@article{096c82dcef5b46f4a7597c7b65725a2b,
title = "Technical Note: Relative proton stopping power estimation from virtual monoenergetic images reconstructed from dual-layer computed tomography",
abstract = "PurposeThe objective of this technical note was to investigate the accuracy of proton stopping power relative to water (RSP) estimation using a novel dual-layer, dual-energy computed tomography (DL-DECT) scanner for potential use in proton therapy planning. DL-DECT allows dual-energy reconstruction from scans acquired at a single x-ray tube voltage V by using two-layered detectors.MethodsSets of calibration and evaluation inserts were scanned at a DL-DECT scanner in a custom phantom with variable diameter D (0 to 150mm) at V of 120 and 140kV. Inserts were additionally scanned at a synchrotron computed tomography facility to obtain comparative linear attenuation coefficients for energies from 50 to 100keV, and reference RSP was obtained using a carbon ion beam and variable water column. DL-DECT monoenergetic (mono-E) reconstructions were employed to obtain RSP by adapting the Yang-Saito-Landry (YSL) method. The method was compared to reference RSP via the root mean square error (RMSE) over insert mean values obtained from volumetric regions of interest. The accuracy of intermediate quantities such as the relative electron density (RED), effective atomic number (EAN), and the mono-E was additionally evaluated.ResultsThe lung inserts showed higher errors for all quantities and we report RMSE excluding them. RMSE for from DL-DECT mono-E was below 1.9%. For the evaluation inserts at D=150mm and V=140kV, RED RMSE was 1.0%, while for EAN it was 2.9%. RSP RMSE was below 0.8% for all D and V, which did not strongly affect the results.ConclusionsIn this investigation of RSP accuracy from DL-DECT, we have shown that RMSE below 1% can be achieved. It was possible to adapt the YSL method for DL-DECT and intermediate quantities RED and EAN had comparable accuracy to previous publications.",
keywords = "dual-energy CT, dual-layer CT, monoenergetic imaging, proton therapy, relative stopping power, synchrotron CT, ENERGY CT, ELECTRON-DENSITY, SINGLE, RATIO, ATTENUATION, PREDICTION, NUMBERS, BEAM, HEAD",
author = "Guillaume Landry and Fabian Doerringer and Salim Si-Mohamed and Philippe Douek and Abascal, {Juan F. P. J.} and Francoise Peyrin and Almeida, {Isabel P.} and Frank Verhaegen and Ilaria Rinaldi and Katia Parodi and Simon Rit",
note = "Funding Information: The authors thank the Heidelberg Ion-Beam Therapy Center (HIT) for allocated beam time, and we are grateful to Stefan Brons for local experimental support and Gloria Vilches-Freixas for assistance in measuring the reference water equivalent thickness values of the phantom inserts. The authors also thank the European Synchrotron Radiation Facility for allocated beam time within the experiment MD1045 at the beamline ID17, and we are grateful to Alberto Bravin, Claude Goubet, Tom Hohweiller, Cyril Mory, C{\'e}cile Olivier, Odran Pivot, and Herwig Requardt for assistance in acquiring synchrotron CT images. This work was supported by the German Research Foundation's (DFG) Cluster of Excellence Munich-Centre for Advanced Photonics (MAP) and by the Bavaria-France Cooperation Centre (BFHZ). JFPJ Abascal has received funding from the European Union's Horizon 2020 Research and Innovation programme under the Marie Sklodowska-Curie grant agreement No. 701915. This work was performed within the framework of the LABEX PRIMES (ANR-11-LABX-0063) of Universit{\'e} de Lyon, within the program “Investissements d'Avenir” (ANR-11-IDEX-0007) operated by the French National Research Agency (ANR). Funding Information: The authors thank the Heidelberg Ion-Beam Therapy Center (HIT) for allocated beam time, and we are grateful to Stefan Brons for local experimental support and Gloria Vilches-Freixas for assistance in measuring the reference water equivalent thickness values of the phantom inserts. The authors also thank the European Synchrotron Radiation Facility for allocated beam time within the experiment MD1045 at the beamline ID17, and we are grateful to Alberto Bravin, Claude Goubet, Tom Hohweiller, Cyril Mory, C{\'e}cile Olivier, Odran Pivot, and Herwig Requardt for assistance in acquiring synchrotron CT images. This work was supported by the German Research Foundation{\textquoteright}s (DFG) Cluster of Excellence Munich-Centre for Advanced Photonics (MAP) and by the Bavaria-France Cooperation Centre (BFHZ). JFPJ Abascal has received funding from the European Union{\textquoteright}s Horizon 2020 Research and Innovation programme under the Marie Sklodowska-Curie grant agreement No. 701915. This work was performed within the framework of the LABEX PRIMES (ANR-11-LABX-0063) of Universit{\'e}de Lyon, within the program “Investissements d{\textquoteright}Avenir” (ANR-11-IDEX-0007) operated by the French National Research Agency (ANR). Publisher Copyright: {\textcopyright} 2019 American Association of Physicists in Medicine",
year = "2019",
month = apr,
doi = "10.1002/mp.13404",
language = "English",
volume = "46",
pages = "1821--1828",
journal = "Medical Physics",
issn = "0094-2405",
publisher = "John Wiley & Sons Inc.",
number = "4",
}