CN205339881U - Beam shaper for neutron -capture therapy - Google Patents
Beam shaper for neutron -capture therapy Download PDFInfo
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- CN205339881U CN205339881U CN201520955634.2U CN201520955634U CN205339881U CN 205339881 U CN205339881 U CN 205339881U CN 201520955634 U CN201520955634 U CN 201520955634U CN 205339881 U CN205339881 U CN 205339881U
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Abstract
Penetrate the flux and the quality in source in order to improve the neutron, the utility model discloses an aspect provides a beam shaper for neutron -capture therapy, wherein, the beam shaping body is including the beam entry, the target, border on in the slow fast body of target, the encirclement is at the external reflector of slowly inviting, personally experience sth. Part of the body with the thermal neutron absorption that the slow fast body borders on, the setting is at internal radiation shield and the beam outlet of beam shaping, the nuclear reaction takes place in order to produce the neutron with the proton beam that incides from the beam entry for the target, the neutron forms the neutron beam, a main shaft is injectd to the neutron beam, delay the fast body subzone to the super -heated in of will slowing down from the neutron that the target produced, delay the fast body and set the shape that contains at least one cone form to, it has the main part and surrounds the additional portion in the main part periphery to delay the fast body, the material of replenishment portion is different with the material of main part, and the main shaft is led back in order improving super -heated neutron beam intensity to neutron that the reflector will deviate the main shaft, the thermal neutron absorption body and function in the absorption heat neutron when avoiding the treatment and the shallow layer normal structure cause too much dosage, neutron and photon that the radiation shield is used for shielding the seepage are in order to reduce the normal structure dosage that non - shines the district.
Description
Technical field
This utility model relates to a kind of beam-shaping body, particularly relates to a kind of beam-shaping body for neutron capture treatment.
Background technology
Development along with atomics, for instance one of radiation cure Main Means becoming treatment of cancer such as cobalt 60, linear accelerator, electron beam.But conventional photonic or electronic therapy are subject to the restriction of the physical condition of lonizing radiation own, while killing tumor cell, also normal structure substantial amounts of in beam approach can be damaged；Additionally, due to the tumor cell difference to lonizing radiation sensitivity, traditional radiation therapy is often not good for the treatment effect relatively having the malignant tumor (such as multirow glioblastoma multiforme (glioblastomamultiforme), melanocytoma (melanoma)) of radiation resistance.
In order to reduce the radiation injury of tumor surrounding normal tissue, the target therapy concept in chemotherapy (chemotherapy) is just applied in radiation cure；And for the tumor cell of radiation resistance, currently also actively development has the radiation source of high relative biological effect (relativebiologicaleffectiveness, RBE), such as proton therapeutic, heavy particle therapy, neutron capture treatment etc..Wherein, neutron capture treatment is in conjunction with above two concept, as boron neutron capture is treated, gathers at the specificity of tumor cell by boracic medicine, coordinates neutron beam regulation and control accurately, it is provided that more better treatment of cancer selection than conventional radiation.
Boron neutron capture treatment (BoronNeutronCaptureTherapy, BNCT) be utilize boracic (10B) thermal neutron is had the characteristic of high capture cross section by medicine, by10B(n,α)7Li neutron capture and karyokinesis reaction produce4He and7Two heavy burden charged particle of Li.See figures.1.and.2, which respectively show boron neutron capture reaction schematic diagram and10B(n,α)7Li neutron capture nuclear equation formula, the average energy of two charged particles is about 2.33MeV, has High Linear transfer (LinearEnergyTransfer, LET), short range feature, the linear energy transfer of alpha-particle and range respectively 150keV/ μm, 8 μm, and7Li heavy burden particle is then 175keV/ μm, 5 μm, the integrated range of two particle is approximately equivalent to a cell size, therefore the radiation injury caused for organism can be confined to cell level, when boracic drug selectivity be gathered in tumor cell, suitable neutron of arranging in pairs or groups penetrates source, just can cause under the premise of too major injury at not normal tissue, reach local and kill the purpose of tumor cell.
Because the effect of boron neutron capture treatment depends on tumor cell position boracic drug level and thermal neutron quantity, therefore binary lonizing radiation treatment of cancer (binarycancertherapy) that is otherwise known as；It follows that except the exploitation of boracic medicine, neutron is penetrated source flux and is occupied key player with improving of quality in the research of boron neutron capture treatment.
Utility model content
Flux and the quality in source is penetrated in order to improve neutron, an aspect of the present utility model provides a kind of beam-shaping body for neutron capture treatment, wherein, beam-shaping body includes beam entrance, target, it is adjacent to the slow body of target, it is enclosed in reflector external slowly, the thermal neutron absorber adjacent with slow body, it is arranged on the radiation shield in beam-shaping body and beam outlet, target and the proton beam generation nuclear reaction incident from beam entrance are to produce neutron, neutron forms neutron beam, neutron beam limits a main shaft, slow body by the neutron degradation that produces from target to epithermal neutron energy district, slow body is arranged to comprise at least one pyramidal shape, described slow body has main part and is enclosed in the supplementary portion of main part periphery, the material of described supplementary portion is different from the material of main part, reflector will deviate from the neutron of main shaft and leads back to main shaft to improve epithermal neutron intensity of beam, thermal neutron absorber is used for when absorbing thermal neutron to avoid treating to cause multiple dose with shallow-layer normal structure, radiation shield is used for shielding the neutron of seepage and photon to reduce the normal tissue dose in non-irradiated district.
Further, described main part includes being adjacent to the cone portion of target and being adjacent to the trunk portion of cone portion, and described supplementary portion is coated on the external peripheral surface of trunk portion and is connected with cone portion thus being collectively forming described cone-shaped with cone portion.
Beam-shaping body is further used for the treatment of accelerator boron neutron capture.
Proton beam is accelerated by the treatment of accelerator boron neutron capture by accelerator, and target is made of metal, and proton beam accelerates to the energy being enough to overcome target atom core coulomb repulsion, with target generation nuclear reaction to produce neutron.
Beam-shaping physical ability by neutron slowly to epithermal neutron energy district, and reduce thermal neutron and fast neutron content, epithermal neutron energy district is between 0.5eV to 40keV, hanker subzone less than 0.5eV, fast-neutron range is more than 40keV, slow body is made by having the material that fast neutron action section is big, epithermal neutron action section is little, and reflector is made up of the material having neutron reflection ability strong, and thermal neutron absorber is made up of the material big with thermal neutron action section.
As one preferably, slow body is by D2O、AlF3、FluentalTM、CaF2、Li2CO3、MgF2And Al2O3In any one make, reflector is made up of any one in Pb or Ni, thermal neutron absorber by6Li makes, and is provided with air duct between thermal neutron absorber and beam outlet, and radiation shield includes photon shielding and neutron shield.As one preferably, photon shielding is made up of Pb, and neutron shield is made up of PE (polyethylene).
As one preferably, supplementary portion is made up of any one in Zn, Mg, Al, Ti, La, Pb, Zr and Bi.
As one preferably, slow body be arranged to comprise a bar shape and a pyramidal shape adjacent with bar shape or be arranged to that two rightabouts adjoin each other cone-shaped.
Further, described main part includes trunk portion and be positioned at trunk portion two ends the cone portion being connected with trunk portion two ends, described supplementary portion be coated on trunk portion periphery and be connected with two cone portion and make slow body be rightabout adjoin each other cone-shaped.
" cylinder " or " bar shape " described in the embodiment of the present application refers to the structure being basically unchanged along the side of direction as shown to the overall trend of its outline of opposite side, a wherein contour line of outline can be line segment, corresponding contour line such as cylindrical shape, it can also be the circular arc close to line segment that curvature is bigger, the corresponding contour line of sphere body shape as bigger in curvature, the whole surface of outline can be rounding off, can also being non-rounding off, a lot of projection and groove have been done in the surface such as the sphere body shape bigger at cylindrical shape or curvature.
" cone " or " cone-shaped " described in the embodiment of the present application refers to the structure tapered into along the side of direction as shown to the overall trend of its outline of opposite side, a wherein contour line of outline can be line segment, corresponding contour line such as cone shape, it can also be circular arc, corresponding contour line such as sphere body shape, the whole surface of outline can be rounding off, it is also possible to be non-rounding off, as done a lot of projection and groove on the surface of cone shape or sphere body shape.
Accompanying drawing explanation
Fig. 1 is boron neutron capture reaction schematic diagram.
Fig. 2 is10B(n,α)7Li neutron capture nuclear equation formula.
Fig. 3 is the floor map of the beam-shaping body for neutron capture treatment in the application first embodiment, wherein, is provided with clearance channel between slow body and reflector.
Fig. 4 is the floor map of the beam-shaping body for neutron capture treatment in the application the second embodiment, and wherein, slow body is arranged to bicone, and the clearance channel position in first embodiment is filled with slow body material.
Fig. 5 is the floor map of the beam-shaping body for neutron capture treatment in the application the 3rd embodiment, and wherein, slow body is arranged to bicone, and the clearance channel position in first embodiment is filled with reflector material.
Fig. 6 is the neutron yield rate figure of neutron energy and the double; two differential of neutron angle.
Fig. 7 is the floor map of the beam-shaping body for neutron capture treatment in the application the 4th embodiment, and wherein, slow body is arranged to cylinder.
Fig. 8 is the floor map of the beam-shaping body for neutron capture treatment in the application the 5th embodiment, and wherein, slow body is arranged to cylinder+cone.
Fig. 9 is the floor map of the beam-shaping body for neutron capture treatment in the application sixth embodiment, and wherein bicone shape includes main part and the supplementary portion of different materials.
Figure 10 is the floor map of the beam-shaping body for neutron capture treatment in the application the 7th embodiment, wherein, is set to cone+cylinder in slow body, and cone is formed by main part and the supplementary portion of different materials.
Detailed description of the invention
Neutron capture is treated the application in recent years of the means as a kind of effective treatment cancer and is gradually increased, wherein most commonly seen with the treatment of boron neutron capture, and the neutron of supply boron neutron capture treatment can by nuclear reactor or accelerator supply.Embodiments herein is treated for accelerator boron neutron capture, the basic module of accelerator boron neutron capture treatment generally includes the accelerator for charged particle (such as proton, deuteron etc.) is accelerated, target and hot removal system and beam-shaping body, wherein accelerate charged particle and produce neutron with metal targets effect, according to required neutron yield rate and energy, available acceleration charged particle energy and size of current, metal targets the characteristic such as materialization select suitable nuclear reaction, the nuclear reaction often come into question has7Li(p,n)7Be and9Be(p,n)9B, both reactions are all the endothermic reaction.The energy threshold of two kinds of nuclear reactions respectively 1.881MeV and 2.055MeV, the epithermal neutron that desirable neutron source is keV energy grade due to the treatment of boron neutron capture, if using energy to be only slightly taller than the proton bombardment lithium metal target of threshold values in theory, the neutron of relative mental retardation can be produced, it is not necessary to too many slow process and just can be used for clinic, but lithium metal (Li) and two kinds of targets of beryllium metal (Be) are not high with the proton-effect cross section of threshold values energy, for producing sufficiently large neutron flux, the proton of higher-energy is generally selected to carry out initiated core reaction.
Desirable target should possess high neutron yield rate, the neutron energy of generation is distributed close to epithermal neutron energy district (will be described in more detail below), without too many wear by force radiation produce, the safety cheaply characteristic such as easily operated and high temperature resistant, but actually and cannot find and meet the nuclear reaction required, embodiments herein adopts the metal target of lithium.But well known to those skilled in the art, the material of target can also be made up of other metal materials except the above-mentioned metal material talked about.
Requirement for hot removal system is then different according to the nuclear reaction selected, as7Li(p,n)7Be is poor because of fusing point and the thermal conductivity coefficient of metal targets (lithium metal), to the requirement of hot removal system just relatively9Be(p,n)9B is high.Embodiments herein adopts7Li(p,n)7The nuclear reaction of Be.
No matter the neutron source of boron neutron capture treatment is from the nuclear reaction of nuclear reactor or accelerator charged particle with target, generation be all mixed radiation field, namely beam contains mental retardation to the neutron of high energy, photon；Boron neutron capture for deep tumor is treated, and except epithermal neutron, remaining radiation content is more many, causes the ratio that the non-selective dosage of normal structure deposits more big, and therefore these can cause the radiation of unnecessary dosage to reduce as far as possible.Except air beam quality factor, for knowing more about the dose distribution that neutron causes in human body, embodiments herein uses human body head tissue prosthesis carry out Rapid Dose Calculation, and be used as the design reference of neutron beam with prosthese beam quality factor, will be described in more detail below.
International Atomic Energy Agency (IAEA) is for the neutron source of clinical boron neutron capture treatment, advise given five air beam quality factors, these five suggestions can be used for the quality of the different neutron source of comparison, and is provided with as reference frame when selecting neutron the way of production, design beam-shaping body.These five suggestions are as follows respectively:
Epithermal neutron beam flux Epithermalneutronflux > 1x109n/cm2s
Fast neutron pollutes Fastneutroncontamination < 2x10-13Gy-cm2/n
Photon contamination Photoncontamination < 2x10-13Gy-cm2/n
Thermal and epithermal neutron flux ratio thermaltoepithermalneutronfluxratio < 0.05
Middle electron current and flux ratio epithermalneutroncurrenttofluxratio > 0.7
Note: epithermal neutron energy district, between 0.5eV to 40keV, hankers subzone less than 0.5eV, and fast-neutron range is more than 40keV.
1, epithermal neutron beam flux:
In neutron beam flux and tumor, boracic drug level has together decided on the clinical treatment time.If the enough height of tumor boracic drug level, the requirement for neutron beam flux just can reduce；Otherwise, if boracic drug level is low in tumor, then need high flux epithermal neutron to give the dosage that tumor is enough.IAEA for the epithermal neutron number that requirement is every square centimeter per second of epithermal neutron beam flux more than 109, the neutron beam under this flux can substantially control treatment time in one hour for current boracic medicine, and short treatment time is except having superiority to patient location and comfort level, it is possible to more effectively utilize the holdup time that boracic medicine is limited in tumor.
2, fast neutron pollutes:
Owing to fast neutron can cause unnecessary normal tissue dose, what therefore look is pollute, and this dosage size and neutron energy are proportionate, and therefore should reduce the content of fast neutron on neutron beam designs as far as possible.Fast neutron pollutes and is defined as the fast neutron dosage that unit epithermal neutron flux is adjoint, and the suggestion that fast neutron is polluted by IAEA is less than 2x10-13Gy-cm2/n。
3, photon contamination (gamma-ray contamination):
Gamma-rays belongs to wears by force radiation, can non-selectively cause institute's organized dosage deposition on course of the beam, therefore the exclusive requirement that gamma-rays content is also neutron beam design is reduced, gamma-ray contamination is defined as the gamma-rays dosage that unit epithermal neutron flux is adjoint, and the suggestion of gamma-ray contamination is less than 2x10 by IAEA-13Gy-cm2/n。
4, thermal and epithermal neutron flux ratio:
Owing to thermal neutron decay speed is fast, penetration capacity is poor, after entering human body, major part energy deposition is at skin histology, except need to using the neutron source that thermal neutron is treated as boron neutron capture except Several Epidermal Tumors such as melanocytomas, thermal neutron content should be reduced for deep tumor such as cerebromas.The suggestion of thermal and epithermal neutron flux ratio is less than 0.05 by IAEA.
5, middle electron current and flux ratio:
Middle electron current and flux ratio represent the directivity of beam, and before the more big expression neutron beam of ratio, tropism is good, and before high, the neutron beam of tropism can reduce because neutron disperses the normal surrounding tissue dosage caused, and additionally also improve and can treat the degree of depth and pendulum pose gesture elasticity.IAEA centering electron current and flux ratio suggestion are for more than 0.7.
Prosthese is utilized to obtain in-house dose distribution, the dose versus depth curve according to normal structure and tumor, push away to obtain prosthese beam quality factor.Following three parameter can be used for carrying out the comparison of different neutron beam treatment benefit.
1, effective therapeutic depth:
Tumor dose is equal to the degree of depth of normal structure maximal dose, and the position after this degree of depth, the dosage that tumor cell obtains, less than normal structure maximal dose, namely loses the advantage of boron neutron capture.This parameter represents the penetration capacity of neutron beam, and the effective therapeutic depth medicable tumor depth of more big expression is more deep, and unit is cm.
2, effective therapeutic depth close rate:
The i.e. tumor dose rate of effective therapeutic depth, also equal to the maximum dose rate of normal structure.Being that impact can give the factor of tumor accumulated dose size because normal structure receives accumulated dose, therefore parameter affects the length for the treatment of time, the more big expression of effective therapeutic depth close rate give tumor doses needed for irradiation time more short, unit is cGy/mA-min.
3, dose therapeutically effective ratio:
From brain surface to effective therapeutic depth, the mean dose ratio that tumor and normal structure receive, it is referred to as dose therapeutically effective ratio；The calculating of mean dose, can be obtained by dose versus depth curvilinear integral.Dose therapeutically effective ratio is more big, and the treatment benefit representing this neutron beam is more good.
Compare foundation to make beam-shaping body have in design, except beam quality factor and above-mentioned three parameters in the air of five IAEA suggestions, the embodiment of the present application also utilize the following parameter good and bad for assessing the performance of neutron beam dosage:
1, irradiation time≤30min (the proton electric current that accelerator uses is 10mA)
2,30.0RBE-Gy can treat the degree of depth >=7cm
3, tumor maximal dose >=60.0RBE-Gy
4, normal cerebral tissue's maximal dose≤12.5RBE-Gy
5, skin maximal dose≤11.0RBE-Gy
Note: RBE (RelativeBiologicalEffectiveness) is relative biological effect, the biological effect that can cause due to photon, neutron is different, so dosage item as above is multiplied by the relative biological effect of different tissues respectively in the hope of dose,equivalent.
Penetrate flux and the quality in source to improve neutron, embodiments herein is the improvement proposed for the beam-shaping body treated for neutron capture, as one preferably, is the improvement for the beam-shaping body treated for accelerator boron neutron capture.As shown in Figure 3, the beam-shaping body 10 for neutron capture treatment in the application first embodiment, it includes beam entrance 11, target 12, it is adjacent to the slow body 13 of target 12, it is enclosed in the reflector 14 outside slow body 13, the thermal neutron absorber 15 adjacent with slow body 13, it is arranged on the radiation shield 16 in beam-shaping body 10 and beam outlet 17, target 12 and the proton beam generation nuclear reaction from beam entrance 11 incidence are to produce neutron, neutron forms neutron beam, neutron beam limits a major axis X, slow body 13 by the neutron degradation that produces from target 12 to epithermal neutron energy district, reflector 14 will deviate from the neutron of major axis X and leads back to major axis X to improve epithermal neutron intensity of beam, clearance channel 18 is set between slow body 13 and reflector 14 to improve epithermal neutron flux, thermal neutron absorber 15 is used for when absorbing thermal neutron to avoid treating to cause multiple dose with shallow-layer normal structure, radiation shield 16 is used for shielding the neutron of seepage and photon to reduce the normal tissue dose in non-irradiated district.
Proton beam is accelerated by the treatment of accelerator boron neutron capture by accelerator, and as a kind of preferred embodiment, target 12 is made up of lithium metal, and proton beam accelerates to the energy being enough to overcome target atom core coulomb repulsion, occurs with target 127Li(p,n)7Be nuclear reaction is to produce neutron.Beam-shaping body 10 by neutron slowly to epithermal neutron energy district, and can reduce thermal neutron and fast neutron content, and slow body 13 is made by having the material that fast neutron action section is big, epithermal neutron action section is little, and as a kind of preferred embodiment, slow body 13 is by D2O、AlF3、FluentalTM、CaF2、Li2CO3、MgF2And Al2O3In at least one make that (slow body 13 is by D2O、AlF3、FluentalTM、CaF2、Li2CO3、MgF2And Al2O3In at least one make and certainly also include slow body 13 by D2O、AlF3、FluentalTM、CaF2、Li2CO3、MgF2And Al2O3In any one situation about making).Reflector 14 is made up of the material having neutron reflection ability strong, as a kind of preferred embodiment, reflector 14 is made (certainly also being included the situation that reflector 14 is made up of any one in Pb or Ni by least one the making in Pb or Ni described in reflector 14) by least one in Pb or Ni.Thermal neutron absorber 15 is made up of the material big with thermal neutron action section, as a kind of preferred embodiment, thermal neutron absorber 15 by6Li makes, and is provided with air duct 19 between thermal neutron absorber 15 and beam outlet 17.Radiation shield 16 includes photon shielding 161 and neutron shield 162, and as a kind of preferred embodiment, radiation shield 16 includes the photon shielding 161 being made up of plumbous (Pb) and the neutron shield 162 being made up of polyethylene (PE).
Wherein, it is cone-shaped that slow body 13 is arranged to that two rightabouts adjoin each other, direction as shown in Figure 3, and the left side of slow body 13 is taper into towards left side cone-shaped, and the right side of slow body 13 is taper into towards right side cone-shaped, and both adjoin each other.As one preferably, it is cone-shaped that the left side of slow body 13 is set to taper into towards left side, and right side can also be arranged to its allothimorph shape and cone-shaped adjoin each other with this, such as bar shape etc..Reflector 14 is enclosed in around slow body 13 closely, it is provided with clearance channel 18 between slow body 13 and reflector 14, so-called clearance channel 18 refers to the empty region easily allowing neutron beam pass through that unused solid material covers, as this clearance channel 18 could be arranged to air duct or vacuum passage.It is close to the thermal neutron absorber 15 of slow body 13 setting by very thin one layer6Li material is made, and the photon being made up of the Pb shielding 161 in radiation shield 16 can be set to one with reflector 14, it is also possible to be arranged to split, and the neutron shield 162 being made up of PE in radiation shield 16 can be positioned adjacent to the position of beam outlet 17.Exporting at thermal neutron absorber 15 and beam and be provided with air duct 19 between 17, in this region, the sustainable neutron that will deviate from major axis X leads back to major axis X to improve epithermal neutron intensity of beam.Prosthese B is arranged on distance beam outlet 17 about 1cm place.Well known to those skilled in the art, photon shielding 161 can be made up of other materials, as long as playing the effect of shielding photon, neutron shield 162 can also be made up of other materials, can also be arranged on other local, as long as disclosure satisfy that the condition of shielding seepage neutron.
The difference of the beam-shaping body in order to compare the beam-shaping body being provided with clearance channel and be not provided with clearance channel, as shown in Figure 4 and Figure 5, which respectively show the second embodiment adopting slow body to fill clearance channel and the 3rd embodiment adopting reflector to fill clearance channel.With reference first to Fig. 4, this beam-shaping body 20 includes beam entrance 21, target 22, it is adjacent to the slow body 23 of target 22, it is enclosed in the reflector 24 outside slow body 23, the thermal neutron absorber 25 adjacent with slow body 23, it is arranged on the radiation shield 26 in beam-shaping body 20 and beam outlet 27, target 22 and the proton beam generation nuclear reaction from beam entrance 21 incidence are to produce neutron, neutron forms neutron beam, neutron beam limits a major axis X 1, slow body 23 by the neutron degradation that produces from target 22 to epithermal neutron energy district, reflector 24 will deviate from the neutron of major axis X 1 and leads back to major axis X 1 to improve epithermal neutron intensity of beam, it is cone-shaped that slow body 23 is arranged to that two rightabouts adjoin each other, the left side of slow body 23 is taper into towards left side cone-shaped, the right side of slow body 23 is taper into towards right side cone-shaped, both adjoin each other, thermal neutron absorber 25 is used for when absorbing thermal neutron to avoid treating to cause multiple dose with shallow-layer normal structure, radiation shield 26 is used for shielding the neutron of seepage and photon to reduce the normal tissue dose in non-irradiated district.
As one preferably, target 22 in second embodiment, slow body 23, reflector 24, thermal neutron absorber 25 can be identical with first embodiment with radiation shield 26, and radiation shield 26 therein includes the photon shielding 261 being made up of plumbous (Pb) and the neutron shield 262 being made up of polyethylene (PE), this neutron shield 262 can be arranged on beam and export 27 places.Export at thermal neutron absorber 25 and beam and be provided with air duct 28 between 27.Prosthese B1 is arranged on distance beam outlet 27 about 1cm place.
Refer to Fig. 5, this beam-shaping body 30 includes beam entrance 31, target 32, it is adjacent to the slow body 33 of target 32, it is enclosed in the reflector 34 outside slow body 33, the thermal neutron absorber 35 adjacent with slow body 33, it is arranged on the radiation shield 36 in beam-shaping body 30 and beam outlet 37, target 32 and the proton beam generation nuclear reaction from beam entrance 31 incidence are to produce neutron, neutron forms neutron beam, neutron beam limits a major axis X 2, slow body 33 by the neutron degradation that produces from target 32 to epithermal neutron energy district, reflector 34 will deviate from the neutron of major axis X 2 and leads back to major axis X 2 to improve epithermal neutron intensity of beam, it is cone-shaped that slow body 33 is arranged to that two rightabouts adjoin each other, the left side of slow body 33 is taper into towards left side cone-shaped, the right side of slow body 33 is taper into towards right side cone-shaped, both adjoin each other, thermal neutron absorber 35 is used for when absorbing thermal neutron to avoid treating to cause multiple dose with shallow-layer normal structure, radiation shield 36 is used for shielding the neutron of seepage and photon to reduce the normal tissue dose in non-irradiated district.
As one preferably, target 32 in 3rd embodiment, slow body 33, reflector 34, thermal neutron absorber 35 can be identical with first embodiment with radiation shield 36, and radiation shield 36 therein includes the photon shielding 361 being made up of plumbous (Pb) and the neutron shield 362 being made up of polyethylene (PE), this neutron shield 362 can be arranged on beam and export 37 places.Export at thermal neutron absorber 35 and beam and be provided with air duct 38 between 37.Prosthese B2 is arranged on distance beam outlet 37 about 1cm place.
Adopt MCNP software (being the common software bag for the neutron calculating in 3 D complex geometry, photon, charged particle or coupling neutron/photon/charged particle transport problem based on DSMC developed by Los Alamos National Laboratories of the U.S. (LosAlamosNationalLaboratory)) that the simulation of these three embodiment is calculated below:
Wherein, as following table one illustrates beam quality factor performance (in form, each name lexeme is same as above, does not repeat them here, lower same) in these three embodiment in air:
Table one: beam quality factor in air
Wherein, as following table two illustrates the performance in the present these three embodiment of dose form:
Table two: dosage shows
| Dosage shows | Slow body fills clearance channel | Reflector fills clearance channel | Clearance channel |
| Effective therapeutic depth | 10.9 | 10.9 | 11.0 |
| Effective therapeutic depth close rate | 4.47 | 4.60 | 4.78 |
| Dose therapeutically effective ratio | 5.66 | 5.69 | 5.68 |
Wherein, as following table three illustrates the parameter of assessment neutron beam dosage performance quality simulation value in these three embodiment:
Table three: the parameter that assessment neutron beam dosage performance is good and bad
Note: being appreciated that from three above-mentioned tables: be provided with the beam-shaping body of clearance channel between slow body and reflector, the treatment benefit of its neutron beam is best.
Neutron owing to producing from lithium target has the characteristic that Forward averaging energy is higher, as shown in Figure 6, neutron scattering angle average neutron energy between 0 °-30 ° is about 478keV, and the average neutron energy that neutron scattering angle is between 30 °-180 ° about only has 290keV, if can by the geometry changing beam-shaping body, forward direction neutron is made to produce more collision with slow body, and laterally neutron just can arrive beam outlet through less collision, then should reach the slow optimization of neutron, efficient raising epithermal neutron flux in theory.Set about from the geometry of beam-shaping body below, evaluate the geometry impact for epithermal neutron flux of different beam-shaping body.
As shown in Figure 7, it illustrates the geometry of beam-shaping body in the 4th embodiment, this beam-shaping body 40 includes beam entrance 41, target 42, it is adjacent to the slow body 43 of target 42, it is enclosed in the reflector 44 outside slow body 43, the thermal neutron absorber 45 adjacent with slow body 43, it is arranged on the radiation shield 46 in beam-shaping body 40 and beam outlet 47, target 42 and the proton beam generation nuclear reaction from beam entrance 41 incidence are to produce neutron, slow body 43 by the neutron degradation that produces from target 42 to epithermal neutron energy district, the neutron that reflector 44 will deviate from leads back to improve epithermal neutron intensity of beam, slow body 43 is arranged to bar shape, preferably, it is arranged to cylindrical shape, thermal neutron absorber 45 is used for when absorbing thermal neutron to avoid treating to cause multiple dose with shallow-layer normal structure, radiation shield 46 is used for shielding the neutron of seepage and photon to reduce the normal tissue dose in non-irradiated district, export at thermal neutron absorber 45 and beam and be provided with air duct 48 between 47.
As shown in Figure 8, it illustrates the geometry of beam-shaping body in the 5th embodiment, this beam-shaping body 50 includes beam entrance 51, target 52, it is adjacent to the slow body 53 of target 52, it is enclosed in the reflector 54 outside slow body 53, the thermal neutron absorber 55 adjacent with slow body 53, it is arranged on the radiation shield 56 in beam-shaping body 50 and beam outlet 57, target 52 and the proton beam generation nuclear reaction from beam entrance 51 incidence are to produce neutron, neutron forms neutron beam, neutron beam limits a major axis X 3, slow body 53 by the neutron degradation that produces from target 52 to epithermal neutron energy district, reflector 54 will deviate from the neutron of major axis X 3 and leads back to major axis X 3 to improve epithermal neutron intensity of beam, it is cone-shaped that slow body 53 is arranged to that two rightabouts adjoin each other, the left side of slow body 53 is bar shape, the right side of slow body 53 is taper into towards right side cone-shaped, both adjoin each other, thermal neutron absorber 25 is used for when absorbing thermal neutron to avoid treating to cause multiple dose with shallow-layer normal structure, radiation shield 26 is used for shielding the neutron of seepage and photon to reduce the normal tissue dose in non-irradiated district.
As one preferably, target 52 in 5th embodiment, slow body 53, reflector 54, thermal neutron absorber 55 can be identical with first embodiment with radiation shield 56, and radiation shield 56 therein includes the photon shielding 561 being made up of plumbous (Pb) and the neutron shield 562 being made up of polyethylene (PE), this neutron shield 562 can be arranged on beam and export 57 places.Export at thermal neutron absorber 55 and beam and be provided with air duct 58 between 57.Prosthese B3 is arranged on distance beam outlet 57 about 1cm place.
Adopt MCNP software that the simulation of the cylinder+cone in the slow body of the cylinder in the slow body of bicone, the 4th embodiment in the second embodiment and the 5th embodiment is calculated below:
Wherein, as following table four illustrates beam quality factor performance in these three embodiment in air:
Table four: beam quality factor in air
Wherein, as following table five illustrates the performance in the present these three embodiment of dose form:
Table five: dosage shows
| Dosage shows | Cylinder | Cylinder+cone | Bicone |
| Effective therapeutic depth | 11.8 | 10.9 | 10.9 |
| Effective therapeutic depth close rate | 2.95 | 4.28 | 4.47 |
| Dose therapeutically effective ratio | 5.52 | 5.66 | 5.66 |
Wherein, as following table six illustrates the parameter of assessment neutron beam dosage performance quality simulation value in these three embodiment:
Table six: the parameter that assessment neutron beam dosage performance is good and bad
| Parameter | Cylinder | Cylinder+cone | Bicone |
| Irradiation time (10mA) | 40.7 | 26.1 | 25.3 |
| 30.0RBE-Gy the degree of depth can be treated | 8.4 | 7.6 | 7.7 |
| Tumor maximal dose | 70.9 | 67.4 | 68.5 |
| Normal cerebral tissue's maximal dose | 12.0 | 11.2 | 11.3 |
| Skin maximal dose | 11.0 | 11.0 | 11.0 |
Note: be appreciated that from three above-mentioned tables: slow body is arranged at least one is cone-shaped, the treatment benefit of its neutron beam is better.
Fig. 9 show the application sixth embodiment, beam-shaping body 60 includes beam entrance 61, target 62, it is adjacent to the slow body 63 of target 62, it is enclosed in the reflector 64 outside slow body 63, the thermal neutron absorber 65 adjacent with slow body 63, it is arranged on the radiation shield 66 in beam-shaping body 60 and beam outlet 67, target 62 and the proton beam generation nuclear reaction from beam entrance 61 incidence are to produce neutron, neutron forms neutron beam, neutron beam limits a major axis X 6, slow body 63 by the neutron degradation that produces from target 62 to epithermal neutron energy district, reflector 64 will deviate from the neutron of major axis X 6 and leads back to major axis X 6 to improve epithermal neutron intensity of beam, it is provided with clearance channel 68 between slow body 63 and reflector 64, it is provided with air duct 69 between thermal neutron absorber 65 and beam outlet 67.This embodiment is the improvement to the 3rd embodiment, and concrete improvement is in that, slow body 63 is set to be rightabout adjoin each other cone-shaped, this slow body 63 has main part 631 and is enclosed in the supplementary portion 632 of main part 632 periphery.Main part 631 includes trunk portion 634 and is positioned at trunk portion 633 two ends and adjacent with trunk portion 633 two cone portion 634, supplementary portion 632 be coated on the periphery of trunk portion 633 and be connected with two cone portion 634 and make slow body 63 be formed that rightabout adjoins each other is cone-shaped.
Figure 10 is the 7th kind of embodiment of the application, beam-shaping body 70 includes beam entrance 71, target 72, it is adjacent to the slow body 73 of target 72, it is enclosed in the reflector 74 outside slow body 73, the thermal neutron absorber 75 adjacent with slow body 73, it is arranged on the radiation shield 76 in beam-shaping body 70 and beam outlet 77, target 72 and the proton beam generation nuclear reaction from beam entrance 71 incidence are to produce neutron, neutron forms neutron beam, neutron beam limits a major axis X 7, slow body 73 by the neutron degradation that produces from target 72 to epithermal neutron energy district, reflector 74 will deviate from the neutron of major axis X 7 and leads back to major axis X 7 to improve epithermal neutron intensity of beam, it is provided with air duct 78 between thermal neutron absorber 75 and beam outlet 77.The something in common of this embodiment and sixth embodiment is in that the left side of slow body 73 is all that the main part 731 formed by cone portion 734 and trunk portion 733 is collectively forming pyramidal structure with supplementary portion 732, it is different in that, in sixth embodiment, the right side of slow body 63 is cone-shaped reversely adjacent cone-shaped with left side, and in the 7th embodiment, the right side of slow body 73 is for being adjacent to the pyramidal bar shape in left side.That is the 7th embodiment is that slow body 73 is set to cone-shaped and that a bar shape is an adjacent structure.
In sixth embodiment and the 7th embodiment, the main part 631 (731) of described slow body 63 (73) is by D2O、AlF3、FluentalTM、CaF2、Li2CO3、MgF2And Al2O3In at least one make, supplementary portion 632 (732) is made up of any one in Zn, Mg, Al, Ti, La, Pb, Zr and Bi, and the material that supplementary portion 632 (732) uses is different from the material that main part 631 (731) uses.
Adopt MCNP software that main part in sixth embodiment and the 7th embodiment is adopted MgF below2Material, the simulation that supplementary portion is respectively adopted Zn, Mg, Al, Ti, La, Pb, Zr and Bi make calculates and (and adopts the MgF of material identical with main part with supplementary portion2As a comparison):
Wherein, as following table seven illustrates the parameter of assessment neutron beam dosage performance quality simulation value in both embodiments:
Table seven: the parameter that assessment neutron beam dosage performance is good and bad
As shown in Table 7, MgF is all adopted relative to main part and supplementary portion2The situation of material, uses MgF2Main part made by material, and when using Zn and Ti to make supplementary portion respectively, the treated degree of depth of neutron beam dosage can improve；Use MgF2Main part made by material, and when using La, Pb, Zr and Bi to make supplementary portion respectively, the irradiation time of neutron beam dosage can improve；And use MgF2Main part made by material, and when using Mg or Al to make supplementary portion, the irradiation time of neutron beam dosage all can be significantly improved in the degree of depth with treating.Accordingly, as one preferably, the main part 631 (731) of slow body uses MgF2Material is made, and supplementary portion 632 (732) uses Mg or Al to make.
And, Zn in employing table seven, Mg, Al, Ti, La, Pb, Zr and Bi material be easier to obtain, adopt these materials to make supplementary portion and can largely reduce the manufacturing cost of slow body.
" cylinder " described in the embodiment of the present application, " trunk portion " or " bar shape " refers to the structure being basically unchanged along the side of direction as shown to the overall trend of its outline of opposite side, a wherein contour line of outline can be line segment, corresponding contour line such as cylindrical shape, it can also be the circular arc close to line segment that curvature is bigger, the corresponding contour line of sphere body shape as bigger in curvature, the whole surface of outline can be rounding off, it can also be non-rounding off, a lot of projection and groove have been done in surface such as the sphere body shape bigger at cylindrical shape or curvature.
" cone ", " cone portion " or " cone-shaped " described in the embodiment of the present application refers to the structure tapered into along the side of direction as shown to the overall trend of its outline of opposite side, a wherein contour line of outline can be line segment, corresponding contour line such as cone shape, it can also be circular arc, corresponding contour line such as sphere body shape, the whole surface of outline can be rounding off, can also be non-rounding off, as done a lot of projection and groove on the surface of cone shape or sphere body shape.
The beam-shaping body for neutron capture treatment that the application discloses is not limited to the content described in above example and the structure represented by accompanying drawing.Change apparently, replacement or the amendment on the basis of the application, the material of wherein component, shape and position made, all within the scope that this application claims protection.
Claims (10)
1. the beam-shaping body for neutron capture treatment, it is characterized in that: described beam-shaping body includes beam entrance, target, it is adjacent to the slow body of described target, it is enclosed in described reflector external slowly, the thermal neutron absorber adjacent with described slow body, it is arranged on the radiation shield in described beam-shaping body and beam outlet, described target and the proton beam generation nuclear reaction incident from described beam entrance are to produce neutron, described neutron forms neutron beam, described neutron beam limits a main shaft, described slow body by the neutron degradation that produces from described target to epithermal neutron energy district, described slow body is arranged to comprise at least one pyramidal shape, described slow body has main part and is enclosed in the supplementary portion of main part periphery, the material of described supplementary portion is different from the material of main part, described reflector will deviate from the neutron of described main shaft and leads back to described main shaft to improve epithermal neutron intensity of beam, described thermal neutron absorber is used for when absorbing thermal neutron to avoid treating to cause multiple dose with shallow-layer normal structure, described radiation shield is used for shielding the neutron of seepage and photon to reduce the normal tissue dose in non-irradiated district.
2. the beam-shaping body for neutron capture treatment according to claim 1, it is characterized in that: described main part includes being adjacent to the cone portion of target and is adjacent to the trunk portion of cone portion, and described supplementary portion is coated on the external peripheral surface of trunk portion and is connected with cone portion thus being collectively forming described cone-shaped with cone portion.
3. the beam-shaping body for neutron capture treatment according to claim 1, it is characterised in that: described beam-shaping body is further used for the treatment of accelerator boron neutron capture.
4. the beam-shaping body for neutron capture treatment according to claim 3, it is characterized in that: proton beam is accelerated by the treatment of accelerator boron neutron capture by accelerator, described target is made of metal, described proton beam accelerates to the energy being enough to overcome target atom core coulomb repulsion, with described target generation nuclear reaction to produce neutron.
5. the beam-shaping body for neutron capture treatment according to claim 1, it is characterized in that: described beam-shaping physical ability by neutron slowly to epithermal neutron energy district, and reduce thermal neutron and fast neutron content, epithermal neutron energy district is between 0.5eV to 40keV, hanker subzone less than 0.5eV, fast-neutron range is more than 40keV, described slow body is big by having fast neutron action section, the material that epithermal neutron action section is little is made, described reflector is made up of the material having neutron reflection ability strong, described thermal neutron absorber is made up of the material big with thermal neutron action section.
6. the beam-shaping body for neutron capture treatment according to claim 4, it is characterised in that: described slow body is by D2O、AlF3、FluentalTM、CaF2、Li2CO3、MgF2And Al2O3In any one make, described reflector is made up of any one in Pb or Ni, described thermal neutron absorber by6Li makes, and is provided with air duct between described thermal neutron absorber and the outlet of described beam, and described radiation shield includes photon shielding and neutron shield.
7. the beam-shaping body for neutron capture treatment according to claim 4, it is characterised in that: described supplementary portion is made up of any one in Zn, Mg, Al, Ti, La, Pb, Zr and Bi.
8. the beam-shaping body for neutron capture treatment according to claim 1, it is characterised in that: described slow body is arranged to comprise a cone-shaped and shape with a described cone-shaped adjacent bar shape.
9. the beam-shaping body for neutron capture treatment according to claim 1, it is characterised in that: it is cone-shaped that described slow body is arranged to that two rightabouts adjoin each other.
10. the beam-shaping body for neutron capture treatment according to claim 9, it is characterized in that: described main part includes trunk portion and be positioned at trunk portion two ends the cone portion being connected with trunk portion two ends, described supplementary portion be coated on trunk portion periphery and be connected with two cone portion and make slow body be rightabout adjoin each other cone-shaped.
Priority Applications (7)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520955634.2U CN205339881U (en) | 2015-11-26 | 2015-11-26 | Beam shaper for neutron -capture therapy |
| EP16867832.4A EP3369457B1 (en) | 2015-11-26 | 2016-10-18 | Beam shaping body for neutron capture therapy |
| RU2019113041A RU2717363C1 (en) | 2015-11-26 | 2016-10-18 | Beam forming unit for neutron capture therapy |
| PCT/CN2016/102334 WO2017088606A1 (en) | 2015-11-26 | 2016-10-18 | Beam shaping body for neutron capture therapy |
| JP2018526537A JP6831844B2 (en) | 2015-11-26 | 2016-10-18 | Beam shaper for neutron capture therapy |
| TW105217415U TWM543059U (en) | 2015-11-26 | 2016-11-15 | Beam shaping assembly for neutron capture therapy |
| US15/970,001 US10639499B2 (en) | 2015-11-26 | 2018-05-03 | Beam shaping assembly for neutron capture therapy |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520955634.2U CN205339881U (en) | 2015-11-26 | 2015-11-26 | Beam shaper for neutron -capture therapy |
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| Publication Number | Publication Date |
|---|---|
| CN205339881U true CN205339881U (en) | 2016-06-29 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201520955634.2U Active CN205339881U (en) | 2015-11-26 | 2015-11-26 | Beam shaper for neutron -capture therapy |
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| CN (1) | CN205339881U (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
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| WO2017088606A1 (en) * | 2015-11-26 | 2017-06-01 | 南京中硼联康医疗科技有限公司 | Beam shaping body for neutron capture therapy |
| CN106798969A (en) * | 2015-11-26 | 2017-06-06 | 南京中硼联康医疗科技有限公司 | For the beam-shaping body of neutron capture treatment |
| CN108079443A (en) * | 2018-01-09 | 2018-05-29 | 广东东阳光药业有限公司 | A kind of beam-shaping body for neutron capture therapy |
| WO2018176686A1 (en) * | 2017-03-29 | 2018-10-04 | 南京中硼联康医疗科技有限公司 | Radiation irradiation system and positioning component for radiation irradiation system |
| CN108653935A (en) * | 2017-03-29 | 2018-10-16 | 南京中硼联康医疗科技有限公司 | Irradiation with radiation system and positioning component for irradiation with radiation system |
| CN108934120A (en) * | 2017-05-26 | 2018-12-04 | 南京中硼联康医疗科技有限公司 | Target and neutron capture treatment system for neutron beam generating apparatus |
| US11198023B2 (en) * | 2017-08-30 | 2021-12-14 | Neuboron Medtech Ltd. | Neutron capture therapy system |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| WO2017088606A1 (en) * | 2015-11-26 | 2017-06-01 | 南京中硼联康医疗科技有限公司 | Beam shaping body for neutron capture therapy |
| CN106798969A (en) * | 2015-11-26 | 2017-06-06 | 南京中硼联康医疗科技有限公司 | For the beam-shaping body of neutron capture treatment |
| US10639499B2 (en) | 2015-11-26 | 2020-05-05 | Neuboron Medtech Ltd. | Beam shaping assembly for neutron capture therapy |
| WO2018176686A1 (en) * | 2017-03-29 | 2018-10-04 | 南京中硼联康医疗科技有限公司 | Radiation irradiation system and positioning component for radiation irradiation system |
| CN108653935A (en) * | 2017-03-29 | 2018-10-16 | 南京中硼联康医疗科技有限公司 | Irradiation with radiation system and positioning component for irradiation with radiation system |
| EP3527261A4 (en) * | 2017-03-29 | 2019-11-13 | Neuboron Medtech Ltd. | Radiation irradiation system and positioning component for radiation irradiation system |
| US11338155B2 (en) | 2017-03-29 | 2022-05-24 | Neuboron Medtech Ltd. | Radiation irradiation system and positioning assembly for radiation irradiation system |
| CN108653935B (en) * | 2017-03-29 | 2023-06-02 | 南京中硼联康医疗科技有限公司 | Radiation irradiation system and positioning assembly for radiation irradiation system |
| CN108934120A (en) * | 2017-05-26 | 2018-12-04 | 南京中硼联康医疗科技有限公司 | Target and neutron capture treatment system for neutron beam generating apparatus |
| CN108934120B (en) * | 2017-05-26 | 2024-04-12 | 南京中硼联康医疗科技有限公司 | Target for neutron ray generating device and neutron capturing treatment system |
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