Device for irradiating a tumor tissue

Translation of description of equivalent WO 0207817 A2

Apparatus for irradiating tumor tissue

The invention relates to an apparatus and a method for irradiating tumor tissue of a patient by means of ion beam according to the independent claims.

The ion beam scanning and procedures as underlying for example the European patent application 98 117 256.2 newly developed, allow increased precision irradiation of deep-seated tumors.

With these devices and methods is the target volume, such as a tumor of a patient, separated into layers of the same reach, which are then scanned with an ion beam surface rasterför- mig. This ion beam is supplied with respect to a fixed coordinate system in a treatment chamber, wherein the solid angle of an ion beam axis is fixed in the irradiation chamber or can be discharged by means of a gantry from different spatial angles.

In order to position the tumor of a patient in this fixed coordinate system of the irradiation room, it is necessary to move the patient at the start in the correct set position with respect to this coordinate system, so that the actually irradiated and scanned volume of the ion beam coincides with the planned target volume of the tumor in the patient. In addition, it is necessary with these known systems that comply with the desired position of the patient during irradiation. To maintain the desired position elaborate facilities such as custom-made thermoplastic mask systems are used for fixing the patient to adjust the patient before irradiation with millimeter precision and immobilize during irradiation through the mask. With the known devices and methods therefore only spatially fixed target volumes can be irradiated, such as tumors in the head and neck area and tumors near the spinal column, in which either the head alone is fixed through an appropriate mask or a full body mask immobilize the spine.

An irradiation of moving target volumes, for example in the thoracic region is, with such a method not previously possible. For example, the target volume is moved in a thoracic area by a few centimeters by a respiratory movement, and thus the desired millimeter precision impossible. So it is impossible to achieve fixing with an accuracy of millimeters, when the same move internal movements, the target volume in the centimeter range. In addition, a movement of the target volume while scanning beam causes strong Dosisinhomogenitäten.

During the relatively fast, flat and raster-scanned could follow the lateral movements of the target volume in the centimeter range at a constant energy of the ions in the ion beam in time, the energy variation is by the accelerator not sufficiently fast to the body movements, for example by breathing or heartbeat in the thoracic region of a tumor patient to be able to follow in depth.

The object of the invention is to provide an apparatus and method for irradiating tumor tissue of a patient by means of ion beam, wherein the ion beam to the spatial and temporal change, in particular spatial and temporal periodic changes of the target volume, both perpendicular to the beam direction as well as in depth is adapted ,

This object is achieved by the subject matter of the independent claims. Features of preferred embodiments are defined in the dependent claims.

According to the invention, the device for irradiating tumor tissue of a patient by means of ion beam to a deflection direction of the ion beam for slice have Flächenabtasten of the tumor tissue and an accelerator having an ion beam energy control device for step-wise depth scanning of the ion beam. In addition, the apparatus includes an ion-braking device, which is used as a fenabtast animals adaptation device for adapting the range of the ion beam and a faster depth-wise adaptation than the energy control device of the accelerator. Furthermore, the device has a Bewegungserfas- detection device for detecting a temporal and positional change in the location of the tumor tissue in a treatment chamber and a control device which the deflection device and the depth-wise scanning adaptation apparatus for tracking the lonenstrahlrichtung or lonenstrahlreichweite during scanning of the tumor tissue under temporal and spatial change in position of the tumor tissue in the treatment space controls. The inventive device has the advantage that moving target volumes of a moving patient can be irradiated in a fixed patient with the same precision as unmoving target volumes. Given detects the Bewegungserfas- detection device the movements of the patient during radiation and the irradiation points are corrected by means of the control device. In principle unnecessary in this device also an initial extremely exact adjustment of the patient in the space-fixed coordinates because using the motion sensing device adapted the actual start position of a patient to the irradiation program or the irradiation program can be corrected accordingly.

In a preferred embodiment of the invention, the apparatus comprises two electromagnets, with which the deflection device enables a planar scanning. These electromagnets direct the beam perpendicular to the ion beam axis in an X and Y direction from which in turn are perpendicular to each other, to slice by slice to ensure a relative to the depth scanning quick means of ion beam energy control device planar scanning of the tumor tissue. For this purpose, the electromagnets are controlled by fast-reacting power supplies and measuring instruments. These devices can therefore also be used in order to achieve a correct and adjust the sampling of a tumor tissue be temporally and örtlicher- change in position of the tumor tissue in the treatment space orthogonal to the ion beam axis.

In a preferred embodiment of the invention, the device comprises at least one accelerator with which the energy of the ion beam is adjustable so that the tumor tissue is slice-wise staggered in depth irradiated. This has the advantage that one after the entire tumor tissue is scanned slice by slice, wherein from disk to disk, the range of the ion beam can be adjusted by changing the energy of the ion beam. The accelerator is for this purpose consists essentially of a synchrotron or a synchrocyclotron in which ions the same mass and energy can be gradually accelerated to higher energies. The power adjustment of the ion beam to predetermined ranges within the irradiation chamber or within the tumor volume can be adapted due to the complexity of the control functions for the accelerator is not so short, and with the required precision, that the movements of the tumor tissue or the patient can be followed automatically.

In a preferred embodiment of the invention, therefore, the depth-wise scanning adaptation apparatus on two wedge-shaped in cross section ion-braking plates, which cover the entire irradiation field of the ion beam and enable fast depth-wise in moving tumor tissue.

For this, the ion-braking plates are arranged on electromagnetically actuatable carriages in a preferred embodiment of the invention. The position of the wedge-shaped ion braking plates within milliseconds can be changed and therefore the occurring in an overlap area of the wedge-shaped braking plates Abbremsweges length of the ions are varied by the ion-braking plates with the aid of these electromagnetically actuatable carriages. For this purpose, the ion-braking plates overlap in the entire irradiation field of the ion beam and can thus independent of location, the ions in their range of spatial and temporal changes of a bew adapt egten target volume. In a preferred embodiment of the invention, the ion-braking plates are mounted on linear motors. Such linear motors have the advantage that a continuous fine regulation of Ionenabbremsung adapting depth scanning of the target volume is possible. Moreover, the adjustment of the position of the wedge-shaped ion braking plates by means of linear motors is not only locally highly accurate but also extremely responsive to temporal displacement of the target volume in the depth adaptable.

In a further embodiment, instead of the wedges, a water-filled cylinder whose thickness varied uses. The lid of the cylinder are made of transparent plates, z. B. of two plexiglass or quartz glass plates of which the upper disc is moved by 2 or 4 powerful linear motors. The side cover of the cylinder is realized by a bellows made of steel or rubber. The variation of the thickness of the water layer is supported by a hydraulic system which pumps into the pulling apart of the cylinder water into the cylinder and upon squeezing water out sucks, so that the drive is unloaded, the formation of vacuoles is prevented.

This disclosed embodiment has the advantage that a smaller minimum thickness than that of the wedges is possible. When the wedges, the minimum thickness calculated from Keil -Slope x field size (typically 5 cm). In the cylinder construction, the minimum thickness is determined by the thickness of the two covers (typically 1 cm). This low minimum thickness reduces to scattering of the beam, thus improving the beam quality. Furthermore the cylinder construction in the transverse direction is more compact than the wedge construction. In a further preferred embodiment of the invention, the movement detection device has at least two measuring transducers which nenstrahlachse from two spatial angles with respect to an ion the temporal and spatial location of markings on a, detect a body portion tumor tissue contained a patient. Such markings can be applied with skin-compatible fluorescent colors in the form of dots, lines or other geometric forms or as light-emitting elements to be clearly perceived and measured by the transducers.

In a further preferred embodiment of the invention, the measuring transducer precision video cameras, which cooperate with an image evaluation unit. This achieves the advantage that the movements of a body portion near a tumor tissue can be measured accurately and can be correlated with the temporal and spatial shifts in position of the tumor tissue.

Alternatively to the motion detection system using markings on the body surface and a precision video system, has a further embodiment of the invention on an X-ray system, which detects the movements of the tumor tissue directly in the body. This motion detection system, two X-ray tubes with beam direction orthogonal be attached to the ion beam. The two X-ray tubes in turn are also oriented perpendicular to each other. For this purpose, two respective opposite, sensitive on the other side of the patient X-ray image intensifier are mounted. The X-ray tubes emit short X-ray flashes with low power in order to keep the radiation dose low, with a frequency of eg 20 Hz. The associated X-ray images of recorded the image intensifiers and digitized. Characterized an image sequence for two directions is obtained, from which, using a suitable method and corresponding software, the displacement of the target points Pi in near real time at about 50 ms delay is determined.

This embodiment has the advantage that the X-rays much more information is obtained about the movements in the interior of the body than from external markers on the body surface. This allows a more precise determination of the temporal and spatial organ shifts.

In principle, the irradiation of the tumor volume of pixels is composed, which are flat against one set in a disk shape rasterfδr ig, wherein the ion beam from sample to sample is deflected perpendicular to its beam axis in an X and Y direction. If the energy of the ions can be held constant by the corresponding accelerator in an ion beam, yet the number of ions per unit volume point is not constant over time. In order nevertheless to irradiate an equal ion beam dose in each point of the volume of the tumor tissue, an ionization chamber is disposed with fast read-out for monitoring the intensity of the lonenstrahlstromes as a transmission counter in the beam path of the ion beam in a preferred embodiment of the invention. Such a transmission counter determines the residence time of the ion beam on a volume to be irradiated point of the tumor volume, and an associated control unit directs the ion beam from point to the next volume, as soon as a predetermined radiation dose is achieved. Thus, can be scanned in a grid-like planar manner advantageously a volume slice of a tumor volume. Preferably, the ionization chamber between the deflector and the Tiefenabtas -Anpassungsvorrichtung arranged especially as the depth-adjustment device with its wedge-shaped ion-braking plates or the water layer between transparent plates, only the ion controls within their reach, but does not affect the ion dose.

A method for irradiation of a tumor tissue of a patient by means of ion beam 'has the following method steps: positioning the patient on a patient contour matched device for placing the patient in an irradiation chamber,

Application of markings on a body area of ​​the patient near the tumor tissue,

Detecting the temporal and spatial change of the marks via a movement detecting means or detecting X-ray images of the tumor tissue of two mutually perpendicular directions of X-rays orthogonal to the ion beam,

Tracking of the ion beam during scanning of the tumor tissue with an ion beam deflector and an ion. | beam energy control device by means of an additional depth-wise scanning adaptation apparatus II, which adjusts the range ij \ of the ion beam to the detected by the motion detection means temporal and local changes of the markings in conjunction with the ion beam deflector.

With this method, it becomes possible in an advantageous manner, the same precision as in patients also fixed when moving patients in the millimeter range in the irradiation to achieve by moving tumor volumes, even if the tumor tissue up to several centimeters periodically, for example, moves by heartbeat or respiration air. Constantly the ion beam irradiation is followed by the temporal and spatial position shift of the tumor tissue, and it does not need to be awaited with the irradiation until a repetitive local position is reached. Also slow movements of the patient, which occur non-periodically, are permissible and can be adjusted using the depth adjustment device and the deflector in time and place in their ion irradiation. Only when sudden shifts in position as for coughing the irradiation process must be stopped.

Opposite procedures that allow only one irradiating upon reaching identical layers of the tumor tissue, the inventive method has the advantage that the irradiation time of a patient can be substantially reduced because of the irradiation sequence is not, for example, depending on the frequency of the heartbeat or the breathing of a patient.

Further advantages and features of the present invention will now be explained in more detail by way of embodiments with reference to the accompanying drawings.

Fig. 1 shows a schematic diagram of one embodiment of the invention under irradiation of a tumor tissue in the thoracic region of a patient.

Fig. 2 shows a schematic diagram of an embodiment of a motion detection device. Fig. 3 shows a comparison between adjacent Volumenabtastpunkten in place and time fixed and therefore static target volume and spatially and temporally moving and thus dynamic target volume.

Fig. 4 shows a schematic diagram of one embodiment of the invention under irradiation of a tumor tissue in the head region of a patient.

Fig. 5 shows a schematic diagram of a Ionenbre-measuring device by means of a variable water volume.

Fig. Figure 6 shows a schematic diagram of a further embodiment of the invention under irradiation of the tumor tissue in the head region of a patient.

Fig. 1 shows a schematic diagram of one embodiment of the invention under irradiation of a tumor tissue 3 in the thoracic region 23 of a patient 10. For this purpose, the device comprises an ion beam 2, the beam axis from its Ionenstrahlach.se 15 by an ion beam deflector 1 orthogonal to the ion 15 is deflected, in an X direction while passing through a gap 24 of an electromagnet 13 and in the Y direction while passing through a gap 25 of an electromagnet 14, wherein the column are perpendicular to each other.

The ion beam further passes before impinging on the tumor tissue 3 of a patient an electromagnetically in the arrow direction R driven ion-braking device 11, 12, which is used as a depth-adjustment device 5 for adjusting the range of the ion beam 2 and a faster depth-wise adaptation as a has not shown power control means, with which the energy of the ion beam before entering into the gaps 24, 25 of the electromagnets 13 and 14 is controlled.

The ion beam energy control device, not shown, causes a graduated depth scanning of the tumor tissue 3, wherein penetrates by gradually increasing the energy of the ion beam in each case by a disk wise area sampling deeper in the tumor tissue, so that eventually the whole tumor tissue is destroyed by slice-wise depth scanning of the ion beam.

Upon movement of the outlined here patient 10 in a position which is marked with dashed line, also the location of the tumor tissue 3 shifts, so that with a static radiation that can not follow the patient's movement, healthy tissue would be irradiated and destroyed.

To avoid this, the device in Fig. 1 is a movement detection device 7 for detecting a temporal and positional change in the location of the tumor tissue in a treatment room 3 to 8. These motion detection means 7 consisting in this embodiment of the invention consists of two precision video cameras 21 and 22 tracks the movement of marks on a body area of ​​the patient 10 and communicates with an image evaluating device connected which of the detected change values ​​of the marks with the temporal and positional change Location of the tumor tissue 3 correlated.

A not shown in FIG. 1, control means controls both the deflection device 1 with the two electromagnets 13 and 14 and the depth-wise Anspassungsvorrichtung with the ion-braking device 11, 12 for tracking on the one hand the lonenstrahlrichtung and secondly the lonenstrahlreichweite during scanning of the tumor tissue under temporal and spatial change in position of the tumor tissue 3 in the treatment chamber 8. With the device shown in FIG. 1 is a higher precision of the beam application and thus an improved clinical success in the more than hundred-year history of the development of scored radiotherapy.

The continued increase in precision has led to the use of this scanning system consists of two perpendicularly arranged electromagnets, by their magnetic gaps, an ion beam is guided and deflected. In applying the device according to Fig. 1, the target volume, namely the tumor tissue 3, scanned with a fine stream of ions to variable intensity. The diameter of the ion beam is in the millimeter range and the precision with which the target volume with an ion dose may be occupied, is also within the range of a few millimeters.

With a displacement of the target volume 26 during irradiation there is a deviation between the actual beam focus and the current target point and thus to incorrect irradiation inside the target volume 26. In order for a local underdosing or overdosing is connected. Therefore scanning methods can be used without the inventive device of FIG. 1 at present with moving target volumes 26 not.

Other irradiator work with strongly widened beam and with an equally strong-spread maximum dose in depth. Such widened beam of rays can all target volume without area scan disk as capture and due to the large irradiation field do not generate DosisInhomogenitäten in the interior of the target volume, as with the use of disk-point scanning of the case when the target volume would be moved. The movement of organs affects at devices flare-ray beam just at the edge and can therefore be compensated for by an increase in the irradiation volume, so that no longer rely moving parts of the target irradiation volume. However, this in turn means that a wide range of healthy normal tissue at the edge of the target volume to be mitbestrahlt so that a reduced precision and simultaneously increased negative side effects for the patients are the result of an expanded bundle of rays with simultaneous movement of the irradiated body.

With a device, as shown in Fig. 1, but without a depth-wise scanning adaptation apparatus 5, organ movements can only be considered if the cross section of the ion beam 2 is considerably increased. Such a solution, however, also means a reduction in the precision in the lateral region, and in the longitudinal dose profile is no correction takes, as a beam expanding the movement in the beam direction can not be corrected. Thus, still results in a beam expansion to cover the organ motion an inhomogeneous dose distribution of the internal target volume in the beam direction.

A further option, the apparatus of FIG. 1 without a depth-wise scanning adaptation apparatus to apply 5 and still take into account organ motion may be that 7 periodic movements by means of the movement detection means detects, for example, the thorax region of a patient and only then an irradiation is carried out when the thorax assumes identical positions. Such Vorrich- device in which no depth adjustment device is provided, however, is detected, the periodic movement of a thorax of a patient, would lengthen the irradiation or treatment period of a patient by a multiple, as for each volume point in the slice-wise scanning of the tumor volume at first the identical position the tumor is seen. Only a beam expansion can here reduce the treatment time in a realistic sizes, which in turn, as mentioned above, associated with a loss of precision.

Thus, the device of the invention proves to be the concept, optimal penetration depth of the ion beam can be adjusted to the body movements of a patient with, so that with high precision, a tumor tissue can be irradiated with millimeter precision in temporal and spatial change in position.

Fig. 2 shows a schematic diagram of an embodiment of a motion detection means 7. This embodiment detects the motion of a body region of a patient 10 by means of second precision video cameras 21 and 22, the marks 4 on the thorax of a patient 10 from two different

collect solid angles α and ß and perform an image evaluation unit not shown. The marks 4 are selected such that they are a part, is arranged in the vicinity of the tumor to be irradiated tissue and on the other hand grasp the thorax movements so accurate that on the temporal and spatial changes in the marks 4 can be closed to the temporal and spatial shifts in position of the tumor tissue.

The solid angle and ß point in the Cartesian coordinate system of the irradiation space 8 with the coordinate directions X, Y and Z components of solid angle α_x, α_y and _z α and ß for the solid angle_x, ß_y and ß_z for the solid angle ß on. With these components, the solid angle α and ß are clearly in the irradiation chamber 8 with the system of coordinates X, Y and Z are correlated.

The position of a first precision video camera 21 has in this case the projection points Aα, B_α and C_α , where the projection point A "the plane defined by the coordinates X and Z plane, the projection point B_α the spanned by the coordinates X and Y plane and the projection point C_α the spanned by the coordinates Y and Z plane pierces. The position of the second camera 22, the projection point A_ß, B_ß and C_ß , where the projection point A_ß the plane which is spanned by the X and Z coordinates, the projection point B_ß the plane which is spanned by the coordinates Y and X, and the projection point C_ß the plane which is spanned by the coordinates Y and Z, pierces. This projection points the position of the precision cameras 21 and 22 in the irradiation chamber 8 is also clearly defined, the coordinates of the spatial angle α of the first precision video camera 21 x_{α /} y_α and Z_α amount and the coordinates of the spatial angle ß with the position of the second precision video camera 1 X_ß, y_ß and Z_ß are.

The largest organ movements and thus the greatest temporal and spatial changes in the mark 4 result in a patient in the lungs during breathing. In mid-thoracic region 23 shifts with amplitudes of up to 1 cm and at the edge of the lung of up to 3 cm are found. These shifts by breathing periodically. The displacement of the internal structure is with the movements of body surface area correlated. Therefore provides visual monitoring and recording of the body surface by means of precision video cameras 21 and 22 respectively current location coordinates of the internal structures. This can be as light-emitting diodes mounted on the body surface as labels 4 strokes of color, color dots or light-emitting elements. Thus, advantageously without invasive intervention in the patient inside the geometry at any given time are detected, and thus a temporal course of the displacements of the internal structures, and the tumor tissue and the speed of the respective movements are detected.

Fig. 3 shows a comparison between adjacent Pi and Pi Volumenabtastpunkten_{+ ι} or P ' _{i + 1} in place and time fixed and therefore static target volume V_Ξ or spatially and temporally moving and thus dynamic target volume V ^. The detection of the movement of the internal structures in correlation to the surface must be known before the irradiation. This can result from model calculations or from measurements.

Is from a snapshot at the time t = 0 is considered so can similarly decomposes the target volume in layers having a depth coordinate Zi same particle range as in the raster scanning method for a non-moving object, and each layer with a lateral grid in X and Y direction for a short-time recording with reference pixels which Volumenabtastpunkten Pi coat (i, y i, z). During irradiation, these pixels are due to the movement in a position P'i (i + Δ i (t) + Δ yi yi (t) + Δ Zi zi (t)) shifted. The

Deviations or displacements .DELTA.x, Ay and Az arising from the three-dimensional velocity distribution of body movement in time .DELTA.t, the dose application of Vo- lu enpunktes P of the tumor tissue 3 is necessary. With a maximum lift of the thoracic region 23 of 3 cm and a respiratory rate of about 0.5 Hz, ie a period of 2 s, results for the body movements, for example, a speed<img id="imgf000020_0001" he="6" wi="60" file="imgf000020_0001.tif" img-format="tif" img-content="drawing" orientation="portrait" inline="yes" />

The pixels Pi, which are now to Volumenabtastpunkten, be at a lateral and longitudinal scanning method apart 1-3 mm, that is, after an irradiation dose at the point Pi of the next adjacent point in 1 to 3 mm distance Pi₊ι approached and re-introduced a radiation dose in this Volumenabtastpunkt. The time for applying the dose in a Volumenabtastpunkt Pi or Pi₊₁ is less than 10 ms. Consequently, the target point moves in this 10ms maximum of 0.3 mm, ie much less than the distance between two Volumenabtastpunkten Pi and Pi₊i. Since the currently irradiated Volumenabtastpunkt Pi moved during irradiation by less than the uncertainty of irradiation, it is not necessary to move the point Pi during each irradiation. After irradiation of the beam i have a point P'i₊i wander, of the originally planned point Pi₊i is removed in accordance with the coordinate movement of the organ. This body motion is in Fig. 3 and denoted by r is obtained from the speed v r =_0rgan -Δt. The actual position of the (i + l) th point is:

P 'i₊i = (xi + i + DELTA_{i + 1} (T), y_{i +}ι + Dy_{i +}ι (t), z_{i +}ι + Az_{i + 1} (T)).

The deviation or displacement of the moving points p'i of the originally static network Volumenabtastpunkte Pi results from the displacement during the exposure time. With the usual cyclical and periodic movements like Respiration, heart rate, etc. through these points also a cyclic curve, which can be correlated with the movement of the body surface. Therefore, a parameterization of the path over time is possible. Non-cyclical operations can be controlled by the inventive apparatus and the inventive method for irradiating tumor tissue of a patient by means of ion beam only if the movement does not occur spontaneously, but with a speed which is considerably slower than the scanning speed of the ion beam. With sudden quick movements, such as occur for example in a coughing fit, the device must be switched off at short notice in order to protect healthy tissue from incorrect dosing.

Fig. 4 shows a schematic diagram of one embodiment of the invention under irradiation of a tumor tissue 3 in the head 6 of a patient 10. The device of Fig. 4 substantially corresponds to the apparatus of Fig. 1 and also comprises two electromagnets 13 and 14 for deflecting the ion beam 2 from its axial direction 15, whereby the ion beam is controlled in its range by wedge-shaped in profile ion-braking plates 16 and 17th The overlapping areas 28 and 29 cover at least the entire irradiation region, by stacking closing of the wedge-shaped profiles of the braking plates 16 and 17 of the deceleration distance of the ion beam 2 by the braking plates 16 and 17 increases and thus the range of the ion beam is reduced. By moving apart of the wedge-shaped braking plates of the deceleration distance is reduced, thereby increasing the range of the ion beam.

The direction of movement of the wedge-shaped braking plates 16 and 17 is indicated by the arrows R in Fig. 4. The comparison displaceable braking plates with cuneiform profile are in driven this embodiment with a powerful linear motor, so that a bright intensive controlled depth adjustment can be performed. For the linear drive, the depth-wise scanning adaptation apparatus 5 to an electronic control system, which interacts with the movement detection unit 7 and the deflector first In order to ensure a quick reaction, the rotor of the linear motor, the braking plates 16 and 17 bears on a slide, air bearings, and the motor currents of the linear motor are controlled via a stepper motor controller.

Fig. 5 shows a schematic diagram of an ion-braking device 43 by means of a variable water volume. Components having the same functions as in the previous figures are identified by like reference numerals and are not explained.

Numeral 44 designates a water layer that is sandwiched between two transparent plates 31 and 32nd Of the transparent plates 31, 32, the plate 31 is moved by means of linear motors 34 and 35th The number of linear motors can be increased to increase the rate of displacement of the plate 31st The water layer 44 is laterally secured from leaking through a bellows 37th To trap or water to supplement depending on the direction of movement in the direction of arrows G and F the volume of water, a surge tank 36 is provided, the hydraulic linear motors 34 and 35 supported by the fact that in increasing the water layer 44 Add water pumped and when reducing the thickness of the water layer 44 water is sucked. Numeral 33 denotes the water-filled gap. The ion beam 2 is sent to the braking by the water layer 44 and must thereby can the transparent plates 31 and 32 which are made of glass or Plexiglas NEN, penetrate. The lowest deceleration is achieved when the two plates 31 and 32 lie on one another. Then, they also have an extremely small thickness, which minimizes the scattering of the ion beam.

Fig. Figure 6 shows a schematic diagram of a further embodiment of the invention under irradiation of a tumor tissue 3 in the head region of a patient. Components having the same functions as in the previous figures are identified with the same reference and are not discussed separately.

This further embodiment 4 6 differs from the embodiment of FIG. Characterized in that the ion deceleration device 43 is not the key system is used, but the braking device shown in Fig. 5 43. Moreover, 'differs further embodiment in Fig. Of the embodiments in Fig. 1 and Fig. 4 in that a system is used consisting of at least two X-ray tubes as a motion detection system. The transducer 19 and 20 are X-ray tubes 38 and 39 each directed X-rays at a right angle to the tumor tissue of the patient 3 10th These X-rays are directed from X-ray flashes with low power in a frequency of 20 Hz, for example on the tumor tissue and 40 and 41 received by corresponding image intensifier plates or sensor plates that pass their signals to the evaluation 42nd This motion detection system with X-rays can pursue directly inside the body movements of the tumor volume and therefore very precisely control the braking means 43rd

1. Implementing of the method In a first exemplary implementation of the process prior to irradiation, the surface of the patient is provided with significant markings such as color markers on the skin or light emitting diodes, etc .. The patient is with, for example, on a foam bed, as shown in FIG. 1 and FIG. 4 the reference number 30 can be seen, stored, adapted his body. This can be achieved without forced a bearing accuracy of about 1 cm. In the irradiation position, as shown in the figures, Fig. 1 and Fig. 4, the patient 10 is monitored α and ß with a precision video system of at least two precision video cameras 21 and 22 from different directions in space at angles in space, that the position of the marks 4 (see FIG. Create 2) record as a function of time and a time-dependent correction function of the pixels or Volumenabtastpunkte Pi '(t).

To obtain a rapid displacement of the ion beam 2 in three dimensions, the lateral intensity-controlled raster scanner of two electromagnets 13 and 14 is combined with a depth-wise scanning adaptation apparatus 5, since rapid power variation by an ion beam Energiesteuerein-direction during irradiation of a volume point P from no ion accelerator is possible here. The lateral scan part, which consists as mentioned above of two electromagnets whose deflection direction is perpendicular to each other and to the beam axis 15 is disposed is controlled by fast network devices, so that a rapid lateral Abtastanpassung is ensured in the X and Y direction.

In addition to the scanning device 1 in X- and Y-direction of an electromechanically operated depth-wise scanning adaptation apparatus is in front of the patient's disposed, which consists of two wedges substantially the opposite direction on a Linear motor are mounted and cover the entire irradiation field. This depth-wise scanning adaptation apparatus is only for correction of the depth position variation of the image points by movement of the patient or the patient's organs. This depth-adjusting device does not illuminate the entire depth of the target volume.

For coarse depth variation the energy variation of a synchrotron or other accelerator is used. Here, the beam current is monitored using an ionisation chamber installed in the beam path in front of the patient and of a Volumenabtastpunkt Pi to the next sampling point Pi₊i diverted if the necessary Teilchendosis per Volumenabtastpunkt P is reached. Simultaneously, the surface motion is measured and used to calculate the movement of the internal structures in the target volume in accordance with the precision video camera monitoring the patient.

Due to the migration of the target points in three dimensions, the magnetic values ​​of the bending magnets and the depth adjustment values ​​of the wedge-shaped braking plates are corrected. Since the beam in this type of method and apparatus is not interrupted during the irradiation, also no unirradiated sites found in tumor tissue. The precision in the interior and also the sharp edge drop a static irradiation is thus achieved for moving bodies under dynamic irradiation.

In addition, the apparatus and method is also invariable in relation to the compression volumes of doses. In a volume compression, for example in the lungs, the pixels come closer to each other are. Thus, the local fluence increases. At the same time by the compression also the bulk density increases. As the dose is defined as the energy deposition per density, it remains at a compression in a first approximation. This means that the particle motion of the individual beam positions during the irradiation with the inventive apparatus and the inventive method does not need to be corrected.

2. Implementing of the method

In a second implementation of the method, the temporal and spatial changes in the tumor tissue can be detected directly by X-rays than the mark on the patient's body. For this purpose, according to the orientation of the patient two X-rays are directed to the tumor tissue, which are arranged perpendicular to the ion beam 2, and deliver the short Rδntgenblitze at low power in order to keep the dose low burden on the patient. These flashes may be directed at a frequency of about 20 Hz on the tumor tissue. The X-ray directions are mutually offset by 90 °, and together they are orthogonal to the ion beam 2 is arranged. Using the Rδntgenstrahlblitze image intensifier plates are exposed, giving their signals to an evaluation unit 42, the evaluation unit 42 control the braking means 43rd The braking device 43 is in this second operation example of the invention, a water layer 33, whose thickness is varied and the transparent between two plates 31 and 32 is arranged. The rapid variation of the water layer thickness is effected by changing the gap 33 between the two transparent plates 31 and 32nd This displacement is 34 and 35 made of linear motors, wherein simultaneously a compensation vessel 36 provides for pressure equalization and volume equalization of the water. All other irradiation steps for the treatment of Tumorvo- lumens correspond to steps that have already been listed in the first operation example.

LIST OF REFERENCE NUMBERS

Ion beam deflector ion beam tumor tissue marker depth-adjusting device head area motion detection means treatment chamber ion beam energy control device patient, 12 ion-braking device electromagnet for X deflection electromagnet for Y deflection ion beam axis 17 ion braking plates, 20 two transducer, 22 two precision video cameras thoracic gap of the electromagnet 13 gap of the electromagnet 14 target volume edge of the lung, 29 overlapping ranges foam bed, 32 transparent panels gap, linear motors 35 Reservoirs bellows, 39 X-ray 40, 41 sensor plates

42 evaluation

43 ion deceleration device

44 water layer

V_s static target volume v_d dynamic target volume

P, Pi Volumenabtastpunkt

pi₊1 α to Pi adjacent Volumenabtastpunkt, ß solid angle α_x, Cy, α_z Components of the solid angle α ßx, Py, ßi. Components of the solid angle ß (/ y (x, z_α Coordinates of the solid angle α with the first camera position

XSS, YSS / z_ß Coordinates of the solid angle ß with the second camera position

&amp; Ar B.alpha; C_α Projection points on the planes

XZ (A_α); YX (B_α); ZY (C_α) The first would r apo siti on Aß, Bß, CSS projection points on the planes

XZ (ATE); YX (Bß) and ZY (CSS) of the second camera position