US20050139787A1 - Particle therapy system - Google Patents

Abstract

A particle therapy system capable of increasing the number of patients treated in one treatment room per unit time. The particle therapy system comprises a charged particle beam generator for generating an ion beam, an irradiation apparatus for irradiating the ion beam extracted from the charged particle beam generator to an irradiation target, a beam transport system for transporting the ion beam extracted from the charged particle beam generator to the irradiation apparatus, and a central control unit for producing a set of command data to command excitation currents for magnets disposed in the charged particle beam generator and the beam transport system, the set of command data being classified into group-1 data and group-2 data.

Description

BACKGROUND OF THE INVENTION
• 1. Field of the Invention
• The present invention relates to a particle therapy system, and more particularly to a particle therapy system for irradiating a charged particle beam, such as a proton or carbon ion beam, to a diseased part for treatment.
• 2. Description of the Related Art
• There is known a therapy method of irradiating a charged particle beam, such as a proton beam, to a diseased part, e.g., a cancer, in the body of a patient. A large-scaled one of therapy systems used for practicing such a therapy method conventionally comprises a charged particle beam generator, a beam transport system, and a plurality of treatment rooms. The charged particle beam accelerated by the charged particle beam generator reaches an irradiation apparatus in each treatment room through the beam transport system, and it is irradiated to the diseased part in the patient body from a nozzle of the irradiation apparatus. For that purpose, the beam transport system comprises a first beam transport system as one common system and a plurality of beam transport systems branched from the one first beam transport system and led to the respective irradiation apparatuses in the plurality of treatment rooms. At a position where each of the branched beam transport systems is branched, a switching magnet is disposed to bend the charged particle beam from the first beam transport system to be introduced to the corresponding branched beam transport system (see, e.g., Patent Reference 1: JP, A 11-501232 (pp. 12-13,FIGS. 1 and 2).
SUMMARY OF THE INVENTION
• Generally, a therapy system having a plurality of treatment rooms is operated by repeating each cycle comprising the steps of performing a setup in each treatment room, such as positioning of a patient, outputting a command value signal from a control unit to each of magnets disposed in a charged particle beam generator and a beam transport system when the beam is requested from the treatment room (or treatment control room) in which the setup has completed, to thereby perform beam setting and form a beam transport path led to the relevant treatment room, and irradiating the beam to the patient. During a period in which the beam setting and irradiation are performed in one treatment room, a next treatment room completes a setup and comes into a standby state. Therefore, as soon as the irradiation has completed in one treatment room, the beam setting and the formation of the beam transport path for the next treatment room can be performed at once. This means that if the beam setting takes a long time, a standby time is prolonged and treatment efficiency lowers. For that reason, a beam setting time is preferably as short as possible.
• In the known particle therapy system, though not specifically described in the above-citedPatent Reference 1, it is usual that various command values (hereinafter referred to as a “command value group”) outputted from the control unit to the respective magnets are simply stored in entirety, as they are, for each beam type. The term “beam type” used herein represents each type of beam defined in accordance with parameters, such as beam energy, intensity, a beam extraction destination (e.g., treatment room No.), and an angle of a rotating gantry. As a recent tendency, the number of types of required beams increases with a more variety of tumors. Assuming that the parameters for defining the beam types include, for example, 400 levels of energy, 10 levels of intensity, 4 kinds of beam extraction destinations (i.e., four treatment rooms), and 720 rotation angles of a rotating gantry (corresponding to 360 angles in units of 0.5 degree), 400×10×4×720=11,520,000 kinds of command value groups must be stored in total.
• The necessity of handling such a very large number of command value groups accompanies with a problem as follows. In the beam setting step, the control unit takes a relatively long time to search for, from among the very large number of command value groups, a particular command value group corresponding to the beam requested from the treatment room, and hence a time required for the beam setting is prolonged. Accordingly, treatment efficiency lowers and the number of patients treated in each treatment room per unit time reduces.
• With the view of overcoming the problems in the related art, it is an object of the present invention to provide a particle therapy system capable of increasing the number of patients treated in one treatment room per unit time.
• To achieve the above object, one feature of the present invention resides in producing a group of command values to command excitation currents for magnets disposed in a charged particle beam generator and a beam transport system for transporting a charged particle beam extracted from the charged particle beam generator to an irradiation apparatus, the group of command values being classified into a first command value group and a second command value group. With this feature, by employing the second command value group to command the excitation currents for steering magnets disposed in a gantry transport system and employing the first command value group to command the excitation currents for other magnets, for example, the first command value group in the whole of the command value group can be used in common when only a rotating gantry angle among parameters specifying the beam type is different, because the first command value group does not depend on the rotating gantry angle. Accordingly, the number of the command value groups to be stored can be greatly reduced in comparison with the known system in which the command value groups for the respective magnets are all simply stored as they are, and a search time required for specifying the necessary command value group from among the stored command value groups can be cut. As a result, it is possible to shorten a beam setting time in a control unit, and to increase the number of patients treated in one treatment room per unit time.
• Another feature of the present invention resides in further comprising an angle development computing unit for computing the second command value group depending on the rotation angle of the rotating gantry. With this feature, when the operator prepares one command value group at a certain level of beam energy, for example, by adjusting command values while actually irradiating the charged particle beam at a certain rotating gantry angle, the second command value group corresponding to the other rotating gantry angles (in units of, e.g., 0.5 degree) at that beam energy level can be automatically computed based on the command value group prepared through the adjustment. By computing and preparing the command value groups depending on the rotating gantry angle in such a way, whatever rotating gantry angle is requested from the treatment room, the beam transport system can be set up in response to the request, and hence a beam automatically settable range of the control unit can be greatly enlarged.
• Still another feature of the present invention resides in further comprising an energy development computing unit for computing the first and second command value groups depending on energy of the charged particle beam extracted from the charged particle beam generator. With this feature, when an operator prepares one command value group at a certain rotating gantry angle, for example, by adjusting command values while actually irradiating the charged particle beam at a certain level of beam energy, the first and second command value groups corresponding to the other levels of beam energy (in units of, e.g., 0.5 MeV) at that rotating gantry angle can be automatically computed based on the command value group prepared through the adjustment. By computing and preparing the command value groups depending on the beam energy in such a way, whatever beam energy is requested from the treatment room, the beam transport system can be set up in response to the request, and hence a beam automatically settable range of the control unit can be greatly enlarged.
• Still another feature of the present invention resides in further comprising an index information storing unit for storing index information to make the first command value group and the second command value group correspondent to each other, and a reading unit for reading the first command value group and the second command value group, which are made correspondent to each other, by using the index information. With this feature, the operator can specify the required command value group by using only the index information without being aware of the fact that the command value groups are classified into two groups, and convenience in handling of data can be improved. Further, the first command value group and the second command value group can be avoided from being read in a false combination.
• Thus, according to the present invention, the number of patients treated in each treatment room per unit time can be increased.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a conceptual diagram showing an overall schematic construction of a particle therapy system according to one embodiment of the present invention;
• FIG. 2 is a conceptual plan view showing a detailed construction of one of treatment rooms shown inFIG. 1;
• FIG. 3 is a block diagram showing a control system in the particle therapy system according to one embodiment of the present invention;
• FIG. 4 is a table showing one example of treatment planning data per patient;
• FIG. 5 shows a power supply control table previously stored in a disk disposed in a central control unit;
• FIG. 6 is a functional block diagram showing those ones of the functions of the central control unit which are related to a process for storing control command data;
• FIG. 7 is an illustration showing one example of index data displayed on a console display;
• FIG. 8 is a flowchart showing a flow of the process for storing the control command data to prepare the power supply control table in the disk disposed in the central control unit;
• FIG. 9 is a table showing one example of control command data newly computed in a gantry angle development processing unit by using a gantry angle development algorithm;
• FIG. 10 is a table showing one example of control command data newly computed in an energy development processing unit by using an energy development algorithm; and
• FIG. 11 a time chart showing a flow of the operation and control over time in the particle therapy system according to one embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
• A particle therapy system, as one preferable embodiment of the present invention, will be described below with reference to the drawings.
• As shown inFIG. 1, a particle therapy system of this embodiment comprises a chargedparticle beam generator1, fourtreatment rooms2A,2B,2C and3, a beam transport system made up of a first beam transport system (beam transport system in claims)4 connected to the downstream side of the chargedparticle beam generator1 and second beam transport systems (beam transport system in claims)5A,5B,5C and5D branched from the first beam transport system4, and switchingmagnets6A,6B and6C. The first beam transport system4 serves as a common beam transport system for introducing an ion beam to each of the secondbeam transport systems5A,5B,5C and5D.
• The chargedparticle beam generator1 comprises an ion source (not shown), a pre-stage charged particle beam generator (linac)11, and asynchrotron12. Ions (e.g., proton or carbon ions) generated from the ion source are accelerated by the pre-stage charged particle beam generator (e.g., a linear charged particle beam generator)11. An ion beam (proton beam) emitted from the pre-stage chargedparticle beam generator11 enters thesynchrotron12 throughquadrupole magnets9 and abending magnet10. The ion beam in the form of a charged particle beam (corpuscular beam) is accelerated in thesynchrotron12 in which energy is given to the ion beam with radio-frequency (RF) power applied from an RF cavity (not shown). After energy of the ion beam circulating in thesynchrotron12 has been increased up to a setting level (e.g., 100 to 200 MeV), an RF wave is applied to the circulating ion beam from an RF knockout electrode (not shown) for beam extraction. With the application of the RF wave, the ion beam circulating within a separatrix is forced to transit to the outside of the separatrix and to exit from thesynchrotron12 through a beam extraction deflector (not shown). At the time of extracting the ion beam, currents supplied to magnets, such asquadrupole magnets13 and bendingmagnets14, disposed in thesynchrotron12 are held at setting values, and therefore the separatrix is also held substantially constant. The extraction of the ion beam from thesynchrotron12 is stopped by ceasing the application of the RF power to the RF knockout electrode.
• The ion beam extracted from thesynchrotron12 is transported to the downstream side through the first beam transport system4. The first beam transport system4 has abeam line61 and includes aquadrupole magnet18, abending magnet17, anotherquadrupole magnet18, aswitching magnet6A, aquadrupole magnet19, aswitching magnet6B, aquadrupole magnet20, and aswitching magnet6C which are successively arranged on thebeam line61 in this order from the upstream side in the direction of beam advance. The ion beam introduced to the first beam transport system4 is selectively introduced to one of the secondbeam transport systems5A,5B,5C and5D depending on the presence or absence of a bending action provided in accordance with switching between excitation and non-excitation of those quadrupole and bending magnets and the switchingmagnets6A,6B and6C. Each of the switching magnets is one type of bending magnet.
• The secondbeam transport system5A has abeam line62 connected at one end to thebeam line61 and at the other end to anirradiation apparatus15A disposed within thetreatment room2A, and it includes abending magnet21A, aquadrupole magnet22A, abending magnet23A, a steering magnet7HA, a steering magnet7VA, aquadrupole magnet24A, a steering magnet8HA, a steering magnet8VA, abending magnet25A, and abending magnet26A which are successively arranged on thebeam line62 in this order from the upstream side in the direction of beam advance. The steering magnets7HA,7VA,8HA and8VA are magnets for adjusting the position of the ion beam. Among them, the steering magnets7HA,8HA adjust the position of the ion beam in the horizontal direction, while the steering magnets7VA,8VA adjust the position of the ion beam in the vertical direction. The steering magnets7HA,7VA,8HA and8VA are disposed in a part (gantry transport system) of the secondbeam transport system5A which locates within thetreatment room2A.
• The secondbeam transport system5B has abeam line63 connected at one end to thebeam line61 and at the other end to anirradiation apparatus15B disposed within thetreatment room2B, and it includes abending magnet21B, aquadrupole magnet22B, abending magnet23B, a steering magnet7HB, a steering magnet7VB, aquadrupole magnet24B, a steering magnet8HB, a steering magnet8VB, abending magnet25B, and abending magnet26B which are successively arranged on thebeam line63 in this order from the upstream side in the direction of beam advance. The steering magnets7HB,7VB,8HB and8VB are similar to the steering magnets7HA,7VA,8HA and8VA in the secondbeam transport system5A.
• The secondbeam transport system5C has abeam line64 connected at one end to thebeam line61 and at the other end to anirradiation apparatus15C disposed within thetreatment room2C, and it includes abending magnet21C, aquadrupole magnet22C, abending magnet23C, a steering magnet7HC, a steering magnet7VC, aquadrupole magnet24C, a steering magnet8HC, a steering magnet8VC, abending magnet25C, and abending magnet26C which are successively arranged on thebeam line64 in this order from the upstream side in the direction of beam advance. The steering magnets7HC,7VC,8HC and8VC are similar to the steering magnets7HA,7VA,8HA and8VA in the secondbeam transport system5A.
• The secondbeam transport system5D has abeam line65 connected at one end to thebeam line61 and at the other end to a fixedirradiation apparatus16 disposed within thetreatment room3, and it includesquadrupole magnets27,28 which are successively arranged on thebeam line65 in this order from the upstream side in the direction of beam advance.
• With the arrangement described above, the ion beam introduced to the secondbeam transport system5A is transported to theirradiation apparatus15A through thebeam line62 with excitation of the corresponding magnets. The ion beam introduced to the secondbeam transport system5B is transported to theirradiation apparatus15B through thebeam line63 with excitation of the corresponding magnets. The ion beam introduced to the secondbeam transport system5C is transported to theirradiation apparatus15C through thebeam line64 with excitation of the corresponding magnets. Also, the ion beam introduced to the secondbeam transport system5D is transported to theirradiation apparatus16 through thebeam line65 with excitation of the corresponding magnets.
• Thetreatment rooms2A to2C include respectively theirradiation apparatuses15A to15C each mounted to a rotating gantry (not shown) installed in the corresponding treatment room. Thetreatment rooms2A to2C are employed as, e.g., first to third treatment rooms for cancer patients, and thetreatment room3 is employed as a fourth treatment room for ocular treatment, which includes the fixedirradiation apparatus16.
• The construction and equipment layout in thetreatment room2A will be described below with reference toFIG. 2. Note that since thetreatment rooms2B,2C also have the same construction and equipment layout as those in thetreatment room2A, a description thereof is omitted here. Thetreatment room2A comprises a medical treatment room (compartment)31 formed in the first floor, and a gantry room (compartment)32 formed at a one step lower level, i.e., in the first basement. Further, anirradiation control room33 is formed outside thetreatment room2A in an adjacent relation to it. Theirradiation control room33 is similarly formed with respect to each of thetreatment rooms2B and2C. Theirradiation control room33 is isolated from both themedical treatment room31 and thegantry room32. However, the condition of a patient30A in themedical treatment room31 can be observed, for example, with a monitoring image taken by a TV camera (not shown) disposed in themedical treatment room31.
• An inverted U-shaped beam transport subsystem as a part of the secondbeam transport system5A and theirradiation apparatus15A are mounted to a substantially cylindricalrotating drum50 of the rotating gantry (not shown). Therotating drum50 is rotatable by a motor (not shown). A treatment gauge (not shown) is formed inside therotating drum50.
• Theirradiation apparatus15A comprises a casing (not shown) mounted to therotating drum50 and connected to the inverted U-shaped beam transport subsystem, and a snout (not shown) provided at the fore end of a nozzle through which the ion beam exits. The casing and the snout include, though not shown, a bending magnet, a scatterer device, a ring collimator, a patient collimator, a bolus (compensator), etc., which are arranged therein.
• The ion beam introduced to theirradiation apparatus15A in thetreatment room2A from the inverted U-shaped beam transport subsystem through thebeam line62 has an irradiation field that is roughly collimated by the ring collimator in theirradiation apparatus15A and is shaped by the patient collimator in match with the shape of a diseased part in the planar direction perpendicular to the direction of beam advance. Further, the ion beam has a penetration depth that is adjusted by the bolus in match with the maximum depth of the diseased part in the body of the patient30A lying on atreatment couch29A. Prior to irradiating the ion beam from theirradiation apparatus15A, thetreatment couch29A is moved by a couch driver (not shown) to enter the treatment gauge, and is precisely positioned in place for the start of irradiation from theirradiation apparatus15A. The ion beam thus formed by theirradiation apparatus15A so as to have a dose distribution optimum for particle therapy is irradiated to the diseased part (e.g., an area where a tumor or a cancer grows; hereinafter referred to as a “tumor”) in the body of thepatient30A. The energy of the irradiated ion beam is released in the tumor to form a high dose region. The travel of the ion beam in each of theother irradiation apparatuses15B,15C and the positioning of the treatment couch are performed in a similar manner to those in theirradiation unit15A.
• In this respect, therotating drum50 is rotated by controlling the motor rotation by agantry controller34. Also, the operation (energization) of the bending magnet, the scatterer device, the ring collimator, etc. in each of theirradiation apparatuses15A to15C is controlled by anirradiation nozzle controller35. Further, the operation of the couch driver is controlled by acouch controller36. Thesecontrollers34,35 and36 are all controlled by anirradiation controller40 disposed in thegantry room32 inside thetreatment room2A. Apendant41 is connected to theirradiation controller40 through a cable extended to the side of themedical treatment room31, and a doctor (or an operator) standing near thepatient30A transmits a control start signal and a control stop signal to thecontrollers34 to36 through theirradiation controller40 by manipulating thependant41. For example, when the control start signal for the rotating gantry is outputted from thependant41, a central control unit100 (described later) takes in angle information of the rotating gantry regarding the patient30A from treatment planning information stored in astorage110 and transmits the angle information to thecorresponding gantry controller34 through theirradiation controller40. Thegantry controller34 rotates the rotating gantry based on the gantry angle information.
• Anoperator console37 disposed in theirradiation control room33 includes asetup completion switch38 depressed by the operator when required setups, such as positioning of thetreatment couch29A, angle adjustment of the rotating gantry, and settings of various devices in theirradiation apparatus15A, have completed, adisplay39 for presenting display of a setup completion state on the mechanical side and index display (described later in detail), and anirradiation instruction switch42 depressed by the operator at the time of starting the beam irradiation. Theirradiation control room33 is likewise arranged for thetreatment room3 separately.
• A control system incorporated in the particle therapy system of this embodiment will be described below with reference toFIG. 3. Acontrol system90 comprises a central control unit (“control unit” in claims)100, astorage110 storing a treatment planning database, atreatment sequence controller120, a magnetpower supply controller130, a power supply unit for the accelerator (hereinafter referred to as an “accelerator power supply”)140, a power supply unit for the beam path magnets (hereinafter referred to as a “beam path power supply”)150, a power supply unit for the beam switching magnets (hereinafter referred to as an “beam switching power supply”)160, and apath switching controller170. Further, the particle therapy system of this embodiment includes aswitch panel180. Note that, although the construction of only one2A of thetreatment rooms2A to2C is shown inFIG. 3 for the sake of simplicity of the drawing, the other twotreatment rooms2B,2C are also similarly constructed.
• The treatment planning database stored in thestorage110 records and accumulates therein treatment planning data which has been prepared by doctors in advance for all the patients who will receive the irradiation treatment. One example of the treatment planning data (patient data) stored in thestorage110 for each patient will be described with reference toFIG. 4. The treatment planning data contains the patient ID number, irradiation dose (per one shot), irradiation energy, gantry angle, irradiation field size (not shown), irradiation position (not shown), etc. Although the treatment planning data contains the beam energy in the illustrated example, the beam energy may be calculated in thecentral control unit100 based on, e.g., range information because is the range information also contained in the treatment planning data.
• ACPU101 in thecentral control unit100 reads, from thestorage110, the treatment planning data regarding the patient who is going to take the irradiation treatment. Among the thus-read treatment planning data, the necessary data (such as the gantry angle, the irradiation field size, and the irradiation position) is outputted to the respective controllers (i.e., thegantry controller34, theirradiation nozzle controller35, and the couch controller36) via theirradiation controller40. Responsively, thegantry controller34 rotates the rotating gantry in accordance with the gantry angle information in the treatment planning data. Theirradiation nozzle controller35 performs settings of the bending magnet, the scatterer device, the ring collimator, etc. in theirradiation apparatus15A in accordance with the irradiation field size information, etc. in the treatment planning data. Further, thecouch controller36 performs positioning of thetreatment couch29A in accordance with the irradiation position information in the treatment planning data.
• When the patient comes into a state ready for the irradiation of the ion beam upon the completion of setups required prior to the irradiation, the operator goes out of thetreatment room2A, enters the correspondingirradiation control room33, and depresses the setup completion switch (or button)38 on theoperator console37. With the depression of thesetup completion switch38, a patient ready signal is generated and outputted to thetreatment sequence controller120.
• Thetreatment sequence controller120 sets the sequence of treatments to be performed in thetreatment rooms2A,2B,2C and3. The treatment sequence for the respective treatment rooms is decided in accordance with the sequence in which the patient ready signals have been inputted from the setup completion switches38 in theirradiation control rooms33 corresponding to thetreatment rooms2A-2C and3. The treatment room number having the top priority selected by the treatment sequence controller120 (i.e., the number of the treatment room selected to start the irradiation therein at that time) is inputted to theCPU101 in thecentral control unit100. For convenience of the following description, that treatment room number is assumed here to be “No. 1”. In other words, thetreatment room2A is assumed to be the selected treatment room.
• Based on both the selected treatment room number (i.e., beam course information) and the parameters (such as the irradiation energy, the irradiation dose, and the gantry angle) contained in the treatment planning data and required for specifying the beam, theCPU101 creates control command data (command value group) for supply of excitation power to the respective magnets from a power supply control table that is previously stored in the disk103 (e.g., a hard disk or a CD-ROM) disposed in thecentral control unit100. One example of the power supply control table will now be described with reference toFIG. 5. As shown inFIG. 5, corresponding to respective values (70, 80, 90, . . . [MeV] in the illustrated example) of the irradiation energy, various parameters are preset which include excitation power values (though simply denoted by “ . . . ” in the table, concrete numerical values are put in fact) or patterns of the excitation power values supplied to the quadrupole magnets9,13 and the bending magnets10,14 in the charged particle beam generator1 including the synchrotron12, the quadrupole magnets18,19 and20 and the bending magnet17 in the first beam transport system4, the quadrupole magnets22A,24A and the steering magnets7HA,7VA,8HA and8VA in the second beam transport system5A for the treatment room2A, the quadrupole magnets22B,24B and the steering magnets7HB,7VB,8HB and8VB in the second beam transport system5B for the treatment room2B, the quadrupole magnets22C,24C and the steering magnets7HC,7VC,8HC and8VC in the second beam transport system5C for the treatment room2C, and the quadrupole magnet28 in the second beam transport system5D for the treatment room3, as well as electromotive values (though simply denoted by “ . . . ” in the table, concrete numerical values are put in fact) of switching power supplies162-1,162-2,162-3 and162-4 (described later). Note that the magnets are in practice disposed in a larger number in the chargedparticle beam generator1 and the respective transport systems, but only main ones of those magnets are shown. Further, in this embodiment, the power supply control table (control command data) is stored in thedisk103 while being divided into two groups (as described later in detail).
• TheCPU101 outputs the thus-created control command data to the magnetpower supply controller130. The magnetpower supply controller130 distributes the control command data, inputted from theCPU101, to theaccelerator power supply140, the beampath power supply150, the beam switchingpower supply160, and thepath switching controller170.
• More specifically, the magnetpower supply controller130 distributes, to theaccelerator power supply140, those ones of the created control command data which are related to thequadrupole magnets9,13 and the bendingmagnets10,14 in the chargedparticle beam generator1. Theaccelerator power supply140 comprises, for each magnet, a control unit (so-called ACR, not shown) having the control function to hold a constant current of a desired value, and a power supply unit (not shown) corresponding to each ACR. Each ACR controls the corresponding power supply unit in accordance with the control command data inputted from the magnetpower supply controller130, whereby the magnitudes of respective currents supplied from the power supply units to thequadrupole magnets9,13 and the bendingmagnets10,14 are controlled.
• Also, the magnetpower supply controller130 distributes, to the beampath power supply150, those ones of the created control command data other than the data for the chargedparticle beam generator1, which are related to thequadrupole magnets18,19 and20 and the bendingmagnet17 in the first beam transport system4, thequadrupole magnets22A,24A and the steering magnets7HA,7VA,8HA and8VA in the secondbeam transport system5A for thefirst treatment room2A, thequadrupole magnets22B,24B and the steering magnets7HB,7VB,8HB and8VB in the secondbeam transport system5B for thesecond treatment room2B, thequadrupole magnets22C,24C and the steering magnets7HC,7VC,8HC and8VC in the secondbeam transport system5C for thethird treatment room2C, and thequadrupole magnet28 in the secondbeam transport system5D for thefourth treatment room3. The control command data distributed to the beampath power supply150 differs depending on the information regarding the treatment room having the top priority, which has been decided by thetreatment sequence controller120, i.e., the information indicating the treatment room number. For example, when the indicated number of the treatment room in which treatment is going to be performed is “No. 1” as mentioned above, the magnetpower supply controller130 distributes, to the beampath power supply150, the control command data for thequadrupole magnets18,22A and24A, the steering magnets7HA,7VA,8HA and8VA, and the bendingmagnet17, which are disposed in the beam path for introducing the ion beam from thesynchrotron12 to the treatment number indicated by the treatment room number. When the indicated number of the treatment room in which treatment is going to be performed is other than “No. 1”, the magnetpower supply controller130 distributes the control command data for the corresponding magnets in a similar way. Like theaccelerator power supply140, the beampath power supply150 comprises, for each magnet, a control unit (so-called ACR, not shown) having the control function to hold a constant current of a desired value, and a power supply unit (not shown) corresponding to each ACR. Each ACR controls the corresponding power supply unit in accordance with the control command data inputted from the magnetpower supply controller130, whereby the magnitudes of respective currents supplied from the power supply units to the corresponding magnets are controlled.
• Further, the magnetpower supply controller130 distributes power supply control data for the switching power supplies162-1 to162-4, which is also contained in the created control command data, to the switchingpower supply160, and at the same time it outputs treatment room number data (No. 1 inFIG. 4) to thepath switching controller170. In accordance with treatment room number data from the magnetpower supply controller130, thepath switching controller170 performs switching control of various switches (not shown) provided on theswitch panel180. Like theaccelerator power supply140, the switchingpower supply160 comprises four control units (so-called ACR, not shown) each having the control function to hold a constant current of a desired value, and four power supply units (i.e., the switching power supplies162-1 to162-4 shown inFIG. 5) corresponding to the ACR's. The power supply162-1 supplies currents to theswitching magnet6A and thebending magnet21A in thetreatment room2A. The power supply162-2 supplies a current to thebending magnet23A therein, the power supply162-3 supplies a current to thebending magnet25A therein, and the power supply162-4 supplies a current to thebending magnet26A therein. This is similarly applied to the case in which treatment is performed in each of theother treatment rooms2B,2C. In other words, each ACR controls the corresponding power supply unit in accordance with the power supply control data inputted from the magnetpower supply controller130, whereby the magnitudes of respective currents supplied from the power supply units to the corresponding magnets are controlled. Furthermore, thepath switching controller170 performs switching control of the various switches provided on theswitch panel180 in accordance with the treatment room number data, whereby the current supply destination to which the current is supplied from each power supply (i.e., the treatment room number) is controlled.
• When the settings of excitation currents for the respective magnets, which are performed by theaccelerator power supply140, the beampath power supply150, the beam switchingpower supply160, and thepath switching controller170, have completed in such a way, the magnetpower supply controller130 outputs a signal for displaying the completion of the settings to theCPU101 in thecentral control unit100. Correspondingly, theCPU101 outputs, to thedisplay39 of theoperator console37, a signal indicating that the final setup on the machine side has completed. In response to such a display signal, thedisplay39 presents display for indicating the completion of the final setup on the machine side (i.e., display for confirming the final intent to start the irradiation). Then, when the irradiation instruction switch (or button)42 is depressed by an authorized person, for example, a doctor (an operator is also allowed overseas, but in Japan the authorized person is statutorily limited to only a doctor from the viewpoints of safety and humanity), a corresponding irradiation start instruction signal is inputted to theCPU101 in thecentral control unit100.
• Then, thecentral control unit100 outputs an emission instruction signal and an acceleration instruction signal, respectively, to thelinac11 and the above-mentioned RF cavity of thesynchrotron12. Responsively, the ion beam emitted from the chargedparticle beam generator1 is accelerated in thesynchrotron12, and the ion beam extracted from thesynchrotron12 is transported to the first beam transport system4. Further, the ion beam is introduced to one of the secondbeam transport systems5A to5D corresponding to one of thetreatment rooms2A to2C and3 in which the patient as an irradiation target is present. The ion beam is then irradiated to the diseased part in the body of the patient30A in an optimum form, as per the treatment planning, through one of theirradiation apparatuses15A to15C and16 in thetreatment rooms2A to2C and3.
• In the particle therapy system having the basic construction described above, the most important feature of the present invention resides in that, in thecentral control unit100, the control command data listed in the power supply control table ofFIG. 5 is stored in thedisk103 while being divided into two groups.
• FIG. 6 is a functional block diagram showing those ones of the functions of thecentral control unit100 which are related to a process for storing the control command data. As shown inFIG. 6, thedisk103 has a group-1 data storage (first command value storing means)103A for storing control command data belonging to a group 1 (hereinafter referred to as “group-1 data”; first command value group) which is contained in the control command data shown, by way of example, inFIG. 5, a group-2 data storage (second command value storing means)103B for storing control command data belonging to a group 2 (hereinafter referred to as “group-2 data”; second command value group) which is also contained in the control command data, and an index data storage (index information storing means)103C for storing index data (index information) to make the group-1 data and the group-2 data correspondent to each other. Also, amemory102 includes amagnet information memory102A in which magnet information required for a data storage/read processing unit101C (described later) to write and read data is stored, an energycharacteristic parameter memory102B in which an energy development algorithm is stored, and a gantrystructure parameter memory102C in which a gantry angle development algorithm is stored. Further, theCPU101 includes adisplay processing unit101A for processing display information displayed on thedisplay39 of theconsole37; adata setting unit101B for setting the control command data outputted to the magnetpower supply controller130, the data storage/read processing unit (reading means)101C for executing write and read of data in and from the group-1data storage103A, the group-2data storage103B, and theindex data storage103C; an energy development processing unit (energy development computing means)101D for newly computing the group-1 data and the group-2 data depending on the beam energy by using the energy development algorithm stored in the energycharacteristic parameter memory102B; and a gantry angle development processing unit (angle development computing means)101E for newly computing the group-2 data depending on the rotation angle of the rotating gantry by using the gantry angle development algorithm stored in the gantrystructure parameter memory102C. The gantry angle development algorithm stored in the gantrystructure parameter memory102C means parameters of the type empirically determined from the structure and characteristics of the rotating gantry. Also, the energy development algorithm stored in the energycharacteristic parameter memory102B means parameters of the type empirically determined from the structures of the ion source (not shown), the pre-stage chargedparticle beam generator11 and thesynchrotron12, and from overall characteristics of the chargedparticle beam generator1.
• FIG. 5 shows classification into the group-1 data stored in the group-1data storage103A and the group-2 data stored in the group-1data storage103B. In this embodiment, as shown inFIG. 5, the control command data for the steering magnets7VA-7VC,7HA-7HC,8VA-8VC and8HA-8HC disposed in the gantry system is classified into the group-2 data, and the control command data for the other magnets is classified into the group-1 data. The control command data for the steering magnets7VA-7VC,7HA-7HC,8VA-8VC and8HA-8HC is command data depending on the rotation angle of the rotating gantry. This is because, when therotating drum50 of the rotating gantry is rotated, the beam path is distorted by the weight of therotating drum50 itself and the beam position must be finely adjusted with the steering magnets7VA-7VC,7HA-7HC,8VA-8VC and8HA-8HC. The control command data for the other magnets is command data not depending on the gantry angle.
• The index data stored in theindex data storage103C is added to one set of control command data (i.e., command data for all the magnets corresponding to each level of beam energy shown inFIG. 5) in a one-to-one relation.FIG. 7 is an illustration showing one example of the index data displayed on thedisplay39 of theconsole37. As shown inFIG. 7, the index data includes the file name of the control command data, the name of a person having prepared the data, and the name of a person having approved it. From the information displayed as the index data, the operator can easily confirm the contents of the control command data. The index data further includes the beam energy, the course (i.e., the treatment room number;courses1,2,3 and4 corresponding respectively to thetreatment rooms2A,2B,2C and3), the beam intensity (corresponding to the irradiation dose in the treatment planning data), and the gantry angle. Those items are parameters required to specify the beam. It is needles to say that the index data may include other parameters for giving the operator more comprehensive understanding.
• FIG. 8 is a flowchart showing a flow of the process for storing the control command data to prepare the power supply control table in thedisk103 disposed in thecentral control unit100.
• First, in step S10, control command data is prepared by the operator adjusting the control command data applied to the respective magnets while actually irradiating the beam. Based on the prepared control command data, the energydevelopment processing unit101D computes control command data (as described later in more detail) by using the energy development algorithm stored in the energycharacteristic parameter memory102B. Further, the gantry angledevelopment processing unit101E computes control command data (as described later in more detail) by using the gantry angle development algorithm stored in the gantrystructure parameter memory102C.
• In next step S20, the operator inputs parameters from theconsole37 while looking at an entry screen displayed on thedisplay39, by way of example, as shown inFIG. 7, thereby preparing index data regarding those items of the control command data prepared in step S10 which are to be stored. The prepared index data is stored in theindex data storage103C through the data storage/read processing unit101C.
• In next step S30, the data storage/read processing unit101C picks up and defines an index number corresponding to the index data prepared in step S20.
• In next step S40, the data storage/read processing unit101C stores the index number picked up in step S30 in each of the group-1data storage103A and the group-2data storage103B. When the group-1 data and the group-2 data are read by the data storage/read processing unit101C, the index number is used as a key for specifying the corresponding group-1 data and group-2 data. Stated another way, the index number stored in each of the group-1data storage103A and the group-2data storage103B serves to make the group-1 data and the group-2 data belonging to the same set of control command data correspondent to each other.
• In next step S50, by using the parameters stored in themagnet information memory102A, the data storage/read processing unit101C determines on the basis of one item by one item whether the prepared control command data is command data required for the relevant course. If the command data is not required for the relevant course, the determination is not satisfied and the command data is set to “0” in next step S60, followed by proceeding to step S100 described later. In practice, for example, when treatment is performed in thetreatment room2A, the command data for the magnets downstream of thequadrupole magnet19 is set to “0”. If the command data is required for the relevant course, the determination is satisfied, followed by proceeding to step S70.
• In next step S70, by using the parameters stored in themagnet information memory102A, the data storage/read processing unit101C determines whether the prepared control command data belongs to the group-1 data. In practice, it is determined whether the magnets to which the command data is to be outputted are the steering magnets7VA-7VC,7HA-7HC,8VA-8VC and8HA-8HC. If the magnets to which the command data is to be outputted are those steering magnets, the determination is not satisfied, followed by proceeding to step S80 in which the command data is classified as group-2 data and stored in the group-2data storage103B. Then, the control flow shifts to step S100 (described later). If the magnets to which the command data is to be outputted are not those steering magnets, the determination is satisfied, followed by proceeding to step S90 in which the command data is classified as group-1 data and stored in the group-1data storage103A. Then, the control flow shifts to step S100.
• In step S100, the data storage/read processing unit101C determines whether the processing of steps S50 to S90 has been completed for all items of the prepared control command data. If not yet completed, the control flow returns to step S50 to repeat the processing of steps S50 to S90. If all items of the necessary command data have been stored, the determination is satisfied and the control flow comes to an end.
• FIG. 9 is a table showing one example of the control command data newly computed in the gantry angledevelopment processing unit101E by using the gantry angle development algorithm.
• As mentioned above, the operator first prepares control command data by adjusting control command data applied to the respective magnets while actually irradiating the beam. It is here assumed that the control command data indicated by51 inFIG. 9, i.e., the control command data representing the beam energy of 50 MeV, the beam intensity of 100%, the course1 (treatment room2A), and the gantry angle of 0 degree, has been prepared by the operator. Based on thecontrol command data51 thus prepared, the gantry angledevelopment processing unit101E automatically computes the group-2 data depending on the gantry angle (e.g., the group-2 data covering the gantry angle in the range of 0.5 to 359.5 degrees in units of 0.5 degree) by using the gantry development algorithm. An area indicated by a double-headedarrow52 inFIG. 9 represents the group-2 data newly prepared at this time. The newly prepared group-2 data is sent to the data storage/read processing unit101C and is stored in the group-2data storage103B in accordance with the flowchart shown inFIG. 8. Then, the operator newly prepares index data with, e.g., entry from theconsole37, and the prepared index data is stored in theindex data storage103C through the data storage/read processing unit101C. In addition, an index number is also defined. Since the group-1 data does not depend on the gantry angle as described above, the group-1 data in thecontrol command data51 can be used in common to all of the group-2 data newly computed.
• On the other hand,FIG. 10 is a table showing one example of the control command data newly computed in the energydevelopment processing unit101D by using the energy development algorithm.
• As mentioned above, the operator first prepares control command data by adjusting the control command data applied to the respective magnets while actually irradiating the beam. It is here assumed that the control command data indicated by61,62 inFIG. 10, i.e., the control command data representing the beam energy of 50 MeV, the beam intensity of 100%, the course1 (treatment room2A) and the gantry angle of 0 degree, and the control command data representing the beam energy of 100 MeV, the beam intensity of 100%, the course1 (treatment room2A) and the gantry angle of 0 degree, have been prepared by the operator. Based on thecontrol command data61,62 thus prepared, the energydevelopment processing unit101D automatically computes the group-1 data and the group-2 data depending on the beam energy (e.g., the group-1 data and the group-2 data covering the beam energy in the range of 50.5 to 100 MeV in units of 0.5 MeV) by using the energy development algorithm. An area indicated by a double-headedarrow63 inFIG. 10 represents the group-1 data and the group-2 data both newly prepared at this time. The newly prepared group-1 data and group-2 data are sent to the data storage/read processing unit101C and are stored respectively in the group-1data storage103A and the group-2data storage103B in accordance with the flowchart shown inFIG. 8. Then, the operator newly prepares index data with, e.g., entry from theconsole37, and the prepared index data is stored in theindex data storage103C through the data storage/read processing unit101C. In addition, an index number is also defined. In this way, the power supply control table is prepared and stored in thedisk103 disposed in thecentral control unit100.
• The operation of the particle therapy system of this embodiment, having the above-described construction, will be described below with reference toFIG. 11.FIG. 11 a time chart showing a flow of the operation and control over time in the particle therapy system according to this embodiment.
• TheCPU101 in thecentral control unit100 reads, from thestorage110, the treatment planning data regarding the patient who is going to take the irradiation treatment, and outputs the necessary data to the respective controllers via theirradiation controller40. The respective controllers perform the adjustment of the gantry angle, the setting of the irradiation apparatus15, the positioning of thetreatment couch29A, etc. When those patient setups are completed, the operator depresses thesetup completion switch38 on theoperator console37, whereupon the patient ready signal is outputted to thetreatment sequence controller120. Thetreatment sequence controller120 decides the sequence of treatments to be performed in thetreatment rooms2A,2B,2C and3 in accordance with the input sequence of the patient ready signals. A treatment room signal indicating the decided treatment sequence is inputted to theCPU101 in thecentral control unit100. By using the thus-inputted treatment room signal (i.e., beam course information) and the parameters (such as the irradiation energy, the irradiation dose (beam intensity), and the gantry angle) which are contained in the treatment planning data and are required to specify the beam, theCPU101 creates control command data for supply of excitation power to the respective magnets based on the power supply control table that is stored in thedisk103 disposed in thecentral control unit100. The control command data thus prepared is outputted to the magnetpower supply controller130 and then distributed from the magnetpower supply controller130 to theaccelerator power supply140, the beampath power supply150, the beam switchingpower supply160, and thepath switching controller170. When thosepower supplies140,150 and160 and thepath switching controller170 have completed the settings of excitation currents supplied to the respective magnets, the magnetpower supply controller130 outputs a signal indicating the completion of the equipment settings to theCPU101 in thecentral control unit100, whereupon theCPU101 outputs a signal indicating the completion of the final setup on the machine side to thedisplay39 of theoperator console37. Correspondingly, thedisplay39 presents display for indicating the completion of the final setup on the machine side. Then, when theirradiation instruction switch42 is depressed by, e.g., a doctor, a corresponding irradiation start instruction signal is inputted to theCPU101 in thecentral control unit100. In response to the irradiation start instruction signal, theCPU101 outputs an emission instruction signal and an acceleration instruction signal, respectively, to thelinac11 and the above-mentioned RF cavity of thesynchrotron12. As a result, the ion beam from the chargedparticle beam generator1 is extracted and irradiated to the diseased part in the body of the patient30A through the irradiation apparatus in the relevant treatment room.
• As shown inFIG. 11, a treatment time from the patient setup in each treatment room to the end of the beam irradiation is divided primarily into a patient setup time (i.e., a time required to complete the setup for the patient) T1, a beam setup time T2, and a beam irradiation time T3. In the beam setup time T2, a time required for creating the control command data occupies a large part though it is shown short inFIG. 11 for easier understanding of a signal flow.
• The particle therapy system of this embodiment having been described above in detail operates with the following advantages.
• In this embodiment, the control command data is stored while being classified into two groups such that, of the respective magnets disposed in the chargedparticle beam generator1 and thebeam transport systems4,5A,5B,5C and5D for transporting the ion beam extracted from the chargedparticle beam generator1 to theirradiation apparatuses15A-15C and16, the control command data for the steering magnets7HA-7HC,7VA-7VC,8HA-8HC and8VA-8VC is classified into the group-2 data, and the control command data for the other magnets is classified into the group-1 data. Classifying, as another group, only the control command data depending on the gantry angle is advantageous in that, as to the control command data for the beam types differing only in the angle of the rotating gantry, it is just required to store the group-2 data alone in the group-2data storage103B, whereas the group-1 data can be used in common. The number of the steering magnets disposed in the gantry transport system, which belong to the group-2 data, is several (four in this embodiment) at maximum in each treatment room (i.e., per course). On the other hand, though depending on the number of courses, the number of the other magnets belonging to the group-1 data is usually about 30 to 150 (FIG. 5 shows only the main magnets and hence includes a relatively small number of magnets). With this embodiment, therefore, as to the control command data for the beam types differing only in the angle of the rotating gantry, the group-1 data for about 30 to 150 magnets can be used in common, whereas it is just required to store the group-2 data alone for several magnets at maximum depending on the gantry angle. Accordingly, the amount of the command data to be stored can be greatly reduced in comparison with the known system in which the control command data for the respective magnets is all simply stored as it is. As a result, it is possible to cut a search time required for specifiying, from among the stored control command data, the necessary command data corresponding to the requested beam type. In other words, the time required for creating the control command data, shown inFIG. 11, can be shortened, whereby the beam setup time T2 can be shortened. Usually, in a particle therapy system including a plurality of treatment rooms as in this embodiment, during a period in which the beam setup and the beam irradiation are performed in one treatment room, a next treatment room completes a patient setup and comes into a standby state. Therefore, as soon as the irradiation has completed in one treatment room, the beam setup for the next treatment room is performed at once. Accordingly, if the beam setup time T2 is prolonged, the standby time of the next treatment room is prolonged and treatment efficiency is reduced correspondingly. In contrast, with this embodiment, since the beam setup time T2 can be cut, the number of patients treated in one treatment room per unit time can be increased. Moreover, since the amount of the command data to be stored can be greatly reduced as described above, it is possible to reduce the resources (such as a hard disk or a CD-ROM) necessary for storing the control command data, to improve convenience in handling of data, and to cut the cost.
• Also, with this embodiment, the energydevelopment processing unit101D and the gantry angledevelopment processing unit101E automatically compute and store the control command data depending on the beam energy and the gantry angle, respectively. Therefore, whatever beam energy and whatever gantry angle are requested from any of the treatment rooms, the beam setting can be automatically performed in response to the request, and the range within which thecentral control unit100 is able to automatically perform the beam setting can be drastically enlarged.
• Further, with this embodiment, the index data is added to one set of control command data in a one-to-one relation, and the index number corresponding to the index data is defined and stored when the control command data is classified into the group-1 data and the group-2 data. Based on the index data, the operator can easily confirm the contents of the control command data, and can write and read the control command data as one set without being aware of the fact that the control command data is stored in two classified groups. In other words, lowering of convenience in handling of data can be avoided which is otherwise caused with classification of the control command data into two groups. Further, when reading the command data from the two groups, the defined index number is used as a key for specifying both the group-1 data and the group-2 data corresponding to it. Therefore, the group-1 data and the group-2 data can be avoided from being read in a false combination.
• While the beam irradiation method in the irradiation apparatus is not limited to a particular one in the above-described one embodiment of the present invention, the present invention is likewise applicable to, e.g., a particle therapy system including an irradiation apparatus of the type irradiating an ion beam while automatically changing beam energy to plural levels (i.e., the energy scanning type). In such a case, plural sets of the control command data corresponding to the plural energy levels must be selected from the power supply control table stored in thedisk103 in response to the beam request from each treatment room. Stated another way, in that case, the search for the control command data executed in the above-described one embodiment requires to be made plural times corresponding to the plural energy levels. It is hence possible to more effectively utilize the advantage of the present invention that the number of patients treated in one treatment room per unit time by cutting the search time.
• While the above-described one embodiment of the present invention is applied to the particle therapy system including the synchrotron, the present invention can also be applied to a particle therapy system including a cyclotron.

Claims (19)

1. A particle therapy system comprising:

a charged particle beam generator for generating a charged particle beam;

an irradiation apparatus for irradiating the charged particle beam extracted from said charged particle beam generator to an irradiation target;

a beam transport system for transporting the charged particle beam extracted from said charged particle beam generator to said irradiation apparatus; and

a control unit for producing a group of command values to command excitation currents for magnets disposed in said charged particle beam generator and said beam transport system, said group of command values being classified into a first command value group and a second command value group.

2. A particle therapy system according toclaim 1, further comprising a rotating gantry including said irradiation apparatus and installed rotatably,

wherein said control unit produces the group of command values as a command value group depending on a rotation angle of said rotating gantry and a command value group not depending on a rotation angle of said rotating gantry.

3. A particle therapy system according toclaim 1, wherein said control unit employs the first command value group to command the excitation currents for magnets belonging to a first group of said magnets disposed in said beam transport system, and employs the second command value group to command the excitation currents for magnets belonging to a second group of said magnets disposed in said beam transport system.

4. A particle therapy system according toclaim 3, wherein said control unit employs the first or second command value group to command the excitation currents for steering magnets disposed in a gantry transport system as a part of said beam transport system which is located near said rotating gantry.

5. A particle therapy system according toclaim 1, further comprising angle development computing means for computing the first or second command value group depending on the rotation angle of said rotating gantry.

6. A particle therapy system according toclaim 2, further comprising angle development computing means for computing the first or second command value group depending on the rotation angle of said rotating gantry.

7. A particle therapy system according toclaim 3, further comprising angle development computing means for computing the first or second command value group depending on the rotation angle of said rotating gantry.

8. A particle therapy system according toclaim 4, further comprising angle development computing means for computing the first or second command value group depending on the rotation angle of said rotating gantry.

9. A particle therapy system according toclaim 1, further comprising energy development computing means for computing the first and second command value groups depending on energy of the charged particle beam extracted from said charged particle beam generator.

10. A particle therapy system according toclaim 2, further comprising energy development computing means for computing the first and second command value groups depending on energy of the charged particle beam extracted from said charged particle beam generator.

11. A particle therapy system according toclaim 3, further comprising energy development computing means for computing the first and second command value groups depending on energy of the charged particle beam extracted from said charged particle beam generator.

12. A particle therapy system according toclaim 4, further comprising energy development computing means for computing the first and second command value groups depending on energy of the charged particle beam extracted from said charged particle beam generator.

13. A particle therapy system according toclaim 1, further comprising first command value storing means for storing the first command value group, second command value storing means for storing the second command value group, and index information storing means for storing index information to make the first command value group and the second command value group correspondent to each other.

14. A particle therapy system according toclaim 2, further comprising first command value storing means for storing the first command value group, second command value storing means for storing the second command value group, and index information storing means for storing index information to make the first command value group and the second command value group correspondent to each other.

15. A particle therapy system according toclaim 3, further comprising first command value storing means for storing the first command value group, second command value storing means for storing the second command value group, and index information storing means for storing index information to make the first command value group and the second command value group correspondent to each other.

16. A particle therapy system according toclaim 4, further comprising first command value storing means for storing the first command value group, second command value storing means for storing the second command value group, and index information storing means for storing index information to make the first command value group and the second command value group correspondent to each other.

17. A particle therapy system according toclaim 5, further comprising first command value storing means for storing the first command value group, second command value storing means for storing the second command value group, and index information storing means for storing index information to make the first command value group and the second command value group correspondent to each other.

18. A particle therapy system according toclaim 6, further comprising first command value storing means for storing the first command value group, second command value storing means for storing the second command value group, and index information storing means for storing index information to make the first command value group and the second command value group correspondent to each other.

19. A particle therapy system according toclaim 13, further comprising reading means for reading the first command value group and the second command value group, which are made correspondent to each other, out of said first command value storing means and said second command value storing means by using the index information read out of said index information storing means.

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