A comparison of patient position displacements from body surface laser scanning and cone beam CT bone registrations for radiotherapy of pelvic targets.
Acta Oncol
; 53(2): 268-77, 2014 Feb.
Article
em En
| MEDLINE
| ID: mdl-23786175
ABSTRACT
BACKGROUND AND PURPOSE:
Optical surface detection has attractive features as a mean in radiotherapy for patient positioning tasks such as set-up, monitoring and gating. To aid in hitting radiotherapy targets the correlation between detected surface displacements and internal structure displacements is crucial. In this study, we compare set-up displacements derived from a body surface laser scanning (BSLS) system to displacements derived from bone registrations with a cone beam computed tomography (CBCT) system in order to quantify the accuracy and applicability of BSLS for fractionated treatments in the pelvic region. MATERIAL ANDMETHODS:
Displacements from concurrent BSLS and CBCT registrations were compared for 40 patients treated in the pelvic region for a total of 170 set-ups. Surface data captured by BSLS at the first treatment fraction (BSLSref) was used as main reference for the BSLS system, while bony structures from the planning CT were used as a reference for the CBCT method. As comparison, the patient outline extracted from the planning CT was used as BSLS reference (CTref). The displacements detected by the CBCT system (skin-marks-only) was also used for comparison.RESULTS:
The mean differences (± 1 SD) between the BSLS and CBCT displacements were -0.01 (± 0.17) cm, 0.00 (± 0.21) cm and 0.01 (± 0.17) cm in the lateral, longitudinal and vertical directions, respectively. The median length of the difference was 0.26 cm (0.24-0.29 cm, 95% CI). The median of the difference between CBCT and BSLS displacements based on CTref was 0.37 cm (0.30-0.39 cm) and the median for skin-marks-only was 0.38 cm (0.34-0.42 cm).CONCLUSIONS:
The BSLS system is a good supplement to the CBCT system for accurate set-up for fractions when no CBCT is deemed necessary for pelvic targets. Inter-fractional skin movement in relation to bone was estimated to be 0.2 cm in the lateral (X), longitudinal (Y) and vertical direction (Z), respectively.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Pelve
/
Planejamento da Radioterapia Assistida por Computador
/
Interpretação de Imagem Assistida por Computador
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Tomografia Computadorizada de Feixe Cônico
/
Imagem Óptica
Limite:
Female
/
Humans
/
Male
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article