Dosimetric impact of dual-energy CT tissue segmentation for low-energy prostate brachytherapy: a Monte Carlo study.

Dosimetric impact of dual-energy CT tissue segmentation for low-energy prostate brachytherapy: a Monte Carlo study.
Phys Med Biol. 2017 Dec 20;:
Authors: Remy C, Lalonde A, Béliveau-Nadeau D, Carrier JF, Bouchard H
Abstract
{\color{red}The purpose of this study is} to evaluate the impact of a novel tissue characterization method using dual-energy over single-energy computed tomography (DECT and SECT) on Monte Carlo (MC) dose calculations for low-dose rate (LDR) prostate brachytherapy performed in a patient like geometry.
 A virtual patient geometry is created using contours from a real patient pelvis CT scan, where known elemental compositions and varying densities are overwritten in each voxel. A second phantom is made with additional calcifications. \textcolor{red}{Both phantoms are the ground truth with which all results are compared.} Simulated CT images are generated \textcolor{red}{from them} using attenuation coefficients taken from the XCOM database with a 100 kVp spectrum for SECT and 80 and 140Sn kVp for DECT. Tissue segmentation for Monte Carlo dose calculation is made using a stoichiometric calibration method for the simulated SECT images. For the DECT images, Bayesian eigentissue decomposition is used. A LDR prostate brachytherapy plan is defined with $ ^{125}$I sources and then calculated using the EGSnrc user-code Brachydose for each case. Dose distributions and dose-volume histograms (DVH) are compared to gro...

Source: Physics in Medicine and Biology - December 20, 2017 Category: Physics Authors: Remy C, Lalonde A, Béliveau-Nadeau D, Carrier JF, Bouchard H Tags: Phys Med Biol Source Type: research