Scattered photons produced by beam‐modifying filters
作者:
Pin‐Hua Huang,
Lee M. Chin,
Bengt E. Bjärngard,
期刊:
Medical Physics
(WILEY Available online 1998)
卷期:
Volume 13,
issue 1
页码: 57-63
ISSN:0094-2405
年代: 1998
DOI:10.1118/1.595923
出版商: American Association of Physicists in Medicine
数据来源: WILEY
摘要:
When a beam‐modifying filter such as a wedge or a compensator is placed in an x‐ray beam, scattered photons are generated in the filter material. The magnitude of the dose contribution from these photons for a 4‐MV x‐ray beam was measured. At a distance of 30 cm from the filter, a copper sheet of 1‐cm thickness produced a dose contribution on the centerline of about 6% of the transmitted primary dose in a 20×20 cm2field. At the edges of the beam, this contribution was only about one‐half that on the centerline. The presence of these scattered photons leads to only minor dose errors in clinical applications if simple procedures are followed to account for their contribution.
点击下载:
PDF
(547KB)
返 回