Effects of bone- and air-tissue inhomogeneities on the dose distributions of the Leksell Gamma Knife® calculated with PENELOPE
Feras M O Al-Dweri, E Leticia Rojas, Antonio M Lallena
2005
Physics in Medicine and Biology
Monte Carlo simulation with PENELOPE (v. 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
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... th 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 isocenter approaches the separation surfaces. Our findings confirm an important underdosage (∼10 interface, in accordance with previous results obtained with PENELOPE code with a procedure different to ours. On the other hand, the presence of the spherical shell simulating the skull produces a few percent underdosage at the isocenter wherever it is situated.
doi:10.1088/0031-9155/50/23/018
pmid:16306660
fatcat:wtbyfjizavaxxptidhpweqhl7e