Study on Absorbed Dose Determination of Electron Beam Quality for Cross-calibration with Plane-parallel Ionization Chamber / 의학물리
Korean Journal of Medical Physics
;
: 97-105, 2009.
Article
in Korean
| WPRIM
| ID: wpr-115852
ABSTRACT
Absorbed dose to water based protocols recommended that plane-parallel chambers be calibrated against calibrated cylindrical chambers in a high energy electron beam with R50>7 g/cm2 (E> or =16 MeV). However, such high-energy electron beams are not available at all radiotherapy centers. In this study, we are compared the absorbed dose to water determined according to cross-calibration method in a high energy electron beam of 16 MeV and in electron beam energies of 12 MeV below the cross-calibration quality remark. Absorbed dose were performed for PTW 30013, Wellhofer FC65G Farmer type cylindrical chamber and for PTW 34001, Wellhofer PPC40 Roos type plane-parallel chamber. The cylindrical and the plane-parallel chamber to be calibrated are compared by alternately positioning each at reference depth, zref=0.6R50-0.1 in water phantom. The DW of plane-parallel chamber are derived using across-calibration method at high-energy electron beams of 16, 20 MeV. Then a good agreement is obtained the DW of plane-parallel chamber in 12 MeV. The agreement between 20 MeV and 12 MeV are within 0.2% for IAEA TRS-398.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Water
/
Electrons
Type of study:
Prognostic study
Language:
Korean
Journal:
Korean Journal of Medical Physics
Year:
2009
Type:
Article
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