Inter-comparison of phantoms for CT numbers to relative electron density (RED)/physical density calibration and influence to dose calculation in TPS
Result description
Calibration curves from CT numbers to electron/physical densities in treatment planning systems (TPS) is an important part of commissioning. The aim of this work was to compare phantoms manufactured by different vendors. 6 phantoms were included in the study (2x CIRS, 1x Agmeco, 1x QUASAR, 1x Gammex, 1x CatPhan) to evaluate the sensitivity of dose calculated by TPS to calibration curve. All phantoms were scanned at two centres with 2 CT scanners under different protocols with various kV. The influence of different calibration curves on dose calculation in the TPS has been estimated. The presence of titanium and the scattering material has been evaluated. The sensitivity of RED to dose is higher for CT numbers higher than 100 HU (10% change in RED caused 3% and 1,5% in dose for 6MV and 18 MV respectively for material of 10 cm thickness). The largest sensitivity was observed for dense bone (up to 3,5% in dose for 6MV). The CT spectra can influence doses up to 4,5% and 2,5% for 6MV and 18 MV respectively. Two phantoms by the same vendor differed for dense bone up to 2% and 1% in dose for 6MV and 18 MV respectively. Phantoms used for CT-RED calibration were compared and various conditions and their influence to dose calculated by TPS was evaluated.
Keywords
CT numberElectron densityPhantomsInhomogeneitiesRadiotherapy
The result's identifiers
Result code in IS VaVaI
Alternative codes found
RIV/00064203:_____/19:10395254
Result on the web
https://iopscience.iop.org/article/10.1088/1742-6596/1248/1/012046/pdf
DOI - Digital Object Identifier
Alternative languages
Result language
angličtina
Original language name
Inter-comparison of phantoms for CT numbers to relative electron density (RED)/physical density calibration and influence to dose calculation in TPS
Original language description
Calibration curves from CT numbers to electron/physical densities in treatment planning systems (TPS) is an important part of commissioning. The aim of this work was to compare phantoms manufactured by different vendors. 6 phantoms were included in the study (2x CIRS, 1x Agmeco, 1x QUASAR, 1x Gammex, 1x CatPhan) to evaluate the sensitivity of dose calculated by TPS to calibration curve. All phantoms were scanned at two centres with 2 CT scanners under different protocols with various kV. The influence of different calibration curves on dose calculation in the TPS has been estimated. The presence of titanium and the scattering material has been evaluated. The sensitivity of RED to dose is higher for CT numbers higher than 100 HU (10% change in RED caused 3% and 1,5% in dose for 6MV and 18 MV respectively for material of 10 cm thickness). The largest sensitivity was observed for dense bone (up to 3,5% in dose for 6MV). The CT spectra can influence doses up to 4,5% and 2,5% for 6MV and 18 MV respectively. Two phantoms by the same vendor differed for dense bone up to 2% and 1% in dose for 6MV and 18 MV respectively. Phantoms used for CT-RED calibration were compared and various conditions and their influence to dose calculated by TPS was evaluated.
Czech name
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Czech description
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Classification
Type
D - Article in proceedings
CEP classification
—
OECD FORD branch
20601 - Medical engineering
Result continuities
Project
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2019
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Article name in the collection
Journal of Physics Conference Series, 18th Asia-Oceania Congress of Medical Physics (AOCMP) / 16th South-East Asia Congress of Medical Physics (SEACOMP)
ISBN
—
ISSN
1742-6588
e-ISSN
1742-6596
Number of pages
6
Pages from-to
1-6
Publisher name
IOP PUBLISHING
Place of publication
Bristol
Event location
Kuala Lumpur, MALAYSIA
Event date
Nov 11, 2018
Type of event by nationality
WRD - Celosvětová akce
UT code for WoS article
000492968100046
Basic information
Result type
D - Article in proceedings
OECD FORD
Medical engineering
Year of implementation
2019