WO2012025261A1

WO2012025261A1 - Therapy device

Info

Publication number: WO2012025261A1
Application number: PCT/EP2011/057619
Authority: WO
Inventors: Oliver Heid
Original assignee: Siemens Aktiengesellschaft
Priority date: 2010-08-27
Filing date: 2011-05-11
Publication date: 2012-03-01
Also published as: DE102010035650A1

Abstract

The invention relates to a combined electron and X-ray therapy device. The therapy device comprises a beam head which can be rotated about an axis of rotation and in which an electron beam device for producing an electron beam field and an X-ray device for producing an X-ray field are located. In the operational state both beam fields can be directed onto a target volume, for example a patient's tumour. Both beam devices comprise a separate electron accelerator which is optimised for the particular mode of operation. The RF power required for operating the accelerator is provided by a common RF source which is connected to both accelerators via a diverter. Depending upon the mode of operation, the diverter guides the RF power provided onto the particular accelerator.

Description

Description The invention relates to a combined electron and X-ray therapy device.

Such combination therapy devices work either ent ^¬ neither in an operating mode "X-ray" or in an operating mode "electron irradiation". With the respectively selected out ^¬ beam is a target volume, eg., A tumor of a patient is irradiated.

As a rule, such a device has a single electron accelerator in the form of a linear accelerator. The electron beam brought to a certain final energy in the accelerator strikes a target in the "X-ray irradiation" operating mode. In the target, the electrons of the electron beam are decelerated, resulting in X-ray Bremsstrahlung, which can be used to irradiate the target volume. Behind the target is a collimator for superimposing the X-ray cone on the target volume or for adapting the beam field, i. essentially the cross-sectional shape of the respective beam, to the target volume.

In "electron beam irradiation" is the target outside the electron beam path, so that the electrons can impinge on the patient or on the Packaging Target ^¬ lumen unhindered. A collimation as in X-ray mode is usually not used. For electron ^¬ ne operation, an electron energy of about 20MeV is required ^¬ tigt, for X-ray operation only about 6MeV.

However, this known arrangement has several disadvantages:

The high electron energy for electron irradiation requires a long accelerator, which allows only relatively small beam currents, since, inter alia, with the length of the loading accelerate the loss of electrons of the electron ^¬ beam increases. A short accelerator path allows the generation of a higher beam current al ^¬ so with a constant particle source. Consequently, only a relatively low dose rate is available with simultaneously unnecessarily hard beam ^spectrum in the X-ray mode because of the relatively long accelerator ^path . In addition, the electrons lost in the long beam tube cause harmful scattered X-radiation.

In addition to the above-mentioned problem of the length of the accelerator alone, also affects problematic in that the dimensions of the overall system consisting of Accelerati ^¬ ger, Target and collimator are so large that a ro tation of the system to the patient, the precise for a and, in particular, tissue-sparing irradiation, such as is necessary in IMRT, is not possible. To solve this problem, the electron beam is deflected at the accelerator output, so that the accelerator can be arranged substantially parallel to the rotation axis of the system. However, the necessary for this deflection magnet leads to a significant increase in particular the weight and, to a lesser extent, the dimensions of the radiating head to be pivoted. It is therefore an object of the present invention to specify a therapy device which, in a compact design, is capable of generating X-ray and electron radiation, in particular for therapeutic purposes. This object is achieved by the inventions specified in the independent claims. Advantageous embodiments emerge from the dependent claims.

According to the invention a combined therapy device is proposed which has a combined accelerator device with two ge ^¬ separated accelerators, both of which are alignable isolated on the target volume. One of the accelerators is set up to operate in X-ray mode of Therapy device to generate X-rays. The other accelerator is set up to generate an electron beam in electron beam operation of the combination therapy device. Thus, a function separation of the two operating modes "X-ray operation" and "electron beam operation" is introduced at the functional level of the accelerator.

Characterized in that separate accelerators are used, can be dispensed with the described in the introductory combination therapy device be ^¬ complicated complex mechanism for swinging in and out of the target and the collimator for X-ray and electron beam operation. Furthermore, it is possible to use an optimally designed accelerator for the respective operating mode or type of radiation without having to compromise.

For X-ray operation is a first, relatively short accelerator with a strong beam current whose accelerated electron beam is directed to generate the X-ray radiation to the target. Between the target and the target volume is an adjustable collimator. The short design allows a high beam current with simultaneously low scattered X-radiation.

For electron beam operation, a second relatively long high energy accelerator is used. This ensures that the electrons can be accelerated to a sufficient for the intended purpose of energy, so that the penetration depth is suffi ^¬ accordingly high for therapeutic purposes into the tissue to reach the target volume.

The two blasting devices are arranged such that the beam fields which can be generated with them are aligned with a working region of the therapy device. The target to be irradiated ^¬ volume is placed in the work area, so that it is coverable by the beam fields of the two beam devices. in the Case of a therapy device with a rotatable about a rotation axis beam head, in which the two beam devices be ^¬ find the arrangement is set up such that the

Beam fields in each position of the jet head are aligned to the work area. The isocenter of the arrangement is therefore in the work area and ideally in the target volume.

Both the first and the second accelerator may be radially aligned, ie, the accelerator and the beam tubes or accelerator sections are aligned such that their longitudinal axis and the accelerated electron beam in them substantially to the isocenter of the combination therapy device aims, so that each generated radiation ^¬ ment without the use of a deflection intersects the axis of rotation of the combination therapy device at an angle of about 90 °.

Alternatively, the jet pipes or accelerator sections can also be aligned axially, ie largely parallel to the axis of rotation of the combination therapy device. In order to be granted slightest ^¬ th, that the radiation generated in each case meet in a suitable manner to the target volume, a deflector may be provided. In the case of the electron accelerator, this is a deflection magnet, with which the initially axial orientation of the electron beam is converted into a, for example, radial orientation.

In the case of the accelerator for generating the X-radiation, the target is arranged such that the X-ray radiation generated in the target by the braking of the accelerated electrons exits the target at the desired angle to the electron beam. In an alternative embodiment of the X-ray accelerator, a deflection magnet is arranged in the region of the output, which deflects the electrons leaving the accelerator, whereby the required X-ray radiation in the form of Bremsstrahlung is generated. Although it is basically not necessary to align both accelerators in the same way, ie both radially or axially, but this is appropriate for reasons of space. In particular, a rapid Diale orientation is appropriate for the electron accelerator since then can be dispensed with Umlenkmagne ^¬ th. The same applies to the X-ray accelerator since, in the case of axial alignment, the measures required to generate the X-ray radiation deflected toward the target impact the X-ray dose rate achievable in the target volume less than in the case of radial alignment.

In summary, the therapy device according to the invention thus has a combined accelerator device with which optionally an X-ray field X and / or a

E-beam field E can be generated. The

Accelerator device is located in a jet head of the therapy device. The beam field generated in each case in the operating state can be aligned to a working area of the therapy device. The accelerator device includes

X-ray device for generating the X-ray field and an electron beam device for generating the

Electron beam field on. The X-ray apparatus comprises a first electron source, particularly an electron gun, a first electron ^¬ accelerator, and a target, wherein the removable of the first electron source, electrons are accelerated to the first electron accelerator in the operating state and the first electron beam thus generated to the target is court ^¬ tet, such that an X-ray radiation forming the X-ray field emerges from the target.

The x-ray apparatus further includes an adjustable collimator disposed between the target and the work area. The electron beam device includes a second electron source, particularly an electron gun, and a second Elect ^¬ Ronen accelerator, wherein the removable of the second electron source are accelerated by the second electron accelerator in the operating state and the second electron beam thus generated forms the electron beam field.

Furthermore, the electron beam apparatus, a Ablenkeinrich- tung, with which the electron beam is deflected selectively, so that an effective electron field can be generated whose cross-section is larger than the cross section of the Elect ^¬ Ronen beam. In a first embodiment, a first high-frequency source and SpeI ^¬ solution of the second electron accelerator are connected to the high-frequency power required for operation is provided a second high frequency source for supplying the first electron accelerator with the required for the operation of high-frequency energy ^¬.

In an alternative embodiment, the first and second electron accelerators are fed from a common high frequency source.

In this case, a high-frequency switch is provided, which is connected between the high-frequency source and the electron accelerator and which, depending on the selected operating mode of the therapy device, feeds the first or the second electron accelerator with the high-frequency energy provided by the high-frequency source.

The jet head with the accelerator device is advantageously rotatable about an axis of rotation. This ensures that the target volume can be irradiated under ideal conditions without the patient having to be relocated between two irradiations. Further advantages, features and details of the invention will become apparent from the ^exemplary embodiment described below and from the drawings. Showing:

FIG. 1 shows a combination therapy device in a first ^embodiment , FIG. 2 shows the combination therapy device in a second embodiment

Embodiment.

In the figures, identical or corresponding areas, components or component groups are identified by the same reference numerals.

1 shows schematically an inventive Kombina ^¬ tion therapy device 1 with a rotatable about a rotational axis R-jet head 10. In the ejection head 10 is an X-ray generating apparatus 100 of a Röntgenstrahlfel- of X and an electron beam device 200 for generating an electron beam field E.

With the aid of the devices 100, 200 and the beam fields E, X that can be generated with them, a target volume 310, for example a tumor of a patient 300, can be irradiated. The patient 300 or the target volume 310 is positioned in such a way that the target volume 310 lies in a working area A of the therapy device 1, which can be covered by the beam fields E, R.

The axis of rotation R of the jet head 10 is in the example shown here ge ^¬ perpendicular to the plane of the paper. The Zielvolu ^¬ men 310 may be, for example, positioned so that the Rotati ^¬ onsachse R intersects the target volume.

In the x-ray apparatus 100, x-ray radiation is generated in a manner known per se by irradiation of a target 110 with an electron beam 120. The required for this high-energy electrons are taken from an electron gun 130 and accelerated by means of a linear accelerator 140, which has a plurality of cavities 141-144, to the required energy, for example 6 MeV. The electron beam generated in the accelerator 140 120 leaves the accelerator through a vacuum window 150. In the target 110, the electrons of the electron beam 120 to be braked, said to he ^¬ generating X-rays X is formed. The X-radiation or its central ray X ₀ leaves the target substantially in the propagation direction of the electron beam 120.

Between the target volume 310 and the target 110 is for

Beam shaping of the X-ray beam X or to adapt the X-ray field X to the shape of the target volume 310, a collimator 160 is provided. This can be moved in the directions indicated by the arrows 161, 162 directions. The collimator 160 may, for example, be designed as a multi-leaf collimator, the lamellae of which are displaceable in the direction of the arrows 161, 162. With such a multi-leaf collimator 160, a comparatively detailed beam field adaptation is possible.

The electron beam device 200 also includes an electric ^¬ nenquelle 230 in the form of an electron gun and an electron accelerator linearly 240 with a plurality of cavities 241- 249th The electrons from the electron source 230 are accelerated by the electron accelerator 240 in a known manner and thus ge ^¬ introduced to an energy of, for example, 20 meV. This energy is sufficient to achieve a target volume in a typical of radiation depth in a size North ^¬ voltage of several cm in the tissue.

The electron beam 220 generated in the accelerator 240 leaves the accelerator through a vacuum window 250 and thus forms the electron beam field E. The electron beam field E in this case therefore consists only of the electron beam 220 leaving the accelerator 240. In the operating state, the electron beam field E is aligned with the target volume 310, ie on the tumor. A device 260 can be provided between the vacuum window 250 and the target volume 310, with which the electron beam 220 can be deflected in a targeted manner so that a target volume 310 can also be completely irradiated whose dimensions are greater than the diameter or the cross section of the electron beam 220 In other words, the effective diameter or the cross section of the electron beam field E can be increased by means of appropriate means relative to the diameter of the electron beam 220 leaving the accelerator 240. The device 260 may be configured, for example, to generate an electric and / or magnetic field with which the beam 220 can be deflected in one or two directions perpendicular to the beam direction. For this purpose, a control device 400 is provided, which is connected to the deflection device 260 (not shown) and, for example, using ei ^¬ nes irradiation plan, the deflection 260 so on ^¬ controls that the electron beam 220 is deflected so that the target volume 310 during an irradiation phase , ie in a certain position of the blasting head 10, is largely completely irradiated. The cross section of the electron beam field E then no longer corresponds only to the cross section of the electron beam 220, but rather to the region which can be scanned or scanned with the electron beam 220 with the aid of the deflection device 260.

In the exemplary embodiment illustrated in FIG. 1, it is provided that the X-ray apparatus 100 and the electron beam apparatus 200 are used alternately, ie not simultaneously. The supply of the two accelerators 140, 240 with the required for accelerating the electrons high-frequency energy is therefore possible with a single, shared high frequency source 11, which is controlled by the control device 400 depending on the desired mode of the therapy device. For this purpose, between the HF source 11 and the two electron accelerators 140, 240 a high-frequency switch 12 is connected, which is also controlled by the control unit. 400 feeds the electron accelerator 140 of the X-ray device 100 or the electron accelerator 240 of the electron beam device 200 with the high-frequency energy provided by the RF source 11. For this purpose, the source 11 with the switch 12 and the switch 12 with the accelerators 140, 240 via microwave waveguide 13 are connected.

The HF source 11 may be formed, for example, as a magnetron or as a klystron.

In an alternative embodiment shown in FIG. 2, it is possible to simultaneously operate the X-ray apparatus 100 and the electron beam apparatus 200. In this case, two separate RF sources 11, 11 'are required, but the switch 12 can be dispensed with. The HF sources 11, 11 'are connected to the accelerators 140, 240 substantially directly via microwave waveguides 13, 13'. In the figure 2 for clarity only the parent component of the therapy device with Be ^¬ reference numbers are provided.

In an embodiment not shown, one of the accelerator is at least not as in Figures 1 and 2 ra- dial aligned but axially, ie substantially paral lel ^¬ to the rotation axis R of the therapy device. In this case, additional means are needed with which the beam ^{generated in} each case can be deflected to the target volume. Such means are known. For example. In the case of the electron beam device, a device for generating a magnetic field could be used with which the electrons leaving the accelerator can be deflected from their original trajectory.

Claims

claims

1. therapy device (1) with a combined

Accelerator device, with the optional one

X-ray field (X) and / or an electron beam field (E) can be generated, wherein the accelerator device is in a beam head (10) of the therapy device (1) and wherein the respectively generated in the operating state beam field on a work area (A) of the therapy device (1) is alignable,

characterized in that

the accelerator device comprises an X-ray device (100) for generating the X-ray field (X) and a

Electron beam device (200) for generating the

Electron beam field (E) has.

2. Therapy device according to claim 1, characterized in that the X-ray device (100) has a first electron source (130), in particular an electron gun, a first

Electron accelerator (140) and a target (110) has ^¬ , wherein in the operating state of the first electron ^¬ source (130) removable electrons with the first electron accelerator (140) are accelerated and the so ^¬ generated first electron beam (120) on the Target (110) is directed, so that from the target (110) emits a X-ray field (X) forming X-ray radiation.

3. Therapy device according to claim 2, characterized in that the X-ray device (100) has an adjustable collimator (160) which is arranged between the target (110) and the working area (A).

4. Therapy device according to one of the preceding claims, characterized in that the electron beam device (200) has a second electron source (230), in particular a Elekt ^¬ ronenkanone, and a second electron accelerator (240), wherein in the operating state of the second electron ^¬ nenquelle ( 230) removable electrons with the second Accelerator (240) are accelerated and wherein the second electron beam (220) thus generated forms the electron beam field (E).

5. Therapy device according to claim 4, characterized in that the electron beam device (200) has a deflection device (260), with which the electron beam (220) is selectively deflected, so that an effective electron beam field (E) can be generated, whose cross section is greater than the cross section of the electron beam (220).

6. Therapy device according to one of claims 2 or 3 and one of claims 4 or 5, characterized in that for feeding the first electron accelerator (140) with the radio frequency energy required for operation, a first high ^¬ frequency source (11) and for feeding the second electron ^¬ accelerator (240) with the Hochfre ^¬ frequency energy required for operation a second high frequency source (11 ') are provided.

7. Therapy device according to one of claims 2 or 3 and one of claims 4 or 5, characterized in that the Ers ^¬ te (140) and the second electron accelerator (240) from egg ^¬ ner common high-frequency source (11) are fed.

8. Therapy appliance according to claim 7, characterized in that a high-frequency switch (12) is provided which interim ^¬ rule, the high frequency source (11) and the Elektronenbeschleu ^¬ niger (140, 240) is connected and the triebsart depending on the chosen loading of the therapy device (1) feeding the first (140) or second electron accelerator (240) with the high frequency power provided by the high frequency source (11).

9. Therapy device according to one of the preceding claims, ^¬ characterized in that the jet head (10) with the Be ^{¬ accelerator} device about an axis of rotation (R) is rotatable.

10. Therapy device according to one of the preceding claims, characterized in that the X-ray device (100) is aligned ra dial.

11. Therapy device according to one of claims 1 to 9, characterized in that the electron beam device (200) is radially aligned.