Abstract:
:Monte Carlo simulation with PENELOPE (version 2003) is applied to calculate Leksell Gamma Knife dose distributions for heterogeneous phantoms. The usual spherical water phantom is modified with a spherical bone shell simulating the skull and an air-filled cube simulating the frontal or maxillary sinuses. Different simulations of the 201 source configuration of the Gamma Knife have been carried out with a simplified model of the geometry of the source channel of the Gamma Knife recently tested for both single source and multisource configurations. The dose distributions determined for heterogeneous phantoms including the bone- and/or air-tissue interfaces show non-negligible differences with respect to those calculated for a homogeneous one, mainly when the Gamma Knife isocentre approaches the separation surfaces. Our findings confirm an important underdosage (approximately 10%) nearby the air-tissue interface, in accordance with previous results obtained with the PENELOPE code with a procedure different from ours. On the other hand, the presence of the spherical shell simulating the skull produces a few per cent underdosage at the isocentre wherever it is situated.
journal_name
Phys Med Bioljournal_title
Physics in medicine and biologyauthors
Al-Dweri FM,Rojas EL,Lallena AMdoi
10.1088/0031-9155/50/23/018subject
Has Abstractpub_date
2005-12-07 00:00:00pages
5665-78issue
23eissn
0031-9155issn
1361-6560pii
S0031-9155(05)02103-2journal_volume
50pub_type
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