Shielding requirements in helical tomotherapy.

Details

Serval ID
serval:BIB_D36612961BF6
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Shielding requirements in helical tomotherapy.
Journal
Physics in Medicine and Biology
Author(s)
Baechler S., Bochud F.O., Verellen D., Moeckli R.
ISSN
0031-9155 (Print)
ISSN-L
0031-9155
Publication state
Published
Issued date
2007
Peer-reviewed
Oui
Volume
52
Number
16
Pages
5057-5067
Language
english
Notes
Publication types: Journal Article
Publication Status: ppublish
Abstract
Helical tomotherapy is a relatively new intensity-modulated radiation therapy (IMRT) treatment for which room shielding has to be reassessed for the following reasons. The beam-on-time needed to deliver a given target dose is increased and leads to a weekly workload of typically one order of magnitude higher than that for conventional radiation therapy. The special configuration of tomotherapy units does not allow the use of standard shielding calculation methods. A conventional linear accelerator must be shielded for primary, leakage and scatter photon radiations. For tomotherapy, primary radiation is no longer the main shielding issue since a beam stop is mounted on the gantry directly opposite the source. On the other hand, due to the longer irradiation time, the accelerator head leakage becomes a major concern. An analytical model based on geometric considerations has been developed to determine leakage radiation levels throughout the room for continuous gantry rotation. Compared to leakage radiation, scatter radiation is a minor contribution. Since tomotherapy units operate at a nominal energy of 6 MV, neutron production is negligible. This work proposes a synthetic and conservative model for calculating shielding requirements for the Hi-Art II TomoTherapy unit. Finally, the required concrete shielding thickness is given for different positions of interest.
Keywords
Computer-Aided Design, Equipment Design, Equipment Failure Analysis, Humans, Radiation Dosage, Radiation Injuries/prevention & control, Radiation Protection/instrumentation, Radiation Protection/methods, Radiometry/methods, Radiotherapy, Conformal/instrumentation, Radiotherapy, Conformal/methods, Scattering, Radiation
Pubmed
Web of science
Create date
25/04/2008 16:43
Last modification date
20/08/2019 15:53
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