Study of the effect of ceramic Ta2O5nanoparticle distribution on cellular dose enhancement in a kilovoltage photon field.
The application of nanoparticles (NPs) in radiotherapy is an increasingly attractive technique to improve clinical outcomes. The internalisation of NPs within the tumour cells enables an increased radiation dose to critical cellular structures. The purpose of this study is to investigate, by means of Geant4 simulations, the dose enhancement within a cell population irradiated with a 150kVp photon field in the presence of a varying concentration of tantalum pentoxide (Ta2O5) NP aggregates, experimentally observed to form shells within tumour cells. This scenario is compared to the more traditionally simulated homogeneous solution of NP material in water with the same weight fraction of Ta2O5, as well as to a cell population without NPs present. The production of secondary electrons is enhanced by increased photoelectric effect interactions within the high-Z material and this is examined in terms of their kinetic energy spectra and linear energy transfer (LET) with various NP distributions compared to water. Our results indicate that the shell formation scenario limits the dose enhancement at 150kVp. The underlying mechanism for this limit is discussed.
Centre for Medical Radiation Physics (CMRP), University of Wollongong, NSW, Australia.
Sally
S
McKinnon
Centre for Medical Radiation Physics (CMRP), University of Wollongong, NSW, Australia.
Elette
E
Engels
Centre for Medical Radiation Physics (CMRP), University of Wollongong, NSW, Australia; Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, NSW, Australia; Centre for Medical and Molecular Bioscience, University of Wollongong, NSW, Australia.
Moeava
M
Tehei
Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, NSW, Australia; Institute for Superconducting and Electronic Materials, University of Wollongong, NSW, Australia.
Konstantin
K
Konstantinov
Centre for Medical Radiation Physics (CMRP), University of Wollongong, NSW, Australia; Radiation Oncology Department, Prince of Wales Hospital, Randwick, NSW, Australia.
Stéphanie
S
Corde
Centre for Medical Radiation Physics (CMRP), University of Wollongong, NSW, Australia; Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, NSW, Australia; Centre for Medical and Molecular Bioscience, University of Wollongong, NSW, Australia.
Sianne
S
Oktaria
CNRS/IN2P3, Centre d'Etudes Nucléaires de Bordeaux-Gradignan, UMR-5797, chemin du solarium, 33175 Gradignan, France; Université Bordeaux, Centre d'Etudes Nucléaires de Bordeaux-Gradignan, UMR-5797, chemin du solarium, 33175 Gradignan, France.
Sebastien
S
Incerti
Centre for Medical Radiation Physics (CMRP), University of Wollongong, NSW, Australia; Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, NSW, Australia.
Michael
M
Lerch
Centre for Medical Radiation Physics (CMRP), University of Wollongong, NSW, Australia; Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, NSW, Australia.
Anatoly
A
Rosenfeld
Centre for Medical Radiation Physics (CMRP), University of Wollongong, NSW, Australia; Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, NSW, Australia. Electronic address: susanna@uow.edu.au.
Susanna
S
Guatelli
D000818:Animals; D055592:Biophysical Phenomena; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000528:radiation effects; D002516:Ceramics; D003198:Computer Simulation; D006801:Humans; D018499:Linear Energy Transfer; D053768:Metal Nanoparticles / Q000737:chemistry / Q000528:radiation effects* / Q000627:therapeutic use*; D008954:Models, Biological; D009010:Monte Carlo Method; D009369:Neoplasms / Q000532:radiotherapy; D010087:Oxides; D017785:Photons / Q000627:therapeutic use; D011879:Radiotherapy Dosage; D051381:Rats; D013635:Tantalum
D010087:Oxides; D013635:Tantalum; C078151:tantalum oxide
Ceramic nanoparticles; Dose enhancement; Geant4; Monte Carlo method; X-ray radiotherapy