Radiation Oncology Journal
- Volume 11 Issue 2
- /
- Pages.449-454
- /
- 1993
- /
- 2234-1900(pISSN)
- /
- 2234-3156(eISSN)
The Enhancement of Skin Sparing by Tray Materials for High Energy Photon Beam
고에너지 광자선치료에서 고정판 흡수물질을 이용한 피부보호효과의 향상
- Chu, Sung-Sil (Department of Radiation Oncology, College of Medicine, Yonsei University) ;
- Lee, Chang-Geol (Department of Radiation Oncology, College of Medicine, Yonsei University) ;
- Kim, Gwi-Eon (Department of Radiation Oncology, College of Medicine, Yonsei University)
- Published : 1993.12.01
Abstract
The skin sparing effect associated with high energy x-ray or gamma ray beams may be reduce or lost under certain conditions of treatment. Current trends in using large fields. Shield carrying trays, compensating filters, and isocentric methods of treatment have posed problems of increased skin dose which sometimes become a limiting factor in giving adquate tumor doses. We used the shallow ion chamber to measure the phantom surface dose and the physical treatment variables for Co-60 gamma ray, 4MV and 10 MV x-ray beam. The dependence of percent surface dose on field sizes, atomic number of the shielding tray materials and its distance from the surface for 4, 10MV x-rays and Co-60 gamma ray is qualitatively similar. The use of 2 mm thick tin filter is recommended for situations where a low atomic number tray is introduced into the beam at distances less than 15 cm from the surface and with the large field sized for 4 MV x-ray beam. In case of Co-60 gamma ray, the lead glass tray is suitable for enhancement of skin sparing. Also, the filter distance should be as large as possible to achieve substantial skin sparing.
종양치료를 위하여 고에너지 X-선 또는 감마선을 인체에 조사할 경우 피부 표면 선량이 최대지점 선량의