Dynamic splitting of Gaussian pencil beams in heterogeneity-correction algorithms for radiotherapy with heavy charged particles.
Phys Med Biol
; 54(7): 2015-27, 2009 Apr 07.
Article
en En
| MEDLINE
| ID: mdl-19287085
ABSTRACT
The pencil-beam algorithm is valid only when elementary Gaussian beams are small enough compared to the lateral heterogeneity of a medium, which is not always true in actual radiotherapy with protons and ions. This work addresses a solution for the problem. We found approximate self-similarity of Gaussian distributions, with which Gaussian beams can split into narrower and deflecting daughter beams when their sizes have overreached lateral heterogeneity in the beam-transport calculation. The effectiveness was assessed in a carbon-ion beam experiment in the presence of steep range compensation, where the splitting calculation reproduced a detour effect amounting to about 10% in dose or as large as the lateral particle disequilibrium effect. The efficiency was analyzed in calculations for carbon-ion and proton radiations with a heterogeneous phantom model, where the beam splitting increased computing times by factors of 4.7 and 3.2. The present method generally improves the accuracy of the pencil-beam algorithm without severe inefficiency. It will therefore be useful for treatment planning and potentially other demanding applications.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Radioterapia
/
Algoritmos
/
Radioterapia de Iones Pesados
Tipo de estudio:
Prognostic_studies
Idioma:
En
Año:
2009
Tipo del documento:
Article