-ray from a linear accelerator (CL2100C, Varian) with stereotactic radiosurgery technique (Green Knife) was used, and multi-purpose phantom was attached to a stereotactic frame (Fisher type). Dosimetry was done by combinations of locations of the detectors in the phantom, fixed or arc beams, gantry angles $(20^{\circ}\~100^{\circ})$, and size of the circular tertiary collimators (inner diameters of $10\~40\;mm$). Results : The measurement error was less than $0.5\%$ by Farmer chamber, $0.5\%$ for 0.125 cc ion chamber, and less than $2\%$ for diode detector for the fixed beam, single arc beam, and 5-arc beam setup. Conclusion : We confirmed the accuracy of dose distribution with the radiosurgery system developed in our institute and the data from this study would be able to be effectively used for the improvement of quality assurance of stereotactic radiosurgery or fractionated stereotactic radiotherapy system.

목적 : 본 교실에서 개발한 정위방사선수술 시스템의 정도관리를 위하여 다용도 팬톰을 제작하고 정위방사선수술 기법의 선량의 정확도를 확인하려 하였다. 대상 및 방법 : CL2100C 선형가속기에서 발생하는 6 MV 엑스선을 사용하여 정위적 방사선수술을 시행하였고 Farmer형 이온함, 0.125 cc 이온함, 다이오드 검출기 등을 정위 기준기구가 부착된 팬톰내에 설치한 후 선량을 측정하였다. 고정 빔, $20^{\circ}\~100^{\circ}$의 각도를 갖는 단일회전빔, 복합회전빔 등의 방사선조사 조건에서 측정기와 팬톰의 상대적 위치를 변화시키면서 측정하였다. 내경이 10, 20, 30, 40 mm인 원형의 3차 콜리메이터를 사용하였다. 결과 : 고정 빔, 단일 회전빔, 5개의 회전 빔으로 구성된 복합회전빔 등에서의 선량오차는 Farmer형 이온함으로 측정한 경우는 $0.5\%$ 이하, 0.125 cc 이온함의 경우에는 $0.5\%$, 다이오드 검출기인 경우에는 $2\%$ 이내였다. 결론 : 본 교실 개발 정위방사선수술 기법에 의한 방사선 조사선량의 정확도를 확인하였으며 이 자료는 향후 정위방사선수술 및 다분할 방사선치료의 정도관리에 유용한 기초자료로 활용될 것이다.

Keywords

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