Assessment of a radiotherapy patient cranial immobilization device using daily on-board kilovoltage imaging.
Vet Radiol Ultrasound
; 50(2): 230-4, 2009.
Article
em En
| MEDLINE
| ID: mdl-19400474
ABSTRACT
The purpose of this study was to utilize state-of-the-art on-board digital kilovoltage (kV) imaging to determine the systematic and random set-up errors of an immobilization device designed for canine and feline cranial radiotherapy treatments. The immobilization device is comprised of a custom made support bridge, bite block, vacuum-based foam mold and a modified thermoplastic mask attached to a commercially available head rest designed for human radiotherapy treatments. The immobilization device was indexed to a Varian exact couch-top designed for image guided radiation therapy (IGRT). Daily orthogonal kV images were compared to Eclipse treatment planning digitally reconstructed radiographs (DRRs). The orthogonal kV images and DRRs were directly compared online utilizing the Varian on-board imaging (OBI) system with set-up corrections mmediately and remotely transferred to the treatment couch prior to treatment delivery. Off-line review of 124 patient treatments indicates systematic errors consisting of +0.18 mm vertical, +0.39mm longitudinal and -0.08 mm lateral. The random errors corresponding to 2 standard deviations (95% CI) consist of 4.02 mm vertical, 2.97 mm longitudinal and 2.53 mm lateral and represent conservative CTV to PTV margins if kV OBI is not available. Use of daily kV OBI along with the cranial immobilization device permits reduction of the CTV to PTV margins to approximately 2.0 mm.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Doenças do Gato
/
Doenças do Cão
/
Radioterapia de Intensidade Modulada
/
Imobilização
/
Neoplasias
Tipo de estudo:
Diagnostic_studies
Limite:
Animals
Idioma:
En
Revista:
Vet Radiol Ultrasound
Assunto da revista:
DIAGNOSTICO POR IMAGEM
/
MEDICINA VETERINARIA
/
RADIOLOGIA
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Estados Unidos