Characteristics of Detectors for Measurements of Photon Depth Doses in Build-Up Region.
- Author:
Sei Kwon KANG
1
;
Byung Chul CHO
;
Suk Won PARK
;
Do Hoon OH
;
Hee Chul PARK
;
Su Ssan KIM
;
Hoonsik BAE
Author Information
1. Department of Radiation Oncology, College of Medicine, Hallym University, Korea. bychul@hallym.or.kr
- Publication Type:Original Article
- Keywords:
Build-up;
Electron contamination;
Ionization chamber;
Diode detector
- MeSH:
Water
- From:Korean Journal of Medical Physics
2005;16(2):77-81
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
To determine the appropriate method out of various available methods to measure build-up doses, the measurements and comparisons of depth doses of build-up region including the surface dose were executed using the Attix parallel-plate ionization chamber, the Markus chamber, a cylindrical ionization chamber, and a diode detector. Based on the measurements using the Attix chamber, discrepancies of the Markus chamber were within 2% for the open field and increased up to 3.9% in the case of photon beam containing the contaminant electrons. The measurements of an cylindrical ionization chamber and a diode detector accord with those of the Attix chamber within 1.5% and 1.0% after those detectors were completely immersed in the water phantom. The results suggest that the parallel-plate chamber is the best choice to measure depth doses in the build-up region containing the surface, however, using cylindrical ionization chamber or diode detector would be a reasonable choice if no special care is necessary for the exact surface dose.
