Monte Carlo dose mapping on deforming anatomy. Phys Med Biol 2009 Oct 07;54(19):5815-30
Date
09/11/2009Pubmed ID
19741278Pubmed Central ID
PMC2849146DOI
10.1088/0031-9155/54/19/010Scopus ID
2-s2.0-70350623229 (requires institutional sign-in at Scopus site) 48 CitationsAbstract
This paper proposes a Monte Carlo-based energy and mass congruent mapping (EMCM) method to calculate the dose on deforming anatomy. Different from dose interpolation methods, EMCM separately maps each voxel's deposited energy and mass from a source image to a reference image with a displacement vector field (DVF) generated by deformable image registration (DIR). EMCM was compared with other dose mapping methods: energy-based dose interpolation (EBDI) and trilinear dose interpolation (TDI). These methods were implemented in EGSnrc/DOSXYZnrc, validated using a numerical deformable phantom and compared for clinical CT images. On the numerical phantom with an analytically invertible deformation map, EMCM mapped the dose exactly the same as its analytic solution, while EBDI and TDI had average dose errors of 2.5% and 6.0%. For a lung patient's IMRT treatment plan, EBDI and TDI differed from EMCM by 1.96% and 7.3% in the lung patient's entire dose region, respectively. As a 4D Monte Carlo dose calculation technique, EMCM is accurate and its speed is comparable to 3D Monte Carlo simulation. This method may serve as a valuable tool for accurate dose accumulation as well as for 4D dosimetry QA.
Author List
Zhong H, Siebers JVAuthor
Hualiang Zhong PhD Associate Professor in the Radiation Oncology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
HumansLung
Monte Carlo Method
Phantoms, Imaging
Radiometry
Reproducibility of Results
Tomography, X-Ray Computed