A kernel-based algorithm for the spectral fluence of clinical proton beams to calculate dose-averaged LET and other dosimetric quantities of interest.
LETd
analytical calculation
proton fluence algorithm
proton therapy
Journal
Medical physics
ISSN: 2473-4209
Titre abrégé: Med Phys
Pays: United States
ID NLM: 0425746
Informations de publication
Date de publication:
Jun 2020
Jun 2020
Historique:
received:
02
08
2019
revised:
11
11
2019
accepted:
29
11
2019
pubmed:
4
3
2020
medline:
15
5
2021
entrez:
4
3
2020
Statut:
ppublish
Résumé
To introduce a new analytical methodology to calculate quantities of interest in particle radiotherapy inside the treatment planning system. Models are proposed to calculate dose-averaged LET (LETd) in proton radiotherapy. A kernel-based approach for the spectral fluence of particles is developed by means of analytical functions depending on depth and lateral position. These functions are obtained by fitting them to data calculated with Monte Carlo (MC) simulations using Geant4 in liquid water for energies from 50 to 250 MeV. Contributions of primary, secondary protons and alpha particles are modeled separately. Lateral profiles and spectra are modeled as Gaussian functions to be convolved with the fluence coming from the nozzle. LETd is obtained by integrating the stopping power curves from the PSTAR and ASTAR databases weighted by the spectrum at each position. The fast MC code MCsquare is employed to benchmark the results. Considering the nine energies simulated, fits for the functions modeling the fluence in-depth provide an average This new spectral fluence-based methodology allows for simultaneous calculations of quantities of interest in proton radiotherapy such as dose, LETd or microdosimetric quantities. The method also enables the inclusion of more particles by following an analogous process.
Substances chimiques
Protons
0
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
2495-2505Subventions
Organisme : Spanish Ministry of Economy and Competitiveness
ID : FPA2016-77689-C2-1-R
Informations de copyright
© 2020 American Association of Physicists in Medicine.
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