Influence of metallic dental implants and metal artefacts on dose calculation accuracy.
Strahlenther Onkol
; 191(3): 234-41, 2015 Mar.
Article
em En
| MEDLINE
| ID: mdl-25359507
ABSTRACT
PURPOSE:
Metallic dental implants cause severe streaking artefacts in computed tomography (CT) data, which inhibit the correct representation of shape and density of the metal and the surrounding tissue. The aim of this study was to investigate the impact of dental implants on the accuracy of dose calculations in radiation therapy planning and the benefit of metal artefact reduction (MAR). A second aim was to determine the treatment technique which is less sensitive to the presence of metallic implants in terms of dose calculation accuracy. MATERIALS ANDMETHODS:
Phantoms consisting of homogeneous water equivalent material surrounding dental implants were designed. Artefact-containing CT data were corrected using the correct density information. Intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) plans were calculated on corrected and uncorrected CT data and compared to 2-dimensional dose measurements using GafChromic™ EBT2 films.RESULTS:
For all plans the accuracy of dose calculations is significantly higher if performed on corrected CT data (p = 0.015). The agreement of calculated and measured dose distributions is significantly higher for VMAT than for IMRT plans for calculations on uncorrected CT data (p = 0.011) as well as on corrected CT data (p = 0.029).CONCLUSION:
For IMRT and VMAT the application of metal artefact reduction significantly increases the agreement of dose calculations with film measurements. VMAT was found to provide the highest accuracy on corrected as well as on uncorrected CT data. VMAT is therefore preferable over IMRT for patients with metallic implants, if plan quality is comparable for the two techniques.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Dosagem Radioterapêutica
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Tomografia Computadorizada por Raios X
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Artefatos
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Implantação Dentária Endóssea
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Metais
Limite:
Humans
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article