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Test procedures for...
Test procedures for verification of an electron pencil beam algorithm implemented for treatment planning
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- Blomquist, M (författare)
- Umeå universitet,Radiofysik
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- Karlsson, Mikael (författare)
- Umeå universitet,Radiofysik
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(creator_code:org_t)
- Elsevier BV, 1996
- 1996
- Engelska.
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 39:3, s. 271-286
- Relaterad länk:
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https://urn.kb.se/re...
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https://doi.org/10.1...
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Abstract
Ämnesord
Stäng
- The calculation of an electron dose distribution in a patient is a difficult problem because of the presence of tissue and surface inhomogeneities. Verification of the dose planning system is therefore essential. In this investigation, a novel method is used to evaluate a commercially available system (Helax-TMS), at electron energies between 10 and 50 MeV, both for a conventional treatment unit and an MLC-collimated scanned beam unit with a helium-filled treatment head. First, the experiments were designed to verify the local beam database and some fundamental characteristics of the electron beam calculations. Secondly, a number of generalised situations that would be encountered in the clinical treatment planning were evaluated: oblique incidence, field shaping with multi-leaf collimator, bolus edges, and air cavities. Dose distributions in two generalised anatomical phantoms simulating a neck and a nose were also analysed. The results have, when so possible, been presented as the dose ratio within the 'flattened area' for dose profiles and down to the 'treatment depth' (80% dose level) for depth doses. In the penumbra region and in the dose fall-off region, the comparison has been represented by the distance deviation between calculated and measured dose profiles or depth doses. A new tool, 'volume integration', was used to evaluate the deviations from a more clinical point of view. Most results were within +/-2% in dose for volumes larger than a sphere with a diameter of 15 mm, or +/-2 mm in position. Dose deviations were generally found for oblique incidences and below heterogeneities such as small air cavities and bolus edges in limited volumes.
Nyckelord
- Electron beams; Algorithm verification; Treatment planning; Inhomogeneities
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
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