Ion acceleration complex for the treatment of atrial fibrillations
View Patent ↗A system ( 12 ) is proposed for the acceleration of ions to treat Atrial Fibrillation (AF), arteriovenous malformations (AVMS) and focal epileptic lesions; this system ( 12 ) includes a pulsed ion source ( 1 ), a pre-accelerator ( 3 ) and one or more linear accelerators or linacs ( 5, 6, 7 ) operating at frequencies above 1 GHz with a repetition rate between 1 Hz and 500 Hz. The particle beam coming out of the complex ( 12 ) can vary (i) in intensity, (ii) in deposition depth and (iii) transversally with respect to the central beam direction. The possibility of adjusting in a few milliseconds and in three orthogonal directions, the location of each energy deposition in the body of the patient makes that system of accelerators ( 12 ) perfectly suited to irradiation of a beating heart.
1. An accelerator complex ( 12 ) comprising:
an ion source ( 1 ) configured for producing beam pulses of ions with an atomic number between 1 (protons) and 10 (neon ions),
a pre-accelerator ( 3 ) configured for accelerating rates of the beam pulses,
a high-energy section ( 13 ) configured to receive beam pulses from the pre-accelerator ( 3 ), the high-energy section ( 13 ) containing at least one linac ( 5 ; 6 ; 7 ) comprising a plurality of units and configured to:
(i) run at a frequency larger than 1 GHz with a repetition rate between 10 Hz and 400 Hz, and
(ii) vary energy of outgoing accelerated ions by acting on the radiofrequency sources of at least one linac ( 7 ) to switch off a number of units, and to vary the power and the phase of the radiofrequency power pulses sent to the final active units of a last section of the linac,
said outgoing accelerated ions of beam pulses forming a spot that deliver a dose of beam pulses to a target area of a patient's body,
a three-dimensional feedback system configured to vary, before sending every spot, two transverse positions and a depth in the patient's body so as to compensate for the movements of a targeted area such that the dose of beam pulses delivered by every spot is limited to a targeted area in order to reduce unwanted irradiation to non-targeted areas, and
a High Energy Beam Transport channel (HEBT) with an associated magnet system that transports the beam pulses forming every spot from the high-energy section ( 13 ) to a treatment room of said patient,
wherein the configuration of the units and the configuration of the three-dimensional feedback system is such that the variation of the depth by the three-dimensional feedback system corresponds to the variation of energy of outgoing accelerated ions.
2. The complex for ion acceleration ( 12 ) according to claim 1 , wherein the high-energy section ( 13 ) contains two or three linac section(s) and one or more linac sections ( 5 ; 6 ; 7 ) run at different frequencies.
3. The complex for ion acceleration ( 12 ) according to claim 1 , wherein the complex comprises more than one pre-accelerator ( 3 ) configured for accelerating rates of the beam pulses.
4. The complex for ion acceleration ( 12 ) according to claim 1 , wherein the pre-accelerator ( 3 ) is a room temperature, a superconducting Linac, or a Radio Frequency Quadrupole (RFQ).
5. The complex for ion acceleration ( 12 ) according to claim 1 , wherein the pre-accelerator ( 3 ) is a room temperature, a superconducting cyclotron/synchrocyclotron, or a FFAG accelerator.
6. The complex for ion acceleration ( 12 ) according to claim 1 , wherein the ion source ( 1 ) is computer controlled so as to adjust the dose delivered in every single spot.
7. The complex for ion acceleration ( 12 ) according to claim 1 , wherein the complex comprises an associated layout ( 14 ) of pulse beam transport to rooms, robotic chairs, or beds other locations ( 11 a , 11 b , 11 c ) for treatment of patients in a computer controlled manner, the associated layout ( 14 ) includes a magnet fan-out ( 9 ) with associated intermediate beam transport lines ( 10 a , 10 b , 10 c ), each intermediate beam transport line having two magnets configured for transverse scanning and a monitoring system.
8. The complex for ion acceleration ( 12 ) according to claim 1 , wherein the linac ( 5 ; 6 ; 7 ) is a 3 GHz linac that is configured to accelerate 4He2+ ions and is configured to operate with the following parameters:
Frequency [MHz]
2998
Q (ion charge)
2
A (ion mass number)
4
Input energy [MeV/u]
60
Total input energy [MeV]
240
Maximum output energy [MeV/u]
160
Maximum total output energy [MeV]
640
Number of cells in an accelerating structure
18-16
(or tank)
Iris diameter [mm]
7
Number of units
10
Unit length [m]
0.75-1.05
Total length of the linac [m]
9.5
Average transit time factor T
0.85
Effective Shunt Impedance's = ZT2 [MΩ/m]
53-77
Average electric field on the axis E0 [MV/m]
33
Maximum surface electric field [MV/m]
140
Transverse normalized acceptance at 2 rms
2.4
[π mm mrad]
Peak power per unit [MW]
10
RF Pulse duration [μs]
4
Repetition rate [Hz]
120
Fraction of time with beam (or duty cycle) [%]
0.048
Average power to feed the 10 klystrons [kW]
150.
9. A method for the treatment of atrial fibrillation by spot scanning and multi-painting technique, comprising administering to a patient in need thereof accelerated ions from an accelerator complex according to claim 1 , wherein a three-dimensional feedback system is foreseen to treat the patient without unwanted irradiation of the tissues that need to be spared.
10. A method for the treatment of arteriovenous malformations (AVMs) and focal epileptic lesions, comprising administering to a patient in need thereof accelerated ions from an accelerator complex according to claim 1 , wherein a three-dimensional feedback system is foreseen to treat the patient without unwanted irradiation of the tissues that need to be spared.
11. An accelerator complex ( 12 ) comprising:
an ion source ( 1 ) configured for producing beam pulses of ions with an atomic number between 1 (protons) and 10 (neon ions),
a pre-accelerator ( 3 ) configured for accelerating rates of the beam pulses,
a high-energy section ( 13 ) configured to receive beam pulses from the pre-accelerator ( 3 ), the high-energy section ( 13 ) containing at least one 3 GHz linac ( 5 ; 6 ; 7 ) that is configured to accelerate 4He2+ ions of beam pulses produced by said ion source ( 1 ) and to operate with the following parameters:
Frequency [MHz]
2998
Q (ion charge)
2
A (ion mass number)
4
Input energy [MeV/u]
60
Total input energy [MeV]
240
Maximum output energy [MeV/u]
160
Maximum total output energy [MeV]
640
Number of cells in an accelerating
18-16
structure (or tank)
Iris diameter [mm]
7
Number of units
10
Unit length [m]
0.75-1.05
Total length of the linac [m]
9.5
Average transit time factor T
0.85
Effective Shunt Impedance's = ZT2
53-77
[MΩ/m]
Average electric field on axis E0 [MV/m]
33
Maximum surface electric field [MV/m]
140
Transverse normalized acceptance at 2 rms
2.4
[π mm mrad]
Peak power per unit [MW]
10
RF Pulse duration [μs]
4
Repetition rate [Hz]
120
Fraction of time with beam (or duty cycle)
0.048
[%]
Average power to feed the 10 klystron [kW],
150
the high-energy section ( 13 ) being configured to vary energy of outgoing accelerated 4He2+ ions by acting on the radio frequencies sources of at least one linac ( 7 ), said outgoing accelerated 4He2+ ions of beam pulses forming a spot that delivers a dose of beam pulses to a target area of a patient's body,
a three-dimensional feedback system configured to vary, before sending every spot, two transverse positions and a depth in the patient's body so as to compensate for the movements of a targeted area such that the dose of beam pulses delivered by every spot is limited to a targeted area in order to reduce unwanted irradiation to non-targeted areas, and
a High Energy Beam Transport channel (HEBT) with an associated magnet system that transports the beam pulses forming every spot from the high-energy section ( 13 ) to a treatment room of said patient.