Abstract:
:Voxelized geometry such as those obtained from medical images is increasingly used in Monte Carlo calculations of absorbed doses. One useful application of calculated absorbed dose is the determination of fluence-to-dose conversion factors for different organs. However, confusion still exists about how such a geometry is defined and how the energy deposition is best computed, especially involving a popular code, MCNP5. This study investigated two different types of geometries in the MCNP5 code, cell and lattice definitions. A 10 cm x 10 cm x 10 cm test phantom, which contained an embedded 2 cm x 2 cm x 2 cm target at its center, was considered. A planar source emitting parallel photons was also considered in the study. The results revealed that MCNP5 does not calculate total target volume for multi-voxel geometries. Therefore, tallies which involve total target volume must be divided by the user by the total number of voxels to obtain a correct dose result. Also, using planar source areas greater than the phantom size results in the same fluence-to-dose conversion factor.
journal_name
Health Physjournal_title
Health physicsauthors
Zhang J,Bednarz B,Xu XGdoi
10.1097/01.HP.0000234039.58356.desubject
Has Abstractpub_date
2006-11-01 00:00:00pages
S59-65issue
5 Suppleissn
0017-9078issn
1538-5159pii
00004032-200611002-00005journal_volume
91pub_type
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