Use of a linear ion accelerator for atrial fibrillation treatment and ion accelerator system
阅读说明：本技术 用于心房纤维颤动治疗的线性离子加速器的使用和离子加速器系统 (Use of a linear ion accelerator for atrial fibrillation treatment and ion accelerator system ) 是由 尤格·奥马尔蒂 于 2014-08-13 设计创作，主要内容包括：治疗心房纤维颤动(AF),动静脉畸形(AVMS)和局灶性癫痫病灶的离子加速系统(12)的应用；该系统(12)是由脉冲离子源(1),预加速器(3)和一个或多个运行在频率在1GHz以上并且重复率在1Hz和500Hz之间的直线加速器或多个直线加速器(5,6,7)组成。从复合设施(12)输出的粒子束可以(i)在强度(离子源(1)的作用),(ii)在沉积深度(通过独立地调整提供直线加速器单元的功率源的无线电频率)和(iii)相对于所述中央离子束方向的横向方向(通过改变放置在患者上游的两个正交扫描磁性线圈的电流)变化。在几毫秒内和在三个正交方向调整患者身体内每个能量沉积的位置是可能的。这使加速器系统(12)非常适合照射跳动的心脏。(Use of an ion acceleration system (12) for treating Atrial Fibrillation (AF), arteriovenous malformations (AVMS) and focal epileptic lesions; the system (12) is composed of a pulsed ion source (1), a pre-accelerator (3) and one or more linacs (5, 6, 7) operating at a frequency above 1GHz and at a repetition rate between 1Hz and 500 Hz. The particle beam output from the complex (12) can be varied (i) in intensity (action of the ion source (1)), (ii) in deposition depth (by independently adjusting the radio frequency of the power source providing the linac unit) and (iii) in a direction transverse to the central ion beam direction (by varying the current of two orthogonally scanned magnetic coils placed upstream of the patient). It is possible to adjust the position of each energy deposit within the patient's body within a few milliseconds and in three orthogonal directions. This makes the accelerator system (12) well suited for illuminating a beating heart.)
1. An accelerator complex (12), comprising:
an ion source (1) configured to generate beam pulses of ions having an atomic number between 1 (protons) and 10 (neon ions);
a pre-accelerator (3) configured to accelerate the rate of beam pulses;
a high energy portion (13) configured to receive beam pulses from a pre-accelerator (3), the high energy portion (13) comprising at least one linac (5, 6, 7) comprising a plurality of cells and the high energy portion being configured to:
i. operating at a frequency greater than 1GHz, a repetition rate between 10Hz and 400Hz, and
varying the energy of the output accelerated ions by acting on the rf source of at least one linac (7) to switch off some of the cells and varying the power and phase of the rf power pulses sent to the last active cell of the last part of the linac, the output accelerated ion formation points of the beam pulses delivering a dose of beam pulses to a target region of the patient's body;
a three-dimensional feedback system configured to vary the two lateral positions and the depth within the patient's body before each point is transmitted such that the dose of the beam pulses delivered by each point is confined to a target region to reduce unnecessary irradiation of non-target regions; and
a high energy beam transmission channel (HEBT) with an associated magnetic system that transmits the beam pulses forming each spot from the high energy portion (13) to a treatment room of the patient.
2. The ion accelerator complex (12) of claim 1, wherein the configuration of the cells and the configuration of the three-dimensional feedback system are such that a change in depth through the three-dimensional feedback system corresponds to a change in energy of the output accelerated ions.
3. The ion accelerator complex (12) of claim 1, wherein the three-dimensional feedback system is configured to vary the two lateral positions and the depth within the patient's body before transmitting each point to compensate for motion of the target region such that the dose of beam pulses delivered by each point is confined to the target region so as to reduce unnecessary irradiation of non-target regions.
4. The ion accelerator complex (12) according to any one of claims 1 to 3, characterized in that the high energy section (13) comprises two or three linac sections and one or more linac sections (5, 6, 7) operate at different frequencies.
5. The ion accelerator complex (12) according to any one of claims 1 to 3, characterized in that the complex comprises one or more pre-accelerators (3) configured to accelerate the rate of beam pulses.
6. The ion accelerator complex (12) according to any one of claims 1 to 3, characterized in that the pre-accelerator (3) is a room temperature or superconducting linac or a radio frequency quadrupole accelerator (RFQ).
7. The ion accelerator complex (12) according to any one of claims 1 to 3, characterized in that the pre-accelerator (3) is a room temperature or superconducting cyclotron/synchrocyclotron, or a FFAG accelerator.
8. The ion accelerator complex (12) according to any one of claims 1 to 3, characterized in that the ion source (1) is computer controlled to adjust the delivered dose at each point.
9. The ion accelerator complex (12) according to any one of claims 1 to 3, characterized in that the complex comprises a correlation arrangement (14) that transmits pulsed beams in a computer controlled manner to a room, robot chair, bed, or other location (11a, 11b, 11c) for patient treatment, the correlation arrangement (14) comprising fan-out magnets (9) associated with intermediate beam transmission lines (10a, 10b, 10c), each having two magnets configured for transverse scanning and a monitoring system.
10. The ion accelerator complex (12) of any of claims 1 to 3, wherein the linac (5, 6, 7) is a 3GHz linac configured to accelerate4He2+Ions and configured to operate with the following parameters:
11. a method for Atrial Fibrillation (AF) treatment by "spot scanning" and "multi-painting" techniques, characterized by comprising the output of accelerated ions from an accelerator complex according to claim 1, wherein a three-dimensional feedback system is foreseen, so as not to require the unwanted irradiation of the tissues to be preserved.
12. A method for treatment of arteriovenous malformations (AVMs) or focal epileptic lesions comprising outputting accelerated ions from the accelerator complex of claim 1, wherein a three-dimensional feedback system is foreseen to eliminate the need for unwanted irradiation of the tissue to be preserved.
13. Use of an ion accelerator complex (12) according to any of claims 1 to 10, characterized in that the accelerator complex (12) is used for medical treatment.
14. Use of an ion accelerator complex (12) according to any of claims 1 to 10, characterized in that the accelerator complex (12) is used for the treatment of cardiac or cranial focal diseases.
15. Use of an ion accelerator complex (12) according to any one of claims 1 to 10, characterized in that the accelerator complex (12) is used for the treatment of atrial fibrillation.
16. Use of an ion accelerator complex (12) according to any one of claims 1 to 10, characterized in that the accelerator complex (12) is used for the treatment of arteriovenous malformations (AVMs) or focal epileptic lesions.
17. An accelerator complex, comprising:
an ion source (1) configured to generate beam pulses of ions having an atomic number between 1 (protons) and 10 (neon ions);
a pre-accelerator (3) configured to accelerate the rate of the pulse beam;
a high energy part (13) configured to receive beam pulses from the pre-accelerator (3), the high energy part (13) comprising at least one 3GHz linac (5, 6, 7) configured to accelerate the beam pulses4He2+Ions, a beam pulse being generated by the ion source (1) and configured to operate with the following parameters:
The high-energy portion (13) is configured to add by acting on at least one straight lineVarying the output acceleration on the radio frequency source of the speeder (7)4He2+Energy of ions, output acceleration of said pulsed beam4He2+An ion formation point delivering a dose of the pulsed beam to a target region of a patient's body;
a three-dimensional feedback system configured to vary the two lateral positions and the depth within the patient's body before each point is transmitted such that the dose of beam pulses delivered by each point is limited to a target region to reduce unnecessary irradiation of non-target regions; and
a high energy beam transmission channel (HEBT) with an associated magnetic system that transmits the pulsed beam forming each spot from a high energy portion (13) to the patient's treatment room.
18. An accelerator complex for charged nuclear particles having an atomic number between 1 (protons) and 10 (neon ions), comprising:
an ion source (1);
a pre-accelerator (3); and
a high-energy portion (13),
wherein the high energy section (13) comprises at least one linac (5, 6, 7) comprising a plurality of accelerator units and a radio frequency source, the high energy section (13) being configured to:
i. the frequency of the operation is more than 1GHz, and the repetition rate is between 1Hz and 500 Hz; and
adjusting the energy of the output accelerated particles by changing the radio frequency source of the last active accelerator unit of the last linac of said at least one linac (5, 6, 7).
19. The accelerator complex (12) according to claim 18, further comprising a feedback system arranged to follow cardiac motion in three-dimensional space in order to deliver a necessary dose at a target region within a patient.
20. The accelerator complex (12) according to claim 19, wherein the energy of the output accelerated particles is adjusted to change their intensity, depth of deposition and lateral position according to a feedback system.
21. Accelerator complex (12) according to any of the preceding claims 18 to 20, further comprising a magnetic tunnel (8) for transmitting High Energy Beams (HEBT) downstream of the high energy section (13).
22. Accelerator complex (12) according to any of the preceding claims 18 to 21, characterized in that the associated system comprises a transmission channel of the pulsed beam to the treatment room of the patient.
23. Accelerator complex (12) according to any of the preceding claims 18 to 22, characterized in that the high energy section is configured to adjust the radio frequency source by changing the power and phase of the radio frequency power pulse sent to the last active unit.
24. Accelerator complex (12) according to any of the preceding claims 18 to 23, characterized in that the high energy section (13) is configured to switch off some of the last linac units to produce the last active unit.
25. Accelerator complex (12) for ion acceleration according to any of the previous claims 18 to 24, characterized by the fact that the accelerated particles are ions with atomic number equal to 2 (helium ions).
26. Accelerator complex (12) for ion acceleration according to any of the claims 18 to 24, characterized by the fact that the high energy section (13) also contains two or three linac sections and some linac sections (5, 6, 6) run at different frequencies.
27. Accelerator complex (12) according to any of claims 18 to 24, characterized in that one or more particle accelerators, here collectively denominated pre-accelerators (3), are foreseen to supply energy to the particles produced by the ion source (1) before the ion beam is injected into the linacs (5, 6, 7) behind them.
28. Accelerator complex (12) according to any of claims 18 to 24, characterized in that the pre-accelerator (3) is a room temperature or superconducting linac or a radio frequency quadrupole accelerator (RFQ).
29. Accelerator complex (12) according to any of claims 18 to 24, characterized in that the pre-accelerator (3) is a room temperature or superconducting cyclotron/synchrocyclotron or FFAG accelerator.
30. The accelerator complex (12) according to any one of claims 18 to 24, wherein the ion source (1) is computer controlled to adjust the delivered dose at each point.
31. Accelerated compounding facility (12) according to any of claims 18 to 24, characterized in that the relevant layout of computer controlled magnetic channels (14) comprises "fan out" magnets (9) associated with intermediate beam transmission lines (10a, 10b, 10c), and-at each intermediate beam transmission line-two magnets for transverse scanning and a monitoring system, the magnetic channels transmitting pulsed beams to rooms, robot chairs, beds etc. (11a, 11b, 11c) for patient treatment.
32. Accelerating complex (12) according to any of claims 18 to 24, characterized by the fact that the linacs (5, 6, 7) are accelerating4He2+A 3GHz linear accelerator of ions configured to operate with the following parameters:
33. the accelerator complex (12) of any of claims 18-32, configured to perform one or more of "point scanning" and "multi-drawing".
34. The accelerator complex (12) according to claim 32, wherein the accelerator complex (12) is configured to perform techniques in the treatment of atrial fibrillation (AV) or arteriovenous malformations or focal epileptic lesions.
35. A method for atrial fibrillation therapy, characterized by the fact that it consists in outputting accelerated ions from the accelerator complex according to claim 18, by means of "point scanning" and "multi-painting" techniques, in which a three-dimensional feedback system is foreseen, without the need of unwanted irradiation of the tissues to be preserved.
36. A method for treatment of arteriovenous malformations (AVMs) or focal epileptic lesions comprising outputting accelerated ions from the accelerator complex of claim 18, wherein a three-dimensional feedback system is foreseen without unnecessary irradiation of the tissue to be preserved.
37. Use of an accelerator complex (12) according to any of claims 18 to 34, characterized in that the accelerator complex (12) is used for medical treatment.
38. Use of an ion acceleration complex (12) according to any of the claims 18 to 34, characterized in that the accelerator complex (12) is used for the treatment of cardiac or cranial focal diseases.
39. Use of an accelerator complex (12) according to any one of claims 18 to 34, characterized in that the accelerator complex (12) is used for the treatment of atrial fibrillation.
40. Use of the accelerator complex (12) according to any one of claims 18 to 34, wherein the accelerator complex (12) is used for the treatment of arteriovenous malformations (AVMs) or focal epileptic lesions.
Technical Field
The present invention relates to the use of linear ion accelerators (commonly referred to as "linacs") for the treatment of Atrial Fibrillation (AF) and to ion accelerator systems, or complexes, for treating atrial fibrillation using the known "point" scanning and so-called "multi-picture" techniques according to the preambles of claims 1 and 2.
Background
Hadron therapy is well known as modern radiation cancer therapy using a beam of heavily charged nuclear particles with protons or atomic mass numbers greater than 1.
Several years ago, it was proposed to treat atrial fibrillation using the same particle beam using similar techniques. Limitations and disadvantages of this approach are noted later.
Atrial fibrillation
Atrial Fibrillation (AF) is the most common type of cardiac arrhythmia in the elderly, and is a high risk factor for heart attacks. The risk of lifelong atrial fibrillation is 25%. The prevalence increases from 0.1% in adults under the age of 55 to 9.0% in people over the age of 80. Among patients with atrial fibrillation, the average age of men is 67 years, women are 75 years, and 1% of the total population suffers from atrial fibrillation. It is predicted that this proportion will increase 2.5 times in the next 50 years, reflecting an increasing proportion of the elderly population.
In the united states, there are about 3 million episodes of atrial fibrillation disease per year, and 20% of all cases with stroke (75,000 per year) can be attributed to atrial fibrillation; the total cost of treating atrial fibrillation is about seven billion dollars per year. In europe, the corresponding cost is around 1% of the annual healthcare expenditure. The current methods for treating atrial fibrillation are: drug management of atrial fibrillation, drug administration to reduce the risk of stroke, cardiac reversal (electroconvulsive therapy), catheter ablation, and the wearing of appropriate cardiac pacemakers.
Catheter ablation interrupts the abnormal electrical circuit in the heart. The catheter is introduced into the heart through the patient's vein and the electrical activity is recorded. When an abnormal source is found, an energy source (e.g., high frequency radio waves that generate heat) is transmitted through one of the catheters to destroy the tissue.
This technique is invasive and rejected by many patients.
The method recently proposed by the inventors to destroy dangerous electronic connections in the heart using a charged hadron beam may be a valuable non-invasive alternative. Furthermore, the patient does not need to be anesthetized and does not experience any discomfort during a standard radiation treatment session. Relevant papers in this field are:
ch burt, R. lngen hart cabrick and M. durant, particle therapy for non-cancerous diseases, medical. physics. 39(2012) 1716.
A. comstein banks, h.i. leman, C-garifor, D-park, M-durant and C-bert, non-invasive carbon ion beam scanning for the treatment of the effects of cardiac motion on the pulmonary veins in atrial fibrillation. GSI scientific advisory report, p.472.
The use of hadron beams for the treatment of atrial fibrillation according to the present invention is a new technique based on the development of sophisticated X-ray beam techniques, for example, in:
a charima, D king, G wedelisy, T fugeti, a jack, T sumamantara and p marqui, non-invasive stereotactic radiosurgery to create ablative lesions in the atrium (cyberreart corporation), heart rhythm 7(2010) 802.
R.M.Sulivin and A.Mazur, stereotactic mechanical radiosurgery (CyberHeart corporation): a network revolution of cardiac ablation? Heart rhythm 7(2010) 811.
It may be noted that hadron is certainly preferred with respect to X-rays, since it allows to well localize the administered drug-at the end of the charged particle range-the energy of maximum density is deposited in the patient's body, according to the energy decay law; the same reason is that particles are better than X-rays for treating solid cancers near critical organs.
In a continuing pilot study of this new technology, the irradiation dose "shines" with sub-millimeter accuracy at the energy decay law peak "point" to the relevant target tissue in the pulsating heart. In doing so, before each point is sent, it is necessary to rapidly vary its two lateral positions and the depth within the body in order to compensate for the positional shift due to (i) the respiratory cycle and (i i) the patient's heart beat.
Therefore, any optimal treatment in the future must include a three-dimensional feedback system to reduce unnecessary exposure of surrounding healthy tissue, focus the dose on the relevant target, and treat the patient in a short time.
The view of many experts working on this new technology is that carbon ions are preferred over protons because they are triple scattered and diverged, resulting in approximately ten times less dot coverage. However, the accelerator required is much larger because-the same penetration is made in the patient-the magnetic stiffness of the carbon ions is three times greater than the magnetic stiffness of the corresponding proton beam.
It can further be observed that in the field of hadron beam therapy of cancer, two types of accelerators are used: cyclotrons (isochronous or non-isochronous synchronous; conventional or superconducting) and synchrotrons. There are several companies offering proton and/or carbon ion therapy treatment centers based on such accelerators. These scientists are open to using protons and ions for atrial fibrillation and planning to use accelerators.
The inventors have proposed the use of a linear accelerator (linac) of protons and light ions for the treatment of cancer:
1) us patent 6888326B2 "linear accelerator for accelerating an ion beam, U amaldi, M claisen, R zennalo.
2) Us patent 7554275B2 "proton accelerator complex for radioisotope therapy, U amaldi.
3) European patent EP2106678B1 "ion accelerator system for treatment with hadron, inventor: u Amaidi, S Blanconi, G Maglin, P Pierss, R Zenalo.
4) Us patent 8405056B2 "ion accelerator system with hadron therapy, inventor: u Amaidi, S Blanconi, G Maglin, P Pierss, R Zenalo.
Similar linacs have many advantages in cancer treatment. The inventors have now unexpectedly shown that the advantages provided by these linacs also relate to recent advances in the treatment of atrial fibrillation.
Disclosure of Invention
The main object of the present invention is to propose a linear ion accelerator (linac) and related ion accelerator system of charged particles for the treatment of atrial fibrillation, which are free from the limitations and drawbacks of the known art, which systems or complex, in part, are already generally known and compact and lightweight to operate, requiring only a small mounting surface, which makes installation in a medical center easier.
To further achieve this object in different aspects, a linear ion accelerator (or linac) and a corresponding ion accelerator system for atrial fibrillation treatment have the features of claims 1 and 2. Further developments can be gathered from the dependent claims.
The use of a linear ion accelerator for treating atrial fibrillation and a corresponding apparatus for its implementation in accordance with the present invention, together with several important advantages that the invention may achieve in different aspects, are discussed below.
According to the invention, the proposed system is based on a hadron linear accelerator operating at high frequency and high gradient; they have many individually powered "acceleration units". Such a linear accelerator can accelerate any type of ions.
Within the scope of the present invention, the inventors further note that helium ions are particularly characteristic because, for acceleration, they require a linear accelerator that is shorter relative to carbon ions, they produce spots that are smaller in lateral and longitudinal dimensions than those of a proton beam, and they deposit the same dose at the same depth within the patient.
To meet the above-described need, ions, particularly helium ions, are accelerated to the energy required to treat atrial fibrillation by one or more linac sections operating at high frequencies greater than 1GHz according to the present invention. For ions in the 180 mm depth range, typical maximum kinetic energies are: 160MeV protons, 640MeV (160MeV/u) helium ions and 3600MeV (300MeV/u) carbon ions. The integral of the corresponding accelerating electric field is 160MV, 320MV and 600 MV.
High frequency ion linacs can operate in very large acceleration gradients (up to 40-50MV/m), and therefore there is a limit to the length of the accelerating structure required to achieve these energies. However, these figures directly show that the helium ion linac for treatment of atrial fibrillation is about twice as long as the proton linac, and the carbon ion linac is about twice as long as the helium ion linac.
The injector of the high frequency linac (herein named "pre-accelerator"), specifically for ions at low speed, may be a linear accelerator, or a circular accelerator (cyclotron, synchrocyclotron, fixed field alternating gradient accelerator or others) or a combination of two or more of these known accelerators.
The output ion beam of the linear accelerator for treating atrial fibrillation is pulsed, the pulse being 3-5 microseconds long: they follow another varying repetition rate-as required-between 1Hz and 500 Hz.
At the final linac, the energy per spot (and the depth of deposition) can be adjusted by switching off some cells and by varying the power and phase of the rf power pulse sent to the last active cell. Thus, a linear accelerator, which is an ideal accelerating device for an "effective" dose-spreading system: from pulse to pulse, the ion energy and number of ions in the pulse can be adjusted electronically and within a few milliseconds. The energy is adjusted by acting on the power pulses and their phases-sent to the acceleration cell-as described above, while the number of ions is typically adjusted by acting on the electrostatic lens of the particle source, which as described produces pulses 3-5 microseconds long with a repetition rate between 1Hz and 500 Hz.
Furthermore, in view of the high repetition rate, each "voxel" of the target tissue may be accessed at least ten times in a treatment mode commonly referred to as "multi-painting".
According to the present invention, optimal treatment of atrial fibrillation can be achieved by a combination of multi-picture and three-dimensional feedback systems.
It must be emphasized that in cyclotrons the modulation of the energy is achieved by mechanical movement of suitable absorbers, which results in unwanted activation of the surrounding material, typically requiring more than 10 meters of magnet to "clean" the ion beam downstream of the absorber. Furthermore, it typically takes 100 milliseconds to tune such absorbers. With conventional synchrotrons, fast three-dimensional adjustment of the spot position by electrons is not feasible because the energy per acceleration period typically varies every one or two seconds.
Generally, high frequency linacs are preferred over all others because the ion beam energy and the number of particles (set by the action of very low energy particle sources) delivered to the tumor target varies from pulse to pulse (i.e., every few milliseconds).
The time and intensity configuration of the high repetition rate pulsed ion beam is particularly suited for dose delivery in atrial fibrillation therapy, as in PSI center, Provence Scherrer institute, Philippine root, Switzerland (E. Pedersoni et al, Provence Scherrer institute 200 MeV proton therapy project: conceptual design and utility, medical Physics, 22(1), (1995)37), because of the "multiple pictures" used, the use of the "spot scanning" technique is improved.
In addition to optimal time and intensity configuration of the ion beam, the use of a high gradient ion linac according to the present invention presents other advantages.
First, the ion linac is lighter, easier to carry and install, and is characterized by a modular structure, duplicated from identical high-tech units, with little change to each acceleration module, relative to existing cyclotrons and synchrotrons. Secondly, the system is provided in a compact configuration requiring only minimal volume and mounting surface, thus making it easy to install in a medical center.
Furthermore, the high frequency of the linac means low power consumption, which can reduce development costs.
In summary, the present invention allows for the creation of a compact, low power complex device, or apparatus, that uses a three-dimensional spot scanning technique with multiple picture and feedback functions to deliver a dose that counteracts the motion of the illuminated heart, relative to other hadron accelerators that treat atrial fibrillation.
According to another aspect of the invention, this accelerator complex may also be used to treat arteriovenous malformations (AVMs) and focal epileptic lesions, which may be irradiated with a proton beam (and other ions) to a subject. This is described in f.j.a.i. fornemen and others in "stereotactic proton beam therapy for intracranial arteriovenous malformations", journal of radiocytobiology 62(2005)44, and in M · quiniger et al, in "radiosurgery for epilepsy": clinical experience and potential antiepileptic mechanisms, epilepsy, J.53 (2012)7, and the like.
Drawings
Further characteristics, advantages and details of the use of a linear ion accelerator for the treatment of atrial fibrillation and of a corresponding ion accelerator system according to the invention will be more or less apparent from the description of the following application documents and the accompanying drawings of an embodiment of a suitable ion accelerator system as an example.
According to a single reference figure, the main components of the hadron accelerator complex to which the invention applies are:
1. an ion source generating pulses of ions about 5 microseconds long with a repetition rate between 1Hz and 500 Hz;
2. a low energy beam transport track (L EBT-low energy beam transport);
3. a pre-accelerator, which may be a radio frequency quadrupole accelerator (RFQ) or a cyclotron or a synchrocyclotron or a special type of linear accelerator capable of accelerating very slow hadrons;
4. a medium energy beam transmission channel (MEBT);
5. a first linear accelerator component having a radio frequency greater than 1 GHz;
6. a second linac section having a radio frequency that is a multiple of one of the radio frequencies of the first linac section;
7. a third linac section having a radio frequency that is a multiple of one of the radio frequencies of the second linac section;
8. a high energy ion beam transport channel (HEBT) to transport the accelerated ion beam to a patient treatment room;
9. a fan-out magnet, which in its preferred embodiment, can send beam pulses of variable energy and intensity to the treatment room;
10. a system of ion beam transmission lines directed to the treatment room and a monitoring system, each transmission line comprising two scanning magnets (the size of the irradiation area is defined by moving the ion beam vertically and horizontally);
11. an automated chair, the heart of a seated patient receiving a prescribed dose through a Treatment Planning System (TPS);
12. hadron accelerator devices or complex facilities of the present invention;
13. a linear accelerator component or subsystem complex (5; 6; 7);
14. an ion pulse transmission line system directed at a patient to be irradiated.
Detailed Description
It is emphasized that the subsystems or 5, 6 and 7 components of the figures are not necessarily all present in each embodiment at the same time.
More precisely, with reference to fig. 1, the hadron accelerator complex 12 according to the invention comprises various types of accelerators connected in series, namely a pre-accelerator 3 and some linac sections 5, 6, 7; the oscillation frequency can be gradually increased to have a higher gradient at the final linac, thereby reducing the overall length of the system. To simplify the overall solution, some of the three linac sections 5, 6, 7 may be omitted.
A pre-accelerator 3 is supplied by the ion source 1. Its output ion beam may be continuous or, more preferably, a modulated pulse of a few microseconds long with a repetition rate of 1-500Hz, so that a number of ions are transmitted to the first linear accelerator section through the MEBT 4. 5 is the lowest and does not produce unwanted radiation in subsequent elements.
Each linac section 5, 6, 7 is composed of an "accelerating cell", which may be a traveling wave linac or a standing wave linac, and has various structures of drift tube linacs (DT L), including an IH drift tube linac, a CH drift tube linac, a coupled cavity linac, and the like, using a lateral electric field radial field (C L USTER), an edge-coupled drift tube linac (SCD L), a cell-coupled linac (CC L), or other accelerators, depending on the hadron speed of acceleration.
These types of acceleration structures are well known and additional description appears in the applicant's us 6888326B2, us 7423278B2 and us 7554275B2, which are incorporated by reference in the present application for further details.
It can be said that, with an average gradient equal to 30MV/m, the total voltage required to achieve AV treatment-protons: about 160 MV; helium ion: about 320 MV; carbon ion: about 600MV — total length of linear accelerator approximately: 5 m for protons, 10 m for helium ions, and 20m for carbon ions.
Typically, the component of the linac that produces the greatest acceleration gradient is the component 7 shown in fig. 1. As mentioned above, it is usually the last component to be independently powered, so that the energy of the output particles can be adjusted from pulse to pulse.
The accelerated ion beam is transported through the HEBT channel 8 to the treatment room. In some versions of the embodiment this is achieved with a fan-out magnet 9, while in other embodiments, like those used in cancer treatment centers provided with rotating gantries, a standard ion beam transport design will be chosen.
The patient may be seated in an automatic chair 11 for treatment as shown in the preferred embodiment or may be lying in a computer controlled moving bed.
In the application of the invention to the treatment of atrial fibrillation, the particle beam emitted by the complex 12, 8, may vary as follows:
intensity (acting on the ion source (1)), (ii) deposition depth (by independently adjusting the rf power supply to the linac accelerating unit), and (iii) lateral direction with respect to the central beam (by varying the current to two orthogonal scanning magnet coils placed upstream of each patient).
Adjusting the position of each energy deposit within the patient's body in three orthogonal directions, possibly within a few milliseconds, makes the accelerator system 12 well suited for irradiating a beating heart.
As an example, table 1 below summarizes possible scenarios for the complex 12, including:
(A) a computer controlled helium source 1-which may be of the Electron Cyclotron Resonance (ECR) type (suitably tuned to obtain a pulsed beam with repetition rate of 1-500 Hz), or of the electron beam ion source type (EBIS) or others;
(B) a cyclotron or synchrocyclotron 3 of 60MeV/u with coils at room temperature or in superconducting conditions;
(C) a model L IBO7 unit-coupled linac operating at 3GHz and consisting of 10 individually powered units.
The farez group and CPI corporation, usa, produce the 3GHz klystron needed to implement the aforementioned embodiments.
In the preferred embodiment of the linac of table 1, the pre-accelerator is superconducting. Its magnetic field configuration and dimensions are similar to those of the superconducting cyclotron sold by warian systems of medicine (palo alto, usa) for cancer proton beam therapy. The magnet has a diameter of 3.2 meters and a height of 1.6 meters, and only about 40 kilowatts need to be consumed to achieve low temperatures. The total consumption is less than 200 kw. Source 1 is axially implanted with a pulse of helium ions.
Watch 13GHz4He2+Examples of ion linacs
From the description of the various forms of structure and function implemented using ion acceleration apparatus or complex, it will be noted that the present invention effectively achieves the stated objects and the advantages mentioned when treating atrial fibrillation.
Individual components and combinations thereof may be modified and varied in construction and/or size to suit particular circumstances without departing from the scope of the invention as described by the following claims.
Literature reference
Some publications in the field of high-frequency linacs for hadron therapy are listed:
r.w. ham, k.r. klendl and j.m. baud, preliminary design of dedicated proton therapy linear accelerators, at PROC. PAC90, volume 4 (san francisco, 1991), 2583.
U.S. Omeiti, M.Glan Duerfu and L Piccadi (EDS), RITA networks and compact proton accelerators, INFN, Frascatti, 1996, design of ISBN88-86409-08-7, Chapter 9, in "Green book".
L structural design development of TOP linear accelerator SCDT L, Nuclear instrumentation and method A, 425(1999)8, Percadi, C. Row.
Proton therapy by u, olmarti et al, linear accelerator, booster: construction and prototype testing, nuclear instrumentation and methods 521(2004) 512.
U, omaldi, s, brazzini, and p, proggio, review, accelerate, science, technology for hadron high frequency linear accelerators. 2(2009)111.
U, olmarti et al, hadron accelerator: from the Lorentzian cyclotron to the linear accelerator, nuclear instrumentation method A620(2010) 563.
C. demanny et al, accelerated testing of a 3ghz proton linear accelerator (L IBO) for hadron therapy, nuclear instrumentation and methods 681(2012) 10.
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