Simulation and experimental verification of ambient neutron doses in a pencil beam scanning proton therapy room as a function of treatment plan parameters

Out-of-field patient doses in proton therapy are dominated by neutrons. Currently, they are not taken into account by treatment planning systems. There is an increasing need to include out-of-field doses in the dose calculation, especially when treating children, pregnant patients, and patients with...

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Detalles Bibliográficos
Autores: Van Hoey, Olivier, Stolarczyk, Liliana, Lillhök, Jan, Eliasson, Linda, Mojzeszek, Natalia, Liszka, Malgorzata, Alkhiat, Ali, Mares, Vladimir, Trompier, François, Trinkl, Sebastian, Martínez-Rovira, Immaculada|||0000-0002-2918-489X, Romero-Expósito, Maite, Domingo, Carles|||0000-0002-8480-692X, Ploc, Ondrej, Harrison, Roger, Olko, Pawel
Tipo de recurso: artículo
Fecha de publicación:2022
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:266406
Acceso en línea:https://ddd.uab.cat/record/266406
https://dx.doi.org/urn:doi:10.3389/fonc.2022.903537
Access Level:acceso abierto
Palabra clave:Proton therapy
Pencil beam scanned proton therapy
Neutron doses
Monte Carlo simulations
Out-of-field neutron doses in radiation therapy
Neutron measurements
Descripción
Sumario:Out-of-field patient doses in proton therapy are dominated by neutrons. Currently, they are not taken into account by treatment planning systems. There is an increasing need to include out-of-field doses in the dose calculation, especially when treating children, pregnant patients, and patients with implants. In response to this demand, this work presents the first steps towards a tool for the prediction of out-of-field neutron doses in pencil beam scanning proton therapy facilities. As a first step, a general Monte Carlo radiation transport model for simulation of out-of-field neutron doses was set up and successfully verified by comparison of simulated and measured ambient neutron dose equivalent and neutron fluence energy spectra around a solid water phantom irradiated with a variation of different treatment plan parameters. Simulations with the verified model enabled a detailed study of the variation of the neutron ambient dose equivalent with field size, range, modulation width, use of a range shifter, and position inside the treatment room. For future work, it is planned to use this verified model to simulate out-of-field neutron doses inside the phantom and to verify the simulation results by comparison with previous in-phantom measurement campaigns. Eventually, these verified simulations will be used to build a library and a corresponding tool to allow assessment of out-of-field neutron doses at pencil beam scanning proton therapy facilities.