The determination of a dose deposited in reference medium due to (p,n) reaction occurring during proton therapy

Dawidowska, Anna; Paluch-Ferszt, Monika; Konefał, Adam

doi:10.1016/j.rpor.2014.02.003

Cited by 8 publications

(5 citation statements)

References 14 publications

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“…Several studies have indicated that these reactions contribute to the total dose, as they produce secondary particles, in particular neutrons and γ-rays (see for example Ref. 9,10 ). Emission of multiple α-particles in proton-induced reaction on 16 O have also been reported, with a cross section of the order of 100 mb 7, 11 , i.e.…”

Section: Estimate Of the P+ 11 B→3α Dose Contributionmentioning

confidence: 99%

“…Neutron production in proton therapy has been extensively studied by means of MC simulations (see for example Ref. 9,10 ), indicating that their contribution to the total dose, together with the one of γ-rays, is not negligible. It may therefore be reasonable to believe that, in the presence of 10 B in the tissues, they produce an enhancement of the dose to the tissues, with high-LET α-particles, as envisaged in BNCT.…”

Section: Geant4 Simulationsmentioning

confidence: 99%

“…In any case, simulations confirm that the number of proton-or neutron-induced reactions on boron in proton therapy is practically negligible. An interesting behavior is observed when pure 10 B is loaded in the tissue. In this case, the number of α particles produced in the first two positions even decreases, relative to the pure water case.…”

Section: # Of α-Particlesmentioning

confidence: 99%

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On the (un)effectiveness of proton boron capture in proton therapy

et al. 2019

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We present calculations and simulations on the role of the p+ 11 B→3α reaction in proton therapy. This reaction has been recently suggested to be responsible for a decrease in the survival probability of tumor cells, when they are irradiated with low-energy protons. However, at the concentration levels typical of the proposed boron carrier (sodium borocaptate, Na 2 B 12 H 11 SH, in short BSH), i.e. less than 100 ppm, both calculations and Monte Carlo simulations suggest that the dose related to this reaction is orders of magnitude lower than the dose delivered by the primary proton beam inside the tissues. These calculations cast some doubts on the claim of an important role played by Proton Boron Capture in enhancing the therapeutic effectiveness of proton therapy, and suggest that other mechanisms should be investigated in order to explain the observed decrease in the survival probability.

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Section: Estimate Of the P+ 11 B→3α Dose Contributionmentioning

confidence: 99%

Section: Geant4 Simulationsmentioning

confidence: 99%

Section: # Of α-Particlesmentioning

confidence: 99%

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On the (un)effectiveness of proton boron capture in proton therapy

et al. 2019

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“…Specifically, the equivalent dose increased by factors of up to 1.86 and 384.68 with neutrons and gamma rays, respectively. Dawidowska et al ( 38 ) reported production of 0.1%, 0.4%, 0.5%, 0.6%, and 0.7% of neutrons from protons with energies of 50, 55, 60, 65, and 70 MeV, suggesting that higher incident energy in the protons increases neutron production. Based on this result, the production of secondary particles will increase further before the protons reach the tumor tissue inside the simulated body.…”

Section: Discussionmentioning

confidence: 99%

Secondary particle production and physical properties during dose enhancement for spread-out Bragg peaks

ChulHwan¹

2019

Transl. Cancer Res.

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Background The proton therapy is a form of particle radiation therapy that dose enhancement to improve therapeutic ratio (TR) is obtained by high-Z materials. This study evaluated the physical properties of dose enhancement and the resulting changes in the secondary particle production using the spread-out Bragg peak (SOBP). Methods Monte Carlo simulations were performed using the Geant4 software and the medical internal radiation dose head phantom. Gold and gadolinium were applied as enhancement materials at concentrations of 10, 20, and 30 mg/g in the tumor volume, and the composition of soft tissue was varied in parallel. The ratio of changes in the reaction caused by the interaction of the initial particles with the enhancement materials was calculated. Results Among the physical interaction processes, inelastic Coulomb scattering by electrical action occurred with the highest frequency of 99.02%, and elastic collisions, nuclear inelastic collisions, and multiple Coulomb scatterings appeared with low frequencies of 0.633%, 0.334%, and 0.006%, respectively. The use of gold as the enhancement material increased the frequency of interactions by a factor of 1.14–1.18 for inelastic Coulomb scattering, 1.05–1.30 for elastic collision, and 1.03–1.37 for nuclear inelastic collision. Furthermore, the use of gadolinium as the enhancement material increased the frequency of interactions by a factor of 1.08–1.14 for inelastic Coulomb scattering, 1.03–1.25 for elastic collision, and 1.01–1.34 for nuclear inelastic collision. Regarding the dose by the production of secondary particles, the equivalent dose increased by a factor of 1.032–1.070 for alpha particles, 1.133–1.860 for neutrons, and 1.030–1.053 for deuterons when gold was used as the enhancement material. When gadolinium was used as the enhancement material, the equivalent dose increased by a factor of 1.015–1.043 for alpha particles, 1.075–1.478 for neutrons, and 1.021–1.036 for deuterons. Conclusions Based on this study’s findings, the dose enhancement simulations correspond to the physical characteristics of energy transmission. The study’s results can be used as basic data for in vivo and in vitro experiments investigating the effects of dose enhancement.

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“…In general, neutron doses are much lower than the total deposited dose by the incoming particles. It has been reported that the neutron dose at the Bragg peak depth in the water phantom cannot exceed 0.7% of the total dose for protons with 70 MeV energies [36].…”

Section: Conclusion and Commentmentioning

confidence: 99%

The Effect of Proton and Helium Ions on Secondary Neutron Production in the Slab Head Phantom

Pehlivanli

Bölükdemir

2021

Süleyman Demirel Üniversitesi Fen Edebiyat Fakültesi Fen Dergisi

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Particle therapy (PT) usually uses protons and carbon ions. In addition, the use of low-Z ions (such as He, O, Ne) with higher relative biological effects than protons is also being investigated. Although in PT the majority of the dose is delivered to the tumor volume by the primary particle, a negligible additional dose is left due to the contribution of secondary particles produced by the interaction between the therapeutic beam and the patient's tissues. In particular, neutrons can increase the risk of secondary cancer by transferring energy far away from the treated area. To use charged particles in radiation therapy, it is crucial to characterize secondary neutrons produced (SNP) as a result of primary particle interactions with human tissue. The SNP can be detected with the detector or by methods such as Monte Carlo (MC) simulation. In our study, the total number of neutrons produced in the slab head phantom by proton and He ion beams with an energy of 50-100 MeV/u, the doses stored by neutrons and all other particles were calculated with the Particle and Heavy Ion Transport Code System (PHITS) MC code. The number of SNP by He ion beam increased 7-14 times compared to proton beams. It was calculated that the doses of the SNP by protons were between 11.5% - 16.4% of those in the He ion beams.

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The determination of a dose deposited in reference medium due to (p,n) reaction occurring during proton therapy

Cited by 8 publications

References 14 publications

On the (un)effectiveness of proton boron capture in proton therapy

On the (un)effectiveness of proton boron capture in proton therapy

Secondary particle production and physical properties during dose enhancement for spread-out Bragg peaks

The Effect of Proton and Helium Ions on Secondary Neutron Production in the Slab Head Phantom

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