Low energy-high intensity proton or deuteron beam accelerating system

Abstract

To provide a low energy-high intensity proton or deuteron beam accelerating system.SOLUTION: The present invention relates to a cyclotron including first and second internal ion sources configured to form first and second beams of the same charged particles, respectively. The cyclotron is also configured to create a local asymmetry of an accelerating electric field and / or of a magnetic field so as to combine the first and second beams to form a combined beam and to drive the combined beam through a single extraction outlet. The present invention also relates to an accelerating system including N cyclotrons, of which M (M>0) are according to the present invention. The present invention also relates to an apparatus for treating a patient by BNCT including an accelerating system according to the present invention, a target configured to emit an epithermal beam of neutrons upon bombarding with a multi-combined beam of protons or deuterons, and a treatment area configured to hold a patient to be treated within a treatment zone.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to the field of cyclotrons for accelerating charged particles. In particular, the present invention relates to a cyclotron configured to extract a beam of charged particles of a given energy with an intensity value approximately twice that of conventional cyclotrons. The present invention also relates to a charged particle acceleration system combining two or more cyclotrons arranged in parallel to combine the respective beams, at least one of the cyclotrons, preferably all of the cyclotrons, according to the present invention. For example, an accelerated beam of protons or deuterons with low energy and high intensity is required to generate an epithermal neutron beam that can be used, for example, in boron neutron capture therapy (BNCT). [Background technology]

[0002] Charged particle accelerators can be used in many applications. For example, beams of charged particles can be used to treat cancer by killing tumor cells or to generate isotopes for medical imaging applications. For example, boron neutron capture therapy (BNCT) is a neutron-based technology that allows selective cancer treatment at the tumor cell level. It uses benign boron-10 ( 10 B) The biological targeting accuracy of targeted drugs combined with a neutron source. 10 The therapeutic dose is then delivered only to cells containing B. 10 Neutrons captured by B generate short-range alpha and lithium particles that directly induce double-strand DNA breaks in cancer cells, providing advantages over other conventional cancer treatments. Indeed, the path length of the particles is limited to approximately 10 μm, which corresponds to the diameter of the cell, so the destructive effect of this therapy is limited to cells containing boron.

[0003] The neutron source for boron neutron capture therapy can be a nuclear reactor or a charged particle accelerator. Accelerators have the potential to produce a neutron beam with better energy distribution than nuclear reactors, i.e., lower neutron energy and less widely distributed. Accelerators are also more compact than nuclear reactors and are more suitable for installation in hospitals.

[0004] Accelerators generate beams of charged particles, such as protons or deuterons, accelerated to a specified energy. The proton or deuteron beam can be directed toward a target material to initiate a nuclear reaction that results in a neutron beam with a specified energy and energy distribution useful for BNCT. Figure 7 provides some examples of target materials and types of charged particles, as well as the energy required to generate neutrons. The first symbol d or p in parentheses indicates the charged particle, and the second symbol n in parentheses indicates the beam formed by the nuclear reaction, where p = proton, d = deuteron, and n = neutron. For example, "Li(d,n)" indicates irradiating a lithium target with a deuteron beam to form neutrons. It can be seen that a relatively low-energy (<5.0 MeV) beam is generally sufficient to form a neutron beam, making it preferable to a high-energy neutron beam for forming an epithermal neutron beam, which is preferred for BNCT.

[0005] For example, to generate neutrons in a proton beam, lithium ( 7 Li) and beryllium ( 9 Two main types of targets are used: Lithium: p+ 7 Li→n+ 7 For the formation of Be-epithermal neutrons, a proton beam with an energy comprised between 1.9 and 5 MeV and an intensity comprised between 10 mA and 30 mA is required to provide an acceptable treatment duration. Beryllium: p+ 9 Be→n+ 9 B - requires a proton beam with an intensity of more than 10 mA at low energies and less than 2 mA at energies above 30 MeV, at energies below 40 MeV.

[0006] A similar reaction can be achieved with a beam of deuterons starting at a slightly lower energy, as shown in Figure 7, where the reaction with deuterons is represented by the dashed line. 13 C can also be targeted by a deuteron beam.

[0007] The systems developed so far have a significant footprint that is largely determined by the size / length of the accelerator itself. Even cyclotrons, which are generally known as a more compact solution than, for example, linear accelerators, must be very large, since even existing cyclotrons that generate 30 MeV proton beams deliver a maximum current that is generally comprised between 1 and about 3 mA, which is insufficient to produce enough epithermal neutrons without significantly prolonging the patient's irradiation.

[0008] To reduce the installation footprint and cost, it has been interesting to develop 2.5-5 MeV cyclotrons for use in BNCT instead of 30 MeV cyclotrons, as 30 MeV cyclotrons promote the formation of higher energy neutron beams that are undesirable for BNCT. The challenge at these low energy values ​​is providing intensities of 6-20 mA, when standard cyclotrons function at about 1-2 mA, and cyclotron alternatives are larger and more expensive.

[0009] (Patent Document 1) proposes the use of two ion particle sources, which can be used alternatively in case one of the sources fails, or simultaneously. When used simultaneously, the generated beam current can be doubled, but reaches two separate targets through two different extraction outlets. Therefore, regardless of whether the two sources are used alternatively or simultaneously, each target is irradiated by a beam of the same energy and intensity.

[0010] Similarly, U.S. Patent No. 6,269,949 describes a cyclotron with two internal ion sources that can be used alternatively or simultaneously. Unlike U.S. Patent No. 6,269,949 discussed above, U.S. Patent No. 6,269,949 does not explicitly state whether one target or two targets are irradiated when both internal ion sources are used simultaneously. However, the cyclotron is described as having two-fold rotational symmetry about the central vertical axis, thus requiring two diametrically opposed extraction outlets and therefore two different targets. This is also evident from the fact that the first and second internal ion sources are designed and positioned to prevent the extracted beam from one internal ion source from impinging on the other internal ion source. Thus, the two beams follow two separate, parallel paths without merging into a single beam. Again, therefore, regardless of whether the two sources are used alternatively or simultaneously, each target is irradiated by a beam of the same energy and intensity.

[0011] US Patent No. 5,949,999 describes a cyclotron with two internal ion sources positioned side-by-side at different orientations to emit ions along different directions, resulting in the extraction exits of the two beams being offset.

[0012] Patent document 4 describes a particle accelerator comprising at least one first cyclotron and a second cyclotron surrounding the first cyclotron and configured to accelerate particles extracted from the first cyclotron. A proton beam with an energy higher than 10 MeV and an intensity of 10 mA can be obtained.

[0013] (Patent Document 5) describes a cyclotron and a target system within the cyclotron. Accelerated particles first strike a target, transferring some of their energy to the target and driving a nuclear reaction. As the particles accelerate on their next trajectory, they repeatedly strike the target. This process of continuous impact results in a buildup of beam current striking the target, which proportionally increases the rate of the nuclear reaction. Because the beam, after striking the target, is recycled to regain the energy lost to the target, the authors called this integrated unit a "Recyclotron."

[0014] Patent Document 6 describes a charged particle acceleration system for generating neutron beams for neutron capture therapy (NCT). The beams of N cyclotrons are combined to generate a low-energy, high-intensity beam. If all N cyclotrons are identical, the resulting combined beam has the same energy as each individual beam, but is N times more intense than each individual beam.

[0015] US Pat. No. 5,629,493 describes a system comprising two electron accelerators of the Rhodotron® type, which irradiate a target simultaneously from two different directions using two different electron beamlines. [Prior art documents] [Patent documents]

[0016] [Patent Document 1] European Patent Application Publication No. 3024306 [Patent Document 2] European Patent Application Publication No. 2196073 [Patent Document 3] Korean Patent Publication No. 20200095277 [Patent Document 4] International Publication No. 03092339 Brochure [Patent Document 5] U.S. Patent No. 6,130,926 [Patent Document 6] Korean Patent No. 102178632 [Patent Document 7] International Publication No. 2022040219 Brochure Summary of the Invention [Problem to be solved by the invention]

[0017] The present invention proposes a simple and compact cyclotron configured to generate a combined beam of charged particles of low energy (about 1-5 MeV) or medium energy (e.g., about 75 MeV) and high intensity (about 2-10 mA). By combining the combined beam of the cyclotron of the present invention with the beam of another cyclotron, preferably with the combined beam of another cyclotron according to the present invention, a low energy beam with high intensity can be obtained. These and other advantages are described below. [Means for solving the problem]

[0018] The present invention provides a cyclotron centered on the Z1 axis for generating a combined beam of charged particles, comprising: Protons, deuterons, hydrogen molecular ions (H2 + ), and He ions (He 2+ or He + a first internal ion source configured to generate charged particles selected from among protons and deuterons and introduce the charged particles through a first slit into the cyclotron to form a first beam of charged particles, the charged particles preferably being selected from among protons and deuterons; a second internal ion source configured to generate the same charged particles as the first internal ion source and to introduce the charged particles through a second slit into the cyclotron simultaneously with the first internal ion source to form a second beam of charged particles, the second internal ion source being positioned on an opposite side of the Z1 axis from the first internal ion source; and a dee electrode assembly and a counter dee electrode assembly separated from each other by a gap; a generator configured to apply an AC high voltage to the dee electrode assembly to generate an accelerating electric field in the gap to accelerate the first and second beams of charged particles; a magnetic field system configured to generate a magnetic field parallel to the Z1 axis and to guide the first and second beams of charged particles along first and second spiral trajectories, respectively, through the accelerating electric field in the gap, thereby accelerating the first and second beams of charged particles upon each passage through the accelerating electric field in the gap; The present invention relates to a cyclotron comprising:

[0019] The cyclotron of the present invention is configured to create a local asymmetry in the accelerating electric and / or magnetic fields configured to deflect the first and / or second trajectories so as to drive the combined beam formed by the first and second beams along the first and second trajectories through a single extraction outlet. The directions of the first and second beams forming the combined beam at the level of the extraction outlet form an angle (2) of less than 15°, preferably less than 10°, and more preferably less than 5° in a plane perpendicular to the Z1 axis, and more preferably the two directions are substantially parallel at an angle of 2°±1°. The angle (2) must allow the two beams to intersect a given target plane within a combined spot of a given diameter, the target plane being located at a given distance from the extraction outlet along the Z axis.

[0020] In one embodiment, the magnetic field system includes a pair of coils powered by a generator and surrounding a volume of ferromagnetic material having a thickness measured along the Z1 axis. The local asymmetry in the magnetic field that deflects the first trajectory and / or the second trajectory is created by a local variation in the thickness and / or shape of the ferromagnetic material. Alternatively, or additionally, the local asymmetry in the magnetic field can be created by one or more local magnetic sources selected from among the coils and permanent magnets.

[0021] In alternative or additional embodiments, the local asymmetry in the accelerating electric field can be created by a local difference in the gap geometry between the dee electrode assembly and the counter-dee electrode assembly and / or by asymmetric geometry and / or positioning of the first internal ion source and the second internal ion source relative to the Z1 axis. For example, the asymmetric positioning of the first source and the second source relative to the Z1 axis can be created at least in part by offsetting the position of the second internal ion source from axial symmetry with the position of the first internal ion source relative to the Z1 axis. The offset can be either circumferential with respect to the Z1 axis, radial with respect to the Z1 axis, or a combination of radial and circumferential with respect to the Z1 axis.

[0022] The cyclotron of the present invention can be configured to emit a combined beam at a single extraction outlet having an energy (E1) of less than 75 MeV per nucleon (i.e., E1≦75 MeV / A), preferably less than 5 MeV per nucleon (i.e., E1≦5 MeV / A). The current intensity (i) can be at least 1 mA (i.e., i≧1 mA), preferably at least 2 mA (i.e., i≧2 mA), preferably at least 5 mA (i.e., i≧5 mA), more preferably at least 10 mA (i.e., i≧10 mA).

[0023] The present invention also preferably uses protons, deuterons, hydrogen molecular ions (H + ), and He ions (He 2+ or He +The present invention relates to an acceleration system for generating a low-energy, high-intensity beam of charged particles selected from among Zi, Zj ...

[0024] The N individual beams (i.e., the M combined beams of the M cyclotrons of the present invention and the (NM) first beams of the (NM) conventional cyclotrons) form a multiple combined beam and are contained within a cone with an aperture 2θ of 70° or less (i.e., 2θ≦70°), preferably 50° or less (i.e., 2θ≦50°), and more preferably 25° or less (i.e., 2θ≦25°). The N individual beams form N individual spots of given diameters on a target plane adjacent to the target, perpendicular to the axis (X) of the cone, and located at a predetermined position. The N individual spots are inscribed in an ellipse of area (A) less than a predetermined maximum area (Am) that defines the multiple combined spot. Area (A) is defined as the area where 90% of the incident beam particles strike the target plane, and the maximum area (Am) is preferably at least 10 cm. 2 , more preferably at least 50 cm 2 is.

[0025] The multiple combined beams have an energy (Ec) at the multiple combined spot of less than 75 MeV per nucleon (i.e., Ec≦75 MeV / A), preferably less than 5 MeV per nucleon (i.e., Ec≦5 MeV / A). The multiple combined beams have a current intensity (Ic) of at least 2 mA (i.e., Ic≧2 mA), preferably at least 4 mA (i.e., Ic≧4 mA), preferably at least 10 mA (i.e., Ic≧10 mA), more preferably at least 20 mA (i.e., Ic≧20 mA).

[0026] In one embodiment, the acceleration system comprises M1 cyclotrons among the N cyclotrons (2≦M1≦N, preferably M1=N). The M1 cyclotrons may be positioned side by side in the same plane perpendicular to Zi axes that are parallel to each other. Alternatively, the M1 cyclotrons may be positioned on top of each other, preferably tilted relative to each other, the Zi axes of two adjacent cyclotrons preferably forming an angle of less than 30°. The M1 cyclotrons are preferably positioned and configured to generate magnetic fields with rotational symmetry of order M1 between each other.

[0027] In one embodiment, the acceleration system includes M2 cyclotrons (2≦M2≦N, preferably M2=N) among the N cyclotrons. The M2 cyclotrons share common components in one or more of the following ways: In one embodiment, each of the M2 cyclotrons includes a dee electrode assembly and a counter-dee electrode assembly, and the acceleration system includes a single RF generator configured to apply an AC high voltage to the dee electrode assemblies of the M2 cyclotrons to generate an accelerating electric field. Alternatively, or additionally, each of the M2 cyclotrons includes a coil configured to generate a magnetic field (B) passing perpendicular to the plane (X, Y), and the acceleration system includes a single magnetic field generator configured to apply current to the coils of the M2 cyclotrons to generate the magnetic field (B). Alternatively, or additionally, the M2 cyclotrons share a common yoke that defines a single magnetic flux circuit spanning all of the M2 cyclotrons.

[0028] The acceleration system preferably includes a scanner configured to scan multiple coupled spots over a predetermined area of ​​the target plane, the predetermined area being at least 30 cm. 2 , preferably at least 100 cm 2 It can be said that:

[0029] The acceleration system can include a target adjacent to the target plane made of a material configured to emit neutrons or specific isotopes when a low-energy, high-intensity beam of protons or deuterons passes through the multiply-coupled spot. In an alternative embodiment, the target plane can be upstream of and adjacent to an entrance of a second acceleration system including at least one acceleration device that increases the energy of the multiply-coupled beam.

[0030] The present invention also relates to an apparatus for administering treatment by boron neutron capture therapy (BNCT). The apparatus comprises a target, a cyclotron or acceleration system according to the present invention as described above, a beam shaping assembly, and a treatment area. The target is made of a material configured to emit neutrons when a beam of accelerated protons or deuterons passes through it. The material can be selected from beryllium (Be) and lithium (Li). The cyclotron or acceleration system is configured to emit a (multiple) combined beam of protons or deuterons. The beam shaping assembly is configured to shape an epithermal neutron beam and to direct the epithermal neutron beam thus formed towards a treatment zone. The treatment area is configured to receive and support a portion of a patient to be treated with the epithermal neutron beam within the treatment zone.

[0031] The beam shaping assembly preferably comprises a collimator with the exit of the shaping assembly preferably located at a distance of less than 400 mm, preferably less than 200 mm, more preferably less than 125 mm from the treatment zone.

[0032] The device of the present invention is configured to move the epithermal beam relative to the treatment zone. This can be achieved in various ways, which can be combined with each other. For example, the epithermal beam can be moved relative to the treatment zone by moving the treatment zone and the patient relative to the epithermal beam, which remains fixed in position. This can also be achieved by moving the epithermal beam relative to the treatment zone, which remains fixed in position. In this case, the device includes a rotation mechanism configured to rotate and guide both the combined beam and the epithermal beam. Of course, the epithermal beam and the treatment zone can be moved relative to each other by moving both the treatment zone and the epithermal beam relative to each other as described above.

[0033] These and further aspects of the invention will now be described in more detail, by way of example, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0034] [Figure 1] Figure 1a shows a combined beam formed by two parallel individual beams. Figure 1b shows a combined beam formed by two perfectly coincident individual beams. Figure 1c shows a combined beam formed by two converging individual beams intersecting the target plane upstream of the focus. Figure 1d shows a combined beam formed by two converging individual beams intersecting the target plane downstream of the focus. Figure 1e shows a combined beam formed by two diverging individual beams. Figure 1f shows a multiple combined beam formed by several combined beams and the first beam from the corresponding cyclotron. [Figure 2] FIG. 2 shows a top view of a cyclotron according to the present invention, along with the first and last turns of the path in which the beams emitted from the first internal ion source and the second internal ion source combine to form a combined beam that is extracted from a single extraction outlet. [Figure 3] Figure 3a shows a top view of a cyclotron according to the present invention, showing the positions of the first and second internal ion sources relative to each other and relative to the dee and counter-dee. Figure 3b shows a system formed by two cyclotrons of the type illustrated in Figure 3a arranged in parallel to combine their respective combined beams to form a multiple combined beam of the type illustrated in Figure lc. Figure 3c shows a system formed by three cyclotrons of the type illustrated in Figure 3a arranged in parallel to combine their respective combined beams to form a multiple combined beam of the type illustrated in Figure lc. [Figure 4]Figure 4a illustrates various local asymmetries of the acceleration electric field created by the asymmetric geometry and / or arrangement of the first and second internal ion sources relative to the Z1 axis. Figure 4b illustrates various local asymmetries of the acceleration electric field created by the asymmetric geometry and / or arrangement of the first and second internal ion sources relative to the Z1 axis. Figure 4c illustrates various local asymmetries of the acceleration electric field created by the asymmetric geometry and / or arrangement of the first and second internal ion sources relative to the Z1 axis. Figure 4d illustrates various local asymmetries of the acceleration electric field created by the asymmetric geometry and / or arrangement of the first and second internal ion sources relative to the Z1 axis. [Figure 5] Figure 5a shows two cyclotrons arranged side by side with magnetic flux circulating from one cyclotron to the other via upper and lower yokes, while Figure 5b shows two cyclotrons arranged side by side with independent magnetic flux circuits. [Figure 6] Figure 6a shows two cyclotrons placed on top of each other with magnetic flux circulating from one cyclotron to the other through a shared internal pole, while Figure 6b shows two cyclotrons placed on top of each other at an angle with independent magnetic flux circuits. [Figure 7] Figure 7 shows a graph of the neutron yield as a function of the energy of the beam striking the target material (Li, C, Be), where the type of particle forming the beam is defined by the first letter in brackets: d = deuterons and p = protons, and the letter n in the second position indicates that neutrons are formed. [Figure 8] FIG. 8 shows an apparatus for administering boron neutron capture therapy (BNCT) treatment in accordance with the present invention. [Figure 9]Figure 9a shows an embodiment for moving the target orientation relative to the neutron beam, where the treatment area is configured to move relative to the neutron beam by rotation about the Z and Y axes and translation along the Z and Y axes. Figure 9b shows an embodiment for moving the target orientation relative to the neutron beam, where the acceleration system and beam shaping assembly are configured to rotate about the Y axis relative to the treatment area. Figure 9c shows an embodiment for moving the target orientation relative to the neutron beam, where the acceleration system and beam shaping assembly are configured to rotate about the X axis relative to the treatment area. DETAILED DESCRIPTION OF THE INVENTION

[0035] As shown in Figures 2 and 3a, the present invention relates to a cyclotron (10.1) centered on the Z1 axis for generating a combined beam (1c1) of charged particles. The cyclotron comprises a first internal ion source (12.11) and a second internal ion source (12.12), a dee electrode assembly (5D) and a counter-dee electrode assembly (5C), a generator (7RF) configured to apply an AC high voltage between the dee electrode assembly (5D) and the counter-dee (5C), and magnetic field generators (7B, 7C) configured to generate a magnetic field parallel to the Z1 axis.

[0036] The first internal ion source (12.11) is configured to generate charged particles and introduce them into the cyclotron through a first slit to form a first beam of charged particles (1.11). The second internal ion source (12.12) is configured to generate the same charged particles as the first internal ion source (12.11) and introduce them into the cyclotron through a second slit simultaneously with the first internal ion source (12.11) to form a second beam of charged particles (1.12). The second internal ion source (12.12) is positioned on the opposite side of the first internal ion source (12.11) from the first internal ion source (12.11) with respect to the Z1 axis (i.e., the angle formed between the first and second internal ion sources at the Z1 axis is at least 90°, preferably 180°±20°, more preferably 180°±10°, and most preferably 180°±5°).

[0037] The dee electrode assembly (5D) and the counter dee electrode assembly (5C) are separated from each other by a gap (5G). The generator (7RF) is configured to apply an AC high voltage to the dee electrode assembly (5D) to generate an accelerating electric field within the gap (5G) to accelerate the first beam (1.11) and the second beam (1.12) of charged particles. The dee electrode assembly (5D) and the counter dee electrode assembly (5C) can have different geometries known in the art. In FIG. 3a, the dee electrode assembly (5D) and the counter dee electrode assembly (5C) comprise two dee electrodes positioned symmetrically with respect to the Z1 axis. Each dee electrode is coupled to two counter dee electrodes separated by a cap (5G). The counter dee electrodes and the first internal ion source (12.11) and the second internal ion source (12.12) are grounded to ground potential. Other geometries known in the art can alternatively be used in the present invention.

[0038] The magnetic field systems (7B, 7C) are configured to generate a magnetic field parallel to the Z1 axis and guide the first beam (1.11) and the second beam (1.12) of charged particles along first and second spiral trajectories, respectively, passing through the accelerating electric field in the gap (5G) through the Dee electrode assembly (5D) and the counter Dee electrode assembly (5C), accelerating the first beam and the second beam of charged particles each time they pass through the accelerating electric field in the gap (5G).

[0039] Unless specific measures are taken to prevent this, the first beam (1.11) and the second beam (1.12) will follow the first and second trajectories without merging and will exit the cyclotron through separate extraction outlets (13). The gist of the invention is that the cyclotron (10.1) is configured to create a local asymmetry (7L) of the accelerating electric and / or magnetic fields that is configured to converge the first beam (1.11) and the second beam (1.12) together to form a combined beam (1c1) and drive it through a single extraction outlet (13). The combined beam (1c1) is formed by converging the first and second trajectories of the first beam (1.11) and the second beam (1.12), the respective directions of which at the level of the extraction outlet (13) are either substantially parallel (see Figure 1a), or even coincident (see Figure 1b), or converge at an angle of less than 15°, preferably less than 10°, more preferably less than 5° towards a given point located outside the cyclotron (Figure 1c).

[0040] The cyclotron (10.1) of the present invention is a cyclotron for generating protons, deuterons, and hydrogen molecular ions (H2 + ), and He ions (He 2+ or He + ) can be configured to accelerate selected charged particles within the neutron beam. For example, when generating neutron beams for use in boron neutron capture therapy (BNCT), the charged particles are preferably protons or deuterons.

[0041] Electric and / or magnetic field asymmetry As discussed in the Background section, two beams of the same charged particles introduced into the cyclotron (10.1) through two separate internal ion sources (12.11, 12.12) and subjected to identical electric and magnetic fields must follow two separate trajectories that are destined to remain separate and substantially parallel throughout their progression within the cyclotron (10.1) until they reach their corresponding extraction outlets (13).

[0042] The objective of the present invention is to form a single combined beam (1c1) by independently modifying the two separate trajectories and extracting the combined beam (1c1) through a single extraction outlet (13). In the present invention, this is achieved by creating local asymmetries in the accelerating electric and / or magnetic fields configured to modify the first and / or second trajectories.

[0043] Some examples of asymmetries are discussed below, depending on whether they primarily affect the magnetic or electric fields. The following embodiments can be implemented as an alternative or in addition:

[0044] Magnetic field asymmetry (7L) In one embodiment of the present invention, the coupling of the two trajectories to form the combined beam (1c1) can be driven by a magnetic field asymmetry (7L). For example, the magnetic field system (7B, 7C) can comprise a pair of coils powered by a generator (7B) and surrounding a volume of ferromagnetic material having a thickness measured along the Z1 axis. The local magnetic field asymmetry (7L) can be created by a local variation in the thickness and / or shape of the ferromagnetic material located in a specific segment of the first beam (1.11) and / or the second beam (1.12). Alternatively, or additionally, as shown in FIG. 3a, the magnetic field asymmetry (7L) can be created by one or more local magnetic sources (7M) selected from coils and permanent magnets positioned at appropriate locations, which create a local magnetic field asymmetry (7L) that deflects the first and / or second trajectories from the "undeflected" trajectories that would result in the absence of the local magnetic source (7M). The local magnetic field asymmetry (7L) created by a coil can be controlled not only by proper design of the coil, but also by controlling the power supplied to the coil, whereas the local magnetic field asymmetry created by a permanent magnet is controlled only by the design of the permanent magnet and cannot be changed at will.

[0045] Electric field asymmetry (7L) In one embodiment of the present invention, the combination of the two trajectories to form the combined beam (1c1) can be driven by an electric field asymmetry (7L). For example, the electric field asymmetry (7L) can be created by a local difference in the gap geometry between the dee electrode assembly (5D) and the counter-dee electrode assembly (5C). Alternatively, or concomitantly, the electric field asymmetry (7L) can be created by an asymmetric geometry and / or positioning of the first internal ion source (12.11) and the second internal ion source (12.12) relative to the Z1 axis and the gap (5G).

[0046] As illustrated in Figures 4a-4d, the asymmetric geometry and / or positioning of the first internal ion source (12.11) and the second internal ion source (12.12) relative to the Zl axis can be created at least in part by offsetting the position of the second internal ion source (12.12) from axial symmetry with the position of the first internal ion source (12.11) relative to the Zl axis. The offset can be obtained in a variety of ways.

[0047] In the embodiment illustrated in Figure 4b, the offset can be circumferential to the Z1 axis by having the first internal ion source (12.11) and the second internal ion source (12.12) located at the same distance from the Z1 axis but not aligned with the Z1 axis.

[0048] In the embodiment illustrated in Figure 4C, the offset can be radial to the Z1 axis by having the first internal ion source (12.11) at a different distance relative to the Z1 axis than the second internal ion source (12.12) so that the two internal ion sources (12.11, 12.12) are aligned with the Z1 axis.

[0049] As shown in Figure 4d, the offset can be a combination of both radial and circumferential offsets relative to the Zl axis. Figure 4a illustrates an embodiment in which the first internal ion source (12.11) and the second internal ion source (12.12) are positioned symmetrically relative to the Zl axis, but have different geometries to locally perturb the electric field. Of course, the first and second internal ion sources can combine different geometries and positional offsets relative to the Zl axis.

[0050] In contrast to a cyclotron with two internal sources for extracting two beams of identical characteristics through two separate extraction outlets, in the present invention, the first and second beams do not necessarily have to be identical in terms of energy and current intensity, since they combine to form the combined beam (1c1). This means that the second beam (1.12) can cross the gap (5G) fewer times than the first beam (1.11) to allow them to combine to form the combined beam (1c1). In such a case, the second beam (1.12) will have a lower energy than the first beam (1.11) when emitted separately from the corresponding first and second internal ion sources. In general, the two beams will differ from each other by half a full circumference, so they can be approximated as having substantially the same energy at the extraction outlet (13).

[0051] Combined beam (1c1) The combined beam (1c1) is formed by combining the first and second trajectories of the first and second beams (1.11 and 1.12). Ideally, when combined, the first and second trajectories are parallel to each other, as illustrated in FIG. 1a, and preferably coincident (i.e., overlapping), as illustrated in FIG. 1b. However, it is not necessary to control the first and second trajectories to be perfectly parallel, or even coincident. As illustrated in FIGS. 1c and 1d, the first and second beams (1.11 and 1.12) forming the combined beam (1c1) can propagate by converging toward a focal point and intersecting the target surface (6p) within a combination spot (1s1) of a given dimension either upstream or downstream of the focal point. As illustrated in FIG. 1e, the first and second beams may also diverge, provided they intersect a combination spot (1s1) of a given diameter. The angle (2α) between the first and second beams has an absolute value of less than 15° (i.e., 2α≦15°), and may be less than 10° (i.e., 2α≦10°), more preferably less than 5° (i.e., 2α≦5°), or even 2α=2°±1°. The first and second beams are configured to impinge on a given target plane within a coupling spot (1s1), as shown in FIGS. 1a-1c. At the single extraction outlet (13), the first and second beams are close to each other, preferably separated by a distance of less than 30 mm, more preferably less than 20 mm, or even less than 10 mm. At the extraction exit, the first beam (1.11) and the second beam (1.12) may be parallel or coincident (see Figures 1a and 1b), convergent with the target plane (6p) located upstream or downstream of the focus, as shown in Figures 1c and 1d, respectively, or slightly divergent, as shown in Figure 1e, as long as they both intersect the target surface (6p) within the coupling spot (1s1).

[0052] At the single extraction outlet (13), the combined beam (1c1) of the cyclotron of the present invention (with a first internal ion source (12.11) and a second internal ion source (12.12)) has approximately the same energy (E1) and approximately twice the intensity of the individual beams of a state-of-the-art cyclotron with a single internal ion source. For example, the combined beam (1c1) can have an energy (E1) of less than 75 MeV per nucleon (i.e., E1≦75 MeV / A), preferably less than 10 MeV per nucleon (i.e., E1≦10 MeV / A), more preferably less than 5 MeV per nucleon (i.e., E1≦5 MeV / A), and more preferably less than 3.5 MeV per nucleon (i.e., E1≦3.5 MeV / A). The combined beam (1c1) can have a maximum current intensity (i) of at least 1 mA (i.e., i≧1 mA), preferably at least 2 mA (i.e., i≧2 mA), more preferably at least 3 mA (i.e., i≧3 mA), more preferably at least 4 mA (i≧4 mA), more preferably at least 5 mA (i≧5 mA), more preferably at least 7 mA (i≧7 mA), more preferably at least 10 mA (i≧10 mA). For protons, the combined beam (1c1) can have a power E1×i at a single extraction outlet (13) greater than 10 MeV·mA, preferably greater than 20 MeV·mA.

[0053] Acceleration System The present application also preferably uses protons, deuterons, hydrogen molecular ions (H + ), and He ions (He 2+ or He +The present invention relates to an acceleration system for generating a low-energy, high-intensity beam of charged particles selected from the group consisting of 10.i, 12.i, 13.i, 14.i, 15.i, 16.i, 17.i, 18.i, 19.i, 20.i, 21.i, 22.i, 23.i, 24.i, 25.i, 26.i, 27.i, 28.i, 29.i, 30.i, 31.i, 32.i, 33.i, 34.i, 35.i, 36.i, 37.i, 38.i, 39.i, 40.i, 41.i, 42.i, 43.i, 44.i, 45.i, 46.i, 47.i, 48.i, 49.i, 50.i, 51.i, 52.i, 53.i, 54.i, 55.i, 56.i, 57.i, 58.i, 59.i, 60.i, 61.i, 62.i, 63.i, 64.i, 65.i, 66.i, 67.i, 68.i, 69.i, 70.i, 71.i, 72.i, 73.i, 74.i, 75.i, 76.i, 77.i, 78.i, 79.i, 80.i, 81.i, 82.i, 83.i, 84.i, 85.i, 86.i, 87.i, 88.i, 89.i, 90.i,

[0054] According to the invention, M cyclotrons (10.i) (M between 1 and N) according to the invention as discussed above are equipped with a first internal ion source (12.i1) and a second internal ion source (12.i2) and are configured to extract combined beams (1ci) (i = 1 to M). In total, the acceleration system is capable of extracting N individual beams composed of M combined beams (1ci = 1c1 to 1cM) extracted from the M cyclotrons according to the invention and (NM) first beams (1.i1) extracted from (NM) conventional cyclotrons equipped with a single internal ion source (12.i1).

[0055] The N individual beams (1ci, 1.i) are combined to form a single multiple combined beam (1c). As shown in FIG. 1d, the N individual beams (1ci, 1.i) forming the multiple combined beam (1c) are contained within a cone of aperture (2θ) of 70° or less (i.e., 2θ≦70°), preferably 50° or less (i.e., 2θ≦50°), and more preferably 25° or less (i.e., 2θ≦25°). The N individual beams are formed by n=ni1+ni2 first and second beams (1.ij) accelerated by N cyclotrons (10.i). All cyclotrons emit first beams (1.i1), so the number of first beams (1i.1) is ni1=N, and only the cyclotron according to the present invention emits second beams (1.i2), so the number of second beams (1i.2) is ni2=M. Therefore, the number n of the first beams (1i1) and second beams (1i2) participating in the formation of the multiple combined beam (1c) is n=N+M, which is between (N+1) when n12=M=1 for a cyclotron according to the invention, and 2N when n12=M=N for all cyclotrons of the acceleration system according to the invention, i.e., equipped with a first internal ion source (12.i1) and a second internal ion source (12.i2).

[0056] The N individual beams (1ci, 1.i) form N individual spots (1si) of a given diameter on a target plane (6p) located adjacent to the target (6), perpendicular to the axis (X) of the cone and at a predetermined position. The N individual spots (1si) are inscribed in an ellipse that defines the multiple combined spot (1s). The multiple combined spot (1s) has an area (A) that is less than a predetermined maximum area (Am). The area (A) is defined as the area where 90% of the incident beam particles strike the target plane (6p). The maximum area (Am) is preferably at least 10 cm 2 , more preferably at least 50 cm 2 is.

[0057] For example, as shown in Figures 3b and 3c, the system comprises M = N = 2 and 3 cyclotrons, respectively, and corresponding combined beams (1c1 to 1cN) formed by n = 2N = 4 and 6 first and second beams (1.i1, 1.i2, i = 1 to N), respectively. The N combined beams (1c1 to 1cN) are combined to form a single multiple combined beam (1c) and are focused to a multiple combined spot (1s) at the level of the target plane (6p).

[0058] When n first and second beams (1.1j to 1.Nj, j = 1 or 2) all have the same energy Eij and the same intensity Iij, the multiple combined beam (1c) has a combined energy Ec ≈ Eij and a combined intensity Ic ≈ n × Iij. The multiple coupled beams (1c) emitted by the acceleration system of the present invention form multiple coupled beams (1c) at the multiple coupled spots (1s) with a combined energy (Ec) of less than 75 MeV per nucleon (i.e., Ec≦75 MeV / A), preferably less than 10 MeV per nucleon (i.e., Ec≦10 MeV / A), more preferably less than 5 MeV per nucleon (i.e., Ec≦5 MeV / A), and have a maximum combined current intensity (Ic) of at least 2 mA (i.e., Ic≧2 mA), preferably at least 4 mA (i.e., Ic≧4 mA), preferably at least 10 mA (i.e., Ic≧10 mA), more preferably at least 20 mA (i.e., Ic≧20 mA) or at least 30 mA (i.e., Ic≧30 mA).

[0059] In a preferred embodiment illustrated in Figures 3b, 3c, and 5b, M1 of the N cyclotrons (10.1 to 10.M1) (2 < M1 < N, preferably M1 = N) are positioned side by side in the same plane perpendicular to their parallel Zi axes. Alternatively, as illustrated in Figure 6b, the M1 cyclotrons are preferably positioned overlapping each other, but not necessarily tilted relative to each other, with the Zi axes of two adjacent cyclotrons forming an angle preferably less than 30°. If the Zi axes of two adjacent cyclotrons form too small an angle, are parallel, or even coincide, one or both cyclotrons are preferably equipped with a steering magnet unit (15) (e.g., formed by a dipole) located downstream of the extraction outlet to steer the two individual beams (1ci or 1.i) into the cone of aperture 2θ. As shown in Figure 3b, the M1 cyclotrons are preferably positioned and configured to generate magnetic fields with rotational symmetry of order M1 between them. The M1 cyclotrons - and also the N cyclotrons - are preferably according to the invention.

[0060] In a preferred embodiment that enables reduced production and usage costs and a reduced footprint, M2 cyclotrons (10.1 to 10.M2) (2≦M2≦N) among the N cyclotrons share one or more components. Preferably, M2=N. For example, as shown in FIG. 3b, each of the M2 cyclotrons (10.1 to 10.M2) includes a dee electrode assembly (5D) and a counter dee electrode assembly (5D), and the acceleration system includes a single RF generator (7RF) configured to apply an AC high voltage to the dee electrode assemblies of the M2 cyclotrons (10.i) to generate an accelerating electric field. Alternatively, or additionally, as also illustrated in FIGS. 3c, 5a, and 5b, each of the M2 cyclotrons (10.1-10.M2) includes a coil (7C) configured to generate a magnetic field (B) passing perpendicular to the plane (X, Y), and the acceleration system includes a single magnetic field generator (7B) configured to apply current to the coils (7C) of the M2 cyclotrons (10.1-10.M2) to generate the magnetic field (B). In an alternative embodiment illustrated in FIG. 5a, which can be combined with any one or two of the previous embodiments, the M2 cyclotrons (10.1-10.M2) can share a common yoke (14) that defines a single magnetic flux circuit spanning all of the M2 cyclotrons (10.1-10.M2). In a further alternative embodiment illustrated in FIG. 6a, which can be combined with any one of the previous embodiments, the M2 cyclotrons can share a common magnetic pole.

[0061] The acceleration system of the present invention may comprise a scanner configured to scan multiple coupled spots (1s) over a predetermined area of ​​a target plane (6p). The predetermined area is preferably at least 30 cm. 2 , more preferably at least 100 cm 2 When producing epithermal neutron beams or certain isotopes, it is advantageous to scan multiple combined beams over a larger area to reduce local overheating of the target (6).

[0062] The acceleration system of the present invention may include a target (6) downstream of and adjacent to the target plane (6p) made of a material configured to emit neutrons or produce specific isotopes when a low-energy, high-intensity beam of protons or deuterons passes through a multiple-coupling spot (1s). Alternatively, instead of the target (6), the entrance of a second acceleration system including at least one acceleration device may be positioned downstream of and adjacent to the target plane (6p). In this way, the multiple-coupling beam (1c) with energy Ec and intensity Ic exiting the acceleration system of the present invention can be further accelerated to reach a second energy Ec2>Ec with approximately the same intensity Ic2≈Ic.

[0063] Equipment for administering BNCT treatment The present invention also relates to an apparatus for administering treatment by boron neutron capture therapy (BNCT), comprising an acceleration system according to the present invention, a beam shaping assembly (21s), and a treatment area, as illustrated in Figures 8 and 9a-9c. The acceleration system used in the apparatus comprises a target (6) positioned downstream or upstream of and adjacent to a target plane (6p), as discussed above. The target (6) comprises a material configured to emit neutrons when a low-energy, high-intensity, multiply coupled beam (1c) of protons or deuterons passes through a multiply coupled spot (1s). The material is preferably selected from beryllium (Be) and lithium (Li).

[0064] The beam shaping assembly 21s is configured to shape an epithermal neutron beam 22en and direct the formed epithermal neutron beam 22en toward the treatment zone 23. The treatment area is configured to receive and support a portion of the patient 23p to be treated with the epithermal neutron beam within the treatment zone 23. Figures 8 and 9a-9c show the treatment area supporting the patient in a supine position with the head located within the treatment zone 23. Of course, other configurations are possible, such as supporting the patient in a sitting or kneeling position, so long as the tumor cells to be treated with BNCT remain stable within the treatment zone 23 during treatment.

[0065] The beam shaping assembly (21s) may comprise a collimator (21c) with an outlet (21o) of the shaping assembly (21s) located at a distance (L23) preferably less than 400 mm, more preferably less than 200 mm, and most preferably less than 125 mm from the treatment zone (23).

[0066] Referring to FIG. 7, which plots the neutron yield as a function of the energy of the proton (p) or deuteron (d) beam used to irradiate various targets (6), it can be seen that a relatively low value of the energy Ec of the combined beam (1c1) or multiple combined beam (1c) is required to obtain maximum yield. The irradiation time decreases with increasing current intensity of the (multiple) combined beam (1c1, 1c). The beam current intensity Ic is preferably at least 5 mA, more preferably at least 6 mA, more preferably at least 7 mA, preferably at least 10 mA, or at least 20 mA or more. The combined beam (1c1) of the cyclotron of the present invention and the multiple combined beam (1c) generated by the acceleration system of the present invention can generate beams of such low energy and high current intensity values.

[0067] To control the orientation of the epithermal beam 22en relative to the treatment zone 23, the device of the present invention can be configured to move the epithermal beam 22en and / or the treatment zone 23 relative to each other. For example, as illustrated in Figure 9a, the treatment area can be moved relative to the epithermal beam 22en together with the patient 23p by translation along the X axis and / or rotation about the Y and / or Z axes (see Figures 9a-9c for the orientation of the axes (X, Y, Z)).

[0068] As shown in Figures 9b and 9c, the device can be configured to move the epithermal beam 22en relative to the treatment zone 23. This can be achieved by rotating the acceleration system along with the beam shaping assembly 21s about the Y axis as shown in Figure 9b and / or about the X axis as shown in Figure 9c. Of course, the device can be configured to move both the epithermal beam 22en and the treatment area, thus providing multiple degrees of freedom for optimal irradiation of the patient's tumor cells maintained within the treatment zone.

[0069] The acceleration system of the device is preferably at least 30 cm 2 , more preferably at least 100 cm 2 The target (6) is equipped with a scanner configured to scan multiple coupled spots (1s) over a predetermined area of ​​the target plane (6p), which allows the power density of the beam to be spread and homogenized over a larger area of ​​the target plane (6p) and a larger volume of the target (6). [Explanation of symbols]

[0070] 1 Combined beam 1.i Individual beams from conventional cyclotrons in the acceleration system 1.ij jth individual beam of ith cyclotron (i=1 to N, j=1 or 2) 1ci Combined beam exiting the ith cyclotron formed by beams 1.i1 and 1.i2 1c Multiple coupled beams from several cyclotrons 1si combined beam 1ci combined spot 1sij Individual spots of individual beams 1.ij 1D Dee Electrode System 5C Counterdeep Electrode Assembly 5D Dee Electrode Assembly The 5G Gap 6 Target or subsequent beamline injection point 6p target plane 7B Coil Generator 7L Local Asymmetry 7M local magnetic source 7RF Generator for Dee Electrode System 10.i ith cyclotron (i=1~N) 12.ij 12.i jth internal ion source of ith cyclotron (i=1 to N, j=1 or 2) 13 Cyclotron single extraction outlet 14 York 15 Beam bending unit 21c Beam Shaping Assembly Collimator Neutron moderator in 21m beam shaping assembly 21o Beamforming assembly exit 21s Beamforming Assembly 22fn fast neutron beam 22en epithermal neutron beam 23 Treatment Zone 23p patient 30 Rotation mechanism Eij Energy of the first / second beam 1.ij Ei Energy of the combined beam 1ci Ec Energy of multiple coupled beams (1c) Iij Current intensity of the first / second beam 1.ij Ii Current intensity of the combined beam 1ci Ic Current intensity of multiple coupled beams (1c) L23 Distance between exit of beam shaping assembly and treatment zone M is the number of cyclotrons according to the invention in the accelerating system M1 Number of cyclotrons with the specified relative positioning M2 Number of cyclotrons sharing a component N is the number of cyclotrons in the accelerating system n is the number of first and second beams forming the multiple combined beam, n = ni1 + ni2 ni1 Number of first beams forming multiple combined beams ni2 Number of second beams forming multiple combined beams i refers to the ith cyclotron (i=1~N) j refers to the jth internal ion source and corresponding individual beam (j=1 or 2) X cone axis Zi Central axis of the ith cyclotron α Half aperture of the cone of the combined beam (1ci) θ Half aperture of the cone of multiple coupled beams (1c)

Claims

1. A cyclotron (10.1) centered on the Z1 axis for generating a combined beam (1c1) of charged particles, - Protons, deuterons, hydrogen molecular ions (H ２ ＋ ), and He ions (He ２＋ or He ＋ a first internal ion source (12.11) configured to generate charged particles selected among the first ion source (12.11) and introduce the charged particles through a first slit into the cyclotron to form the first beam (1.11) of charged particles; a second internal ion source (12.12) configured to generate the same charged particles as the first internal ion source (12.11) and introduce the charged particles into the cyclotron through a second slit simultaneously with the first internal ion source (12.11) to form the second beam of charged particles, the second internal ion source (12.12) being positioned on the opposite side of the Z1 axis from the first internal ion source (12.11); a dee electrode assembly (5D) and a counter dee electrode assembly (5C) separated from each other by a gap (5G); a generator (7RF) configured to apply an AC high voltage to the Dee electrode assembly (5D) to generate an accelerating electric field in the gap (5G) to accelerate the first beam (1.11) and the second beam (1.12) of charged particles; a magnetic field system (7B, 7C) configured to generate a magnetic field parallel to the Z1 axis and to guide the first beam (1.11) and the second beam (1.12) of charged particles along a first spiral trajectory and a second spiral trajectory, respectively, passing through the accelerating electric field in the gap (5G), thereby accelerating the first beam and the second beam of charged particles each time they pass through the accelerating electric field in the gap (5G); A cyclotron (10.1) comprising: The cyclotron (10.1) is configured to create a local asymmetry (7L) of the accelerating electric field and / or the magnetic field configured to drive the combined beam (1c1) formed by the first beam (1.11) and the second beam (1.12) along the first and second trajectories through a single extraction outlet (13), wherein the directions at the level of the extraction outlet (13) of the first beam (1.11) and the second beam (1.12) forming the combined beam (1c1) form an angle (2) of less than 15°, preferably less than 10°, more preferably less than 5° in a plane perpendicular to the Z1 axis, and more preferably the two directions are substantially parallel at an angle of 2°±1°, allowing the two beams to intersect a given target plane (6p) within a combined spot (1s1) of a given diameter.

2. 2. The cyclotron according to claim 1, wherein the magnetic field system (7B, 7C) comprises a pair of coils powered by a generator (7B) and surrounding a volume of ferromagnetic material having a thickness measured along the Z1 axis, and wherein the local asymmetry (7L) of the magnetic field is created by a local variation of the thickness and / or shape of the ferromagnetic material and / or by one or more local magnetic sources (7M) selected from among coils and permanent magnets.

3. 3. The cyclotron according to claim 1, wherein the local asymmetry of the accelerating electric field is local differences in the gap geometry between the Dee electrode assembly (5D) and the counter Dee electrode assembly (5C), and / or by asymmetric geometry and / or positioning of the first internal ion source (12.11) and the second internal ion source (12.12) relative to the Z1 axis A cyclotron characterized by being produced.

4. 4. The cyclotron of claim 3, wherein the asymmetrical positioning of the first and second sources with respect to the Z1 axis is produced at least in part by offsetting the position of the second internal ion source from axial symmetry with the position of the first internal ion source with respect to the Z1 axis, the offset comprising: - circumferential direction relative to the Z1 axis, or - Radial to the Z1 axis, or - Combination of radial and circumferential directions with respect to the Z1 axis A cyclotron characterized by being any one of the above.

5. 5. The cyclotron according to claim 1, wherein the charged particles are selected from the group consisting of protons and deuterons.

6. 6. The cyclotron according to any one of claims 1 to 5, wherein the combined beam (1c1) has, at the single extraction outlet (13), an energy (E1) of less than 75 MeV per nucleon (i.e., E1≦75 MeV / A), preferably less than 5 MeV per nucleon (i.e., E1≦5 MeV / A), and a current intensity (i) of at least 1 mA (i.e., i≧1 mA), preferably at least 2 mA (i.e., i≧2 mA), preferably at least 5 mA (i.e., i≧5 mA), more preferably at least 10 mA (i.e., i≧10 mA).

7. N cyclotrons (10.i), where N≧2 and i=1 to N, are used to generate ions, preferably protons, deuterons, hydrogen molecular ions (H ２ ＋ ), and He ions (He ２＋ or He ＋ ), wherein each of the N cyclotrons is configured to emit an individual beam of the same charged particle and given energy (Eij) along a trajectory contained in a plane perpendicular to the corresponding Zi axis, and the acceleration system is configured to combine the N individual beams (1ci, 1i) accelerated from the N cyclotrons (10.i), 7. The cyclotron according to claim 1, wherein M (M=1 to N) of the N cyclotrons (10.i) have individual beams that are the combined beam (1ci), and the N individual beams form a multiple combined beam (1c), be contained within a cone of aperture (2θ) of 70° or less (i.e., 2θ≦70°), preferably 50° or less (i.e., 2θ≦50°), more preferably 25° or less (i.e., 2θ≦25°); forming N individual spots (1sij) of a given diameter on a target plane (6p) adjacent to the target (6), perpendicular to the axis (X) of the cone and located at a predetermined position, the N individual spots being inscribed in an ellipse of area (A) less than a predetermined maximum area (Am) defining a multiple combined spot (1s), the area (A) being defined as the area where 90% of the incident beam particles strike the target plane (6p), the maximum area (Am) being preferably at least 10 cm ２ , more preferably at least 50 cm ２ is And, The multiple coupled beam (1c) has an energy (Ec) at the multiple coupled spot (1s) of less than 75 MeV per nucleon (i.e., Ec≦75 MeV / A), preferably less than 5 MeV per nucleon (i.e., Ec≦5 MeV / A), and a current intensity (Ic) of at least 2 mA (i.e., Ic≧2 mA), preferably at least 4 mA (i.e., Ic≧4 mA), preferably at least 10 mA (i.e., Ic≧10 mA), more preferably at least 20 mA (i.e., Ic≧20 mA).

8. 8. The acceleration system according to claim 7, comprising M1 cyclotrons (10.1 to 10.M1) (2≦M1≦N) among the N cyclotrons, wherein the M1 cyclotrons are: - positioned side by side on the same plane perpendicular to the Zi axis, which are parallel to each other, or are positioned one on top of the other, preferably tilted relative to each other, the Zi axes of two adjacent cyclotrons preferably forming an angle of less than 30°; and / or The M1 cyclotrons are preferably positioned and configured to generate magnetic fields with rotational symmetry of order M1 between them An acceleration system characterized by:

9. In the acceleration system according to claim 7 or 8, among the N cyclotrons, M2 cyclotrons (10.1 to 10.M2) (2≦M2≦N) are each of the M2 cyclotrons (10.1-10.M2) comprises a dee electrode assembly (5D) and a counter dee electrode assembly (5C), and the acceleration system comprises a single RF generator (7RF) configured to apply an AC high voltage to the dee electrode assemblies of the M2 cyclotrons (10.i) to generate the accelerating electric field; and / or each of the M2 cyclotrons (10.1 to 10.M2) comprises a coil (7C) configured to generate a magnetic field (B) passing perpendicularly to the plane (X, Y), and the acceleration system comprises a single magnetic field generator (7B) configured to apply current to the coils (7C) of the M2 cyclotrons (10.1 to 10.M) to generate the magnetic field (B); and / or The M2 cyclotrons (10.1-10.M2) share a common yoke (14) that defines a single magnetic flux circuit spanning all of the M2 cyclotrons (10.1-10.M2).

2. An acceleration system characterized by sharing common components such as:

10. 10. An acceleration system according to any one of claims 7 to 9, comprising a scanner configured to scan the multiple coupled spots (1s) over a predetermined area of ​​the target plane (6p), said predetermined area preferably being at least 30 cm ２ , more preferably at least 100 cm ２ An acceleration system characterized by:

11. 11. The acceleration system according to claim 7, further comprising a target (6) adjacent to the target plane (6p) and made of a material configured to emit neutrons or specific isotopes when the low-energy or medium-energy high-intensity beam of protons or deuterons passes through the multiple coupling spots (1s).

12. 10. An acceleration system according to any one of claims 7 to 9, characterized in that the target plane (6p) is upstream of and adjacent to an inlet of a second acceleration system comprising at least one acceleration device.

13. 1. An apparatus for administering boron neutron capture therapy (BNCT) treatment, comprising: a target (6) made of a material adapted to emit neutrons when a beam of accelerated protons or deuterons passes through it, said material being preferably chosen among beryllium (Be) and lithium (Li); ・ a cyclotron (10.1) according to any one of claims 1 to 6, configured to emit a combined beam (1c1) of protons or deuterons, or - an acceleration system according to any one of claims 7 to 11, configured to emit a multiple combined beam (1c) of protons or deuterons Either of the above, a beam shaping assembly (21s) configured to form an epithermal neutron beam (22en) and direct said epithermal neutron beam (22en) thus formed towards the treatment zone (23); a treatment area (23) configured to receive and support a portion of a patient (23p) to be treated with the epithermal neutron beam within the treatment zone (23); and, An apparatus comprising:

14. 14. The device according to claim 13, wherein the beam shaping assembly (21s) comprises a collimator (21c) with an outlet (21o) of the shaping assembly (21s), the outlet (21o) being located at a distance (L23) preferably less than 400 mm, preferably less than 200 mm, more preferably less than 125 mm from the treatment zone (23).

15. 15. The device according to claim 13 or 14, by moving the treatment zone (23) and the patient (23p) relative to the epithermal beam (22en) while its position remains fixed; and / or by moving the epithermal beam (22en) relative to the treatment zone (23) whose position remains fixed, the device comprising a rotation mechanism (30) configured to rotate and guide the combined beam (1c) and the epithermal beam (22en); or by moving both the treatment zone (23) and the epithermal beam (22en) relative to each other as described above; 10. An apparatus configured to move the epithermal beam (22en) relative to the treatment zone (23).

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