Optimization of an accelerator-based epithermal neutron source for neutron capture therapy

Kononov, O. E.; Kononov, V.N.; Bokhovko, M.V.; Korobeynikov, V. V.; Soloviev, Alexander N.; Sysoev, A.S; Гулидов, И. А.; Chu, W. T.; Nigg, David W.

doi:10.1016/j.apradiso.2004.05.028

Cited by 54 publications

(23 citation statements)

References 6 publications

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“…The collimator was built in lead with four straight bores 0.5 cm diameter and 30 cm length providing a geometrical spatial resolution of 1 cm at a distance of 30 cm. The shielding has been constructed with successive layers, from outside to inside: a layer of a mixture of paraffin and lithium carbonate to moderate and absorb neutrons; a cadmium layer for further shielding of thermal neutrons; a lead layer for shielding gammas and a final layer of lithium carbonate enriched in 6 Li for absorbing the remaining thermal neutrons. The whole system was mounted on motorized rails remotely controlled.…”

Section: System Design and Testing Of A Prototypementioning

confidence: 99%

“…In this scenario, accelerator-based neutron sources, installed in specialized cancer centers, will play a decisive role in the future of BNCT. Therefore several programs, whose number has increased during the last few years, are dedicated to the development of accelerator-based BNCT (AB-BNCT): two in Japan [3,4], two in Russia [5,6], one in Israel [7], one in Italy [8], one in the United Kingdom [9] and one in Argentina [10].…”

Section: Introductionmentioning

confidence: 99%

“…The lithium reaction was traditionally considered the best due to its neutron yield and because it can produce low energy neutrons at bombarding energies near its threshold (1.88 MeV). However the most awkward properties of lithium for constructing high-power targets are its chemical reactivity, low melting point (180º), low thermal conductivity (85 W·m -1 ·K -1 ) and management of the radioactive product generated in the reaction ( 7 Be, T 1/2 = 53.2 days), though these are not insurmountable problems [5,6,7,9]. In this paper we report on the present status of an ongoing project to develop a folded Tandem-Electrostatic-Quadrupole (TESQ) accelerator facility for AB-BNCT at the Atomic Energy Commission of Argentina (CNEA) [11].…”

Section: Introductionmentioning

confidence: 99%

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Accelerator technology and SPECT developments for BNCT

Valda¹

2014

Proceedings of 10th Latin American Symposium on Nuclear Physics and Applications — PoS(X LASNPA)

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Accelerator-Based Boron Neutron Capture Therapy (AB-BNCT) is establishing itself worldwide as the future modality to start the phase of in-hospital facilities. There are projects in Russia, UK, Italy, Japan, Israel and Argentina to develop AB-BNCT around different types of accelerators. In particular, the present status and recent progress of the Argentine project for the development of a Tandem-Electrostatic-Quadrupole (TESQ) accelerator is presented. Different working areas are treated: high-power ion sources, acceleration tubes, transport of intense beams, beam diagnostics, high-power targets, 9 Be(d,n) reaction as a possible neutron source and treatment room design. A complete test stand was built and commissioned for intense proton beam production and characterization. Beams of 10 to 30 mA have been produced and transported during variable periods of operation by means of a pre accelerator and an electrostatic quadrupole doublet to a suppressed Faraday cup. The beam diagnostics has been performed through the observation with digital cameras of induced fluorescence in the residual gas. A 200 kV TESQ accelerator prototype has been constructed and is under test and a 600 keV prototype is under construction. Self consistent space charge beam transport simulations have been performed and compared with experiments. In addition to the traditional 7 Li(p,n) reaction, 9 Be(d,n) using a thin Be target has been thoroughly studied as a candidate for a possible neutron source for deep seated tumors, showing a satisfactory performance. A treatment room complying with regulations has been designed. Finally we present advances in the development of a SinglePhoton Emission Computed Tomography (SPECT) system for online dosimetry during a BNCT treatment.

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Section: System Design and Testing Of A Prototypementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Accelerator technology and SPECT developments for BNCT

Valda¹

2014

Proceedings of 10th Latin American Symposium on Nuclear Physics and Applications — PoS(X LASNPA)

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“…the accelerator target placed at the center and a simplified model of a phantom of a human head in the form of a cube with 20 cm edge length in which the two 0.5 and 0.8 cm thick front layers simulate the skin and skull, respectively, and the rest of the volume is brain material. The composition of the tissues and structure of the detectors are presented in [13].…”

mentioning

confidence: 99%

“…It should not exceed ~2.8·10 -12 Gy·cm 2 [3]. The kerma and the relative biological efficiency were used for calculating the biologically weighted absorbed dose [13]. Various materials consisting of elements with large scattering cross section for fast neutrons and small absorption cross section and low activation in the slow neutron range and their accessible compounds in the form of oxides, nitrides, and fluorides were used.…”

mentioning

confidence: 99%

Accelerator-based source of epithermal neutrons for neutron capture therapy

Kononov

Solovev

et al. 2004

At Energy

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Computational studies are performed for choosing an optimal material and dimensions of a moderator for forming a beam of epithermal neutrons for boron-neutron-capture therapy based on a proton accelerator and the reaction 7 Li(p, n) 7 Be as the neutron source. It is shown that the best material for this is magnesium fluoride. An optimal configuration is proposed for a combined moderator consisting of magnesium fluoride and teflon. The computational results are compared with the experimental data.Neutron capture therapy, whose fundamental feature is selectivity of the radiation damage to cancer cells, is now regarded as a promising method for treating certain malignant tumors, specifically, various forms of brain tumors. Although the therapeutic effect in this method is based on the radiation action of the products of nuclear reactions, produced by thermal neutrons in strongly neutron-absorbing nuclides, such as 10 B and 157 Gd, the low penetration power of thermal neutrons in tissue limits their application to tumors located near the surface or to irradiating internal organs during an operation. For many deep-lying tumors, it is better to use epithermal neutrons in the energy range 1 eV-10 keV whose penetration power is much higher. Moderated in the tissue to thermal energy, they permit neutron-capture therapy on tumors located at depths up to 10 cm. Here it is important that the number of fast neutrons in the epithermal-neutron spectrum, which limit the possible achievable therapeutic dose in the tumor, be small. As a rule, the maximum admissable radiation load in the outer layers, which is produced by fast neutrons, is a limitation. Epithermal-neutron beams with dimension 10 × 10 cm and flux densitỹ 10 9 sec -1 ·cm -2 are needed to perform clinical studies and treatment. Several facilities where the spatial-energy formation of the epithermal-neutron beam is performed with a complicated system of moderators, filters, collimators, and shielding have now been developed on the basis of nuclear reactors [1][2][3][4]. A epithermal neutron beam with the best characteristics for neutron-capture therapy today has been produced on the basis of the 5-MW MITR II reactor (USA) [2][3][4]. In this facility, the reactor thermal-neutron flux is converted by a 235 U converter into a fission-neutron flux from which the epithermal-neutron beam is then formed. Although the nuclear reactor as an intense neutron source for radiotherapy possesses important advantages, such as high neutron flux density in space and time, the development of a series of such facilities for wide application is unrealistic even in large oncological centers because of nuclear-safety considerations, high capital costs, and operational longevity.In this connection, the development of a neutron source for neutron-capture therapy based on an inexpensive proton accelerator with energy 2-3 MeV with beam power 10-20 kW, intended for use in oncological clinics, has been widely discussed and investigated for the last 10 years [5][6][7][8]. The reaction 7 Li(p, n)...

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Efficient optimization of an accelerator neutron source for neutron capture therapy using genetic algorithms

Ge,

Zhong,

Murata

et al. 2024

Medical Physics

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BackgroundIn recent years, genetic algorithms have been applied in the field of nuclear technology design, producing superior optimization results compared to traditional methods. They can be employed in the design and optimization of beam shaping assemblies (BSA) BSA to obtain the desired neutron beams. But it should be noted that the direct combination of Monte Carlo methods with genetic algorithms requires a significant amount of computational resources and time.PurposeDesign and optimize BSA more efficiently to achieve neutron beams that meet specified recommendations.MethodsWe propose an approach of NSGA II with crucial variables which are identified by multivariate statistical techniques. This approach significantly reduces the problem sizes, thus reducing the time required for optimization. We illustrate this methodology using the example of BSA design for AB‐BNCT.ResultsThe computational efficiency has tripled with crucial variables. By using NSGA II, we obtained optimized models conforming to both the new and old version IAEA BNCT guidelines through a single optimization process and subjected them to phantom analysis. The results demonstrate that models obtained through this method can meet the IAEA recommendations with deep advantage depth (AD) and high absorbed ratio (AR).ConclusionThe genetic algorithm with crucial variables displays tremendous potential in addressing BSA optimization challenges.

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Optimization of an accelerator-based epithermal neutron source for neutron capture therapy

Cited by 54 publications

References 6 publications

Accelerator technology and SPECT developments for BNCT

Accelerator technology and SPECT developments for BNCT

Accelerator-based source of epithermal neutrons for neutron capture therapy

Efficient optimization of an accelerator neutron source for neutron capture therapy using genetic algorithms

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