1. Technical Note
- Author
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Frank Verhaegen, Salim Si-Mohamed, Ilaria Rinaldi, Juan F. P. J. Abascal, Isabel P. Almeida, Françoise Peyrin, Guillaume Landry, Katia Parodi, Simon Rit, Fabian Dörringer, Philippe Douek, Department of Medical Physics, Ludwig-Maximilians-Universität München (LMU), Service de Radiologie et IRM [CHU Lyon], Hospices Civils de Lyon (HCL), Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales (MOTIVATE), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Imagerie Tomographique et Radiothérapie, European Synchrotron Radiation Facility (ESRF), Maastricht Radiation Oncology Clinic (MAASTRO), Maastricht University [Maastricht], Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), RS: GROW - R3 - Innovative Cancer Diagnostics & Therapy, Promovendi ODB, and Radiotherapie
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Organs at Risk ,[SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging ,PREDICTION ,relative stopping power ,BEAM ,dual-energy CT ,030218 nuclear medicine & medical imaging ,0302 clinical medicine ,ATTENUATION ,dual layer CT ,[INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing ,Neoplasms ,Image Processing, Computer-Assisted ,proton therapy ,Lung ,ComputingMilieux_MISCELLANEOUS ,Physics ,NUMBERS ,Phantoms, Imaging ,Detector ,Radiotherapy Dosage ,General Medicine ,ENERGY CT ,synchrotron CT ,SINGLE ,030220 oncology & carcinogenesis ,Calibration ,[PHYS.PHYS.PHYS-MED-PH]Physics [physics]/Physics [physics]/Medical Physics [physics.med-ph] ,Scanner ,Mean squared error ,Electrons ,Imaging phantom ,03 medical and health sciences ,Optics ,RATIO ,Humans ,HEAD ,Proton therapy ,mono‐energetic imaging ,business.industry ,Radiotherapy Planning, Computer-Assisted ,Attenuation ,Water ,dual-layer CT ,monoenergetic imaging ,Radiotherapy, Intensity-Modulated ,Tomography, X-Ray Computed ,business ,Synchrotrons ,Effective atomic number ,ELECTRON-DENSITY ,dual energy CT - 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.
- Published
- 2019