Iterative metal artifact reduction improves dose calculation accuracy : Phantom study with dental implants.
Strahlenther Onkol
; 192(6): 403-13, 2016 Jun.
Article
em En
| MEDLINE
| ID: mdl-26968180
ABSTRACT
PURPOSE:
Metallic dental implants cause severe streaking artifacts in computed tomography (CT) data, which affect the accuracy of dose calculations in radiation therapy. The aim of this study was to investigate the benefit of the metal artifact reduction algorithm iterative metal artifact reduction (iMAR) in terms of correct representation of Hounsfield units (HU) and dose calculation accuracy. MATERIALS ANDMETHODS:
Heterogeneous phantoms consisting of different types of tissue equivalent material surrounding metallic dental implants were designed. Artifact-containing CT data of the phantoms were corrected using iMAR. Corrected and uncorrected CT data were compared to synthetic CT data to evaluate accuracy of HU reproduction. Intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) plans were calculated in Oncentra v4.3 on corrected and uncorrected CT data and compared to Gafchromic™ EBT3 films to assess accuracy of dose calculation.RESULTS:
The use of iMAR increased the accuracy of HU reproduction. The average deviation of HU decreased from 1006 HU to 408 HU in areas including metal and from 283 HU to 33 HU in tissue areas excluding metal. Dose calculation accuracy could be significantly improved for all phantoms and plans The mean passing rate for gamma evaluation with 3 % dose tolerance and 3 mm distance to agreement increased from 90.6 % to 96.2 % if artifacts were corrected by iMAR.CONCLUSION:
The application of iMAR allows metal artifacts to be removed to a great extent which leads to a significant increase in dose calculation accuracy.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Radiometria
/
Planejamento da Radioterapia Assistida por Computador
/
Intensificação de Imagem Radiográfica
/
Tomografia Computadorizada por Raios X
/
Implantes Dentários
/
Artefatos
Tipo de estudo:
Diagnostic_studies
Limite:
Humans
Idioma:
En
Revista:
Strahlenther Onkol
Assunto da revista:
NEOPLASIAS
/
RADIOTERAPIA
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Alemanha