Wall‐correction and absorbed‐dose conversion factors for Fricke dosimetry: Monte Carlo calculations and measurements
作者:
Chang‐ming Ma,
D. W. O. Rogers,
K. R. Shortt,
C. K. Ross,
A. E. Nahum,
A. F. Bielajew,
期刊:
Medical Physics
(WILEY Available online 1998)
卷期:
Volume 20,
issue 2
页码: 283-292
ISSN:0094-2405
年代: 1998
DOI:10.1118/1.597128
出版商: American Association of Physicists in Medicine
数据来源: WILEY
摘要:
For megavoltage radiotherapy photon beams, EGS4 Monte Carlo calculations show, and experimental measurements confirm with an accuracy of 0.2%, that glass or quartz‐walled vials used in Fricke dosimetry increase the dose in the Fricke solution. This is mainly caused by increased electron scattering from the glass which increases the dose to the Fricke solution. The dose perturbation is shown to vary from nothing in a60Co beam up to 2% in a 24‐MV beam. For plastic vials of similar shapes, calculations demonstrate that the effect is in the opposite direction and even at high energies it is much less (0.2% to 0.5%).
点击下载:
PDF
(965KB)
返 回