Monte Carlo calculated CT numbers for improved heavy ion treatment planning

• Authors: Sima Qamhiyeh , Anna Wysocka-Rabin , Oliver Jäkel
• Languages of publication: EN

Abstracts

EN

Better knowledge of CT number values and their uncertainties can be applied to improve heavy ion treatment planning. We developed a novel method to calculate CT numbers for a computed tomography (CT) scanner using the Monte Carlo (MC) code, BEAMnrc/EGSnrc. To generate the initial beam shape and spectra we conducted full simulations of an X-ray tube, filters and beam shapers for a Siemens Emotion CT. The simulation output files were analyzed to calculate projections of a phantom with inserts. A simple reconstruction algorithm (FBP using a Ram-Lak filter) was applied to calculate the pixel values, which represent an attenuation coefficient, normalized in such a way to give zero for water (Hounsfield unit (HU)). Measured and Monte Carlo calculated CT numbers were compared. The average deviation between measured and simulated CT numbers was 4 ± 4 HU and the standard deviation σ was 49 ± 4 HU. The simulation also correctly predicted the behaviour of H-materials compared to a Gammex tissue substitutes. We believe the developed approach represents a useful new tool for evaluating the effect of CT scanner and phantom parameters on CT number values.

Keywords

EN

X-ray tomography; Monte Carlo (MC) method; treatment planning; hadrontherapy

• Publisher: De Gruyter Open
• Journal: Nukleonika
• Year: 2014
• Volume: 59
• Issue: 1
• Pages: 15-23

Dates

published

1 - 03 - 2014

online

25 - 03 - 2014

Contributors

author

Sima Qamhiyeh

• West German Proton Therapy Centre Essen (WPE), Hufelandstraße 55, 45147 Essen, Germany

author

Anna Wysocka-Rabin

• Division of Accelerator Physics, National Centre for Nuclear Research (NCBJ), 7 Andrzeja Soltana Str., 05-400 Otwock/Świerk, Poland, Tel.: [phone], Fax: [phone]

author

Oliver Jäkel

• Heidelberg Ion-Beam Therapy Centre HIT, Im Neuenheimer Feld 450, 69120 Heidelberg, Germany

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Identifiers

DOI

10.2478/nuka-2014-0002