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A CT‐based Monte Carlo simulation tool for dosimetry planning and analysis
Author(s) -
DeMarco J. J.,
Solberg T. D.,
Smathers J. B.
Publication year - 1998
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.598167
Subject(s) - imaging phantom , monte carlo method , dosimetry , voxel , radiation treatment planning , computer science , computational physics , computational science , nuclear medicine , simulation , medical physics , physics , optics , mathematics , statistics , radiation therapy , artificial intelligence , radiology , medicine
The Los Alamos code MCNP4A (M_onte C_arlo N_‐P_article version 4A) is currently used to simulate a variety of problems ranging from nuclear reactor analysis to boron neutron capture therapy. A graphical user interface has been developed that automatically sets up the MCNP4A geometry and radiation source requirements for a three‐dimensional Monte Carlo simulation using computed tomography data. The major drawback for this dosimetry system is the amount of time to obtain a statistically significant answer. A specialized patch file has been developed that optimizes photon particle transport and dose scoring within the standard MCNP4A lattice geometry. The transport modifications produce a performance increase (number of histories per minute) of approximately 4.7 based upon a 6 MV point source centered within a 30 × 30 × 30 cm 3lattice water phantom and 1 × 1 × 1 mm 3voxels. The dose scoring modifications produce a performance increase of approximately 470 based upon a tally section of greater than1 × 10 4lattice elements and a voxel size of 5 mm 3 . Homogeneous and heterogeneous benchmark calculations produce good agreement with measurements using a standard water phantom and a high‐ and low‐density heterogeneity phantom. The dose distribution from a typical mediastinum treatment planning setup is presented for qualitative analysis and comparison versus a conventional treatment planning system.