On the equivalence of image-based dual-energy CT methods for the determination of electron density and effective atomic number in radiotherapy

Dual-energy computed tomography enables the determination of relative electron density and effective atomic number. As this can increase accuracy in radiotherapy treatment planning, a substantial number of algorithms for the determination of the two quantities has been suggested – most of them based...

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Bibliographic Details
Main Authors: Christian Möhler, Patrick Wohlfahrt, Christian Richter, Steffen Greilich
Format: Article
Language:English
Published: Elsevier 2018-01-01
Series:Physics and Imaging in Radiation Oncology
Online Access:http://www.sciencedirect.com/science/article/pii/S2405631617300611
Description
Summary:Dual-energy computed tomography enables the determination of relative electron density and effective atomic number. As this can increase accuracy in radiotherapy treatment planning, a substantial number of algorithms for the determination of the two quantities has been suggested – most of them based on reconstructed CT images. We show that many of these methods share a common theoretical framework. Equations can be transformed from one method to the other by re-definition of the calibration parameters. We suggest that further work should be spent on practical calibration and the reliability of CT numbers rather than on the theoretical framework. Keywords: Material characterization, Radiotherapy, Treatment planning, Dose calculation, Proton and ion beam therapy
ISSN:2405-6316