Development of 3-D Stereotactic Localization System and Radiation Measurement for Stereotactic Radiosurgery

방사선수술을 위한 3차원 정위 시스템 및 방사선량 측정 시스템 개발

  • 서태석 (가톨릭대학교 의과대학 방사선과학교실) ;
  • 서덕영 (경희대학교 공과대학 전자공학과) ;
  • 박승훈 (건국대학교 의과대학 의공학과) ;
  • 장홍석 (가톨릭대학교 의과대학 방사선과학교실) ;
  • 최보영 (가톨릭대학교 의과대학 방사선과학교실) ;
  • 윤세철 (가톨릭대학교 의과대학 방사선과학교실) ;
  • 신경섭 (가톨릭대학교 의과대학 방사선과학교실) ;
  • 박용휘 (가톨릭대학교 의과대학 방사선과학교실) ;
  • 김일환 (서울대학교 의과대학 치료방사선과학교실) ;
  • 강위생 (서울대학교 의과대학 치료방사선과학교실) ;
  • 하성환 (서울대학교 의과대학 치료방사선과학교실) ;
  • 박찬일 (서울대학교 의과대학 치료방사선과학교실)
  • Published : 1995.03.30

Abstract

The purpose of this research is to develop stereotactic localization and radiation measurement system for the efficient and precise radiosurgery. The algorithm to obtain a 3-D stereotactic coordinates of the target has been developed using a Fisher CT or angio localization. The procedure of stereotactic localization was programmed with PC computer, and consists of three steps: (1) transferring patient images into PC; (2) marking the position of target and reference points of the localizer from the patient image; (3) computing the stereotactic 3-D coordinates of target associated with position information of localizer. Coordinate transformation was quickly done on a real time base. The difference of coordinates computed from between Angio and CT localization method was within 2 mm, which could be generally accepted for the reliability of the localization system developed. We measured dose distribution in small fields of NEC 6 MVX linear accelerator using various detector; ion chamber, film, diode. Specific quantities measured include output factor, percent depth dose (PDD), tissue maximum ratio (TMR), off-axis ratio (OAR). There was small variation of measured data according to the different kinds of detectors used. The overall trends of measured beam data were similar enough to rely on our measurement. The measurement was performed with the use of hand-made spherical water phantom and film for standard arc set-up. We obtained the dose distribution as we expected. In conclusion, PC-based 3-D stereotactic localization system was developed to determine the stereotactic coordinate of the target. A convenient technique for the small field measurement was demonstrated. Those methods will be much helpful for the stereotactic radiosurgery.