Image quality and dose evaluation of MVCT TomoTherapy acquisitions: A phantom study.
Image guided radiotherapy
Image quality
Megavoltage computed tomography
Pre-treatment imaging
Tomotherapy
Journal
Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB)
ISSN: 1724-191X
Titre abrégé: Phys Med
Pays: Italy
ID NLM: 9302888
Informations de publication
Date de publication:
Jan 2019
Jan 2019
Historique:
received:
29
10
2018
revised:
22
12
2018
accepted:
08
01
2019
entrez:
11
2
2019
pubmed:
11
2
2019
medline:
15
3
2019
Statut:
ppublish
Résumé
The aim of this study is to evaluate the dose delivered and the image quality of pre-treatment MVCT images with Hi-Art TomoTherapy system, varying acquisition and reconstruction parameters. Catphan 500 MVCT images were acquired with all acquisition pitch and reconstruction intervals; image quality was evaluated in terms of noise, uniformity, contrast linearity, contrast-to-noise ratio (CNR) and spatial resolution with the Modulation Transfer Function (MTF). Dose was evaluated as Multi Slice Average Dose (MSAD Differences in noise and uniformity, though statistically significant in some cases, were very small: noise ranged from 2.3% for Coarse - 3 mm to 2.4% for Coarse - 6 mm, while uniformity passed from 99.5% for Coarse - 6 mm to 99.8% for Normal - 4 mm. No differences at all were found for CNR for high and low density inserts, while MTF was higher for pitch Coarse, even if no differences in spatial resolution were observed visually (spatial resolution was up to 4 lp/cm for all combinations of pitch and reconstruction interval). Dose was dependent on pitch, being 1.0 cGy for Coarse, 1.5 cGy for Normal and 2.85 cGy for Fine. We observed negligible differences in image quality among different pitch and reconstruction interval, thus, considerations regarding pre-treatment imaging modalities should be based only on dose delivered and on the desired resolution along the cranio-caudal axis for image-guided radiotherapy and adaptive radiotherapy purposes.
Sections du résumé
BACKGROUND
BACKGROUND
The aim of this study is to evaluate the dose delivered and the image quality of pre-treatment MVCT images with Hi-Art TomoTherapy system, varying acquisition and reconstruction parameters.
MATERIALS AND METHODS
METHODS
Catphan 500 MVCT images were acquired with all acquisition pitch and reconstruction intervals; image quality was evaluated in terms of noise, uniformity, contrast linearity, contrast-to-noise ratio (CNR) and spatial resolution with the Modulation Transfer Function (MTF). Dose was evaluated as Multi Slice Average Dose (MSAD
RESULTS
RESULTS
Differences in noise and uniformity, though statistically significant in some cases, were very small: noise ranged from 2.3% for Coarse - 3 mm to 2.4% for Coarse - 6 mm, while uniformity passed from 99.5% for Coarse - 6 mm to 99.8% for Normal - 4 mm. No differences at all were found for CNR for high and low density inserts, while MTF was higher for pitch Coarse, even if no differences in spatial resolution were observed visually (spatial resolution was up to 4 lp/cm for all combinations of pitch and reconstruction interval). Dose was dependent on pitch, being 1.0 cGy for Coarse, 1.5 cGy for Normal and 2.85 cGy for Fine.
CONCLUSIONS
CONCLUSIONS
We observed negligible differences in image quality among different pitch and reconstruction interval, thus, considerations regarding pre-treatment imaging modalities should be based only on dose delivered and on the desired resolution along the cranio-caudal axis for image-guided radiotherapy and adaptive radiotherapy purposes.
Identifiants
pubmed: 30738526
pii: S1120-1797(19)30009-2
doi: 10.1016/j.ejmp.2019.01.009
pii:
doi:
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
200-206Informations de copyright
Copyright © 2019 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.