CN105031833B

CN105031833B - The dosage verifying system of radiotherapy unit

Info

Publication number: CN105031833B
Application number: CN201510537536.1A
Authority: CN
Inventors: 周付根; 吴大可; 姚进; 刘博�; 李超; 许轩昂; 郭斌; 梁斌; 廖华宣; 韦崇高
Original assignee: Rui Dima Medical Science And Technology Co Ltd
Current assignee: Rui Dima Medical Science And Technology Co Ltd
Priority date: 2015-08-28
Filing date: 2015-08-28
Publication date: 2018-02-06
Anticipated expiration: 2035-08-28
Also published as: CN105031833A

Abstract

The invention belongs to a kind of dosage verifying system of radiotherapy unit in field of medical device, is made up of data transmission module, image registration module, profile mapping block, tissue change analysis module, four-dimensional image modeling module, dose reconstruction module and dose assessment module.The present invention can be according to the relevant image information gathered in therapeutic process, analyze target area and the actual exposure dose born of normal organ, patient tissue organ mutation analysis function and exposure dose Reconstruction of The Function are provided, realize that the online and offline adaptive adjustment for the treatment of plan provides foundation for radiotherapy unit.

Description

The dosage verifying system of radiotherapy unit

Technical field

The invention belongs to field of medical device, and in particular to a kind of dosage verifying system of radiotherapy unit.

Background technology

With the development of radiotherapy technology and equipment, the target of radiotherapy towards " accurate radiotherapy " is advanced, that is, requires radiation Precise Diagnosis is carried out in therapeutic process, is accurately positioned, accurately plan and accurate treatment.Therefore, the quality for radiotherapy is strengthened Control and quality assurance are most important, and wherein dosage verifying technology is one of means.Used in conventional radiotheraphy Film making checking means, but the film making dosage verifying of two dimension can only be carried out, it can't realize that 3-dimensional dose is distributed real-time verification.One A little image guided radiation therapy (Image-guided Radiotherapy, IGRT) equipment, are scanned using pencil-beam x-ray tomography （CBCT）As image documentation equipment, the guiding in real time tracking treatment of tumor target is realized, but in successive treatment, the form meeting of tumour Change, such as Tumor shrank, tissue morphology regression etc., if continuing the treatment plan started, exposure dose can be caused not Uniformly, and if the plan of reformulating, need to re-start CT scan, extend the time, increase cost.

Therefore, the accurate conformal radiation therapy for moving tumour be the subject matter that faces of current cancer field of radiation therapy it One.In recent years, kinds of tumors tracking treatment technology is proposed to solve the problem and achieves relatively good effect.Tumour chases after Track treatment technology the position of real-time estimate tumour and is moved according to this over the course for the treatment of by being modeled to the characteristics of motion of tumour State adjusts colimated light system（Such as position of MLC leaf positions, robot collimater etc.）It is tracked treatment.In addition, tumour chases after Track therapeutic equipment can also be used over the course for the treatment of by treatment-related information according in certain frequency write-in treatment journal file In the checking of successive treatment quality.The treatment relevant information of record includes but is not limited to the tumour position that ray goes out number, tracked Put, the position of colimated light system etc..But the conventional dosage verifying method based on CBCT images does not account for tumour in therapeutic process Motion and therapeutic process in colimated light system position change, therefore be not applied for tumour tracking treatment technology dosage test Card.

It is a kind of new radiation therapy technology based on image-guided stereotactic surgery/radiotherapy.Compared to routine Stereotactic surgery/radiotherapy technology, determined over the course for the treatment of without using bone based on image-guided stereotactic surgery/radiotherapy Position（skeletal fixation）Device limits the motion of patient, but periodically detects patient body position using imaging methods Change.If monitoring the position chanP of patient and change being within the scope of it can compensate, dynamic adjusts colimated light system Position realize the accurate irradiation of tumour.If patient body position's change is beyond the scope that can be compensated, pause treatment is simultaneously To continual cure after patient's progress again pendulum position.Over the course for the treatment of, image-guided stereotactic surgery/radiotherapy apparatus can incite somebody to action Treatment-related information is treated in journal file according to certain frequency write-in, the checking for successive treatment quality.Record Treatment relevant information includes but is not limited to ray and goes out position of knub position that is several, tracking, colimated light system etc..It is but conventional Dosage verifying method based on CBCT images does not account for the change of patient body position in therapeutic process and colimated light system position Adjustment, therefore it is not applied for the dosage verifying based on image-guided stereotactic surgery/radiotherapy technology.

The content of the invention

The invention aims to overcome existing radiotherapy unit to cause prescribed dose because patient target area changes Misalignment, the extended treatment time, the defects of increasing treatment cost, the dosage verifying system of radiotherapy unit a kind of is provided for people System, it can analyze target area and the actual exposure dose born of normal organ according to the relevant image information gathered in therapeutic process, carry For patient tissue organ mutation analysis function and exposure dose Reconstruction of The Function, realize that treatment plan is online for radiotherapy unit Foundation is provided with offline adaptive adjustment.

The purpose of the present invention is realized by following technical proposals：

The dosage verifying system of the radiotherapy unit of the present invention, it is characterised in that dosage verifying system is mainly passed by data Defeated module, image registration module, profile mapping block, tissue change analysis module, four-dimensional image modeling module, dose reconstruction mould Block and dose assessment module composition, wherein, data transmission module is connected with data server, data transmission module also respectively with figure As registration module, profile mapping block, four-dimensional image modeling module are connected with dose reconstruction module；Image registration module respectively with Profile mapping block, four-dimensional image modeling module are connected with dose assessment module；Profile mapping block is organized to take turns online through patient Exterior feature is connected with tissue change analysis module and dose assessment module respectively；Tissue change analysis module and data transmission module and four Dimension（4D）Radiotherapy treatment planning system is connected；Four-dimensional image modeling module is connected with dose reconstruction module；Dose reconstruction module with Dose assessment module is connected；Dose assessment module is connected with data transmission module and 4D radiotherapy treatment planning systems.

In such scheme, the data transmission module is communicated by network connection with data server, obtains dosage verifying Required related data, data server is arrived into the result storage.

In such scheme, described image registration module provides rigid body and deformable registration method, and mould is modeled for four-dimensional image The registration of four-dimensional CT/CBCT differences respiratory phase 3-D view in block；For planning CT images and CBCT in profile mapping block The deformable registration of image.

In such scheme, the profile mapping block is provided using planning contours information, the Registration of Measuring Data module of patient Plan the deformation vectors field between CT and online CBCT images, calculate mapping of the planning contours to CBCT images；Profile is mapped As a result after modifying, the online tissue contours of patient are obtained；Profile mapping block includes following submodule：a）Three-dimensional grid is built Submodule：According to tissue three-dimensional contour line, the three-dimensional grid surface model of tissue is built；Specially：First with the original of tissue Beginning three-dimensional contour line reconstructs the three-dimensional grid surface of tissue, then using Deformation Field interpolation technique, the deformation obtained from registration The deformation vectors of each three-dimensional grid apex are obtained in vector field, and coordinate transform is carried out to grid vertex, profile is obtained and reflects The three-dimensional grid surface model penetrated under target image coordinate system；b）Three-dimensional module cutting submodule：Utilize the three dimensional network after deformation The three-dimensional contour line that lattice surface model cutting goes out on arbitrary plane；Specially：The plane according to where cutting into slices target image, to three-dimensional Surface mesh model carries out cutting, calculates cutting and the slice location of each three-dimensional grid, and by connecting grid cutting in order Point, obtain corresponding contour line；c）Profile range conversion submodule：Using tissue three-dimensional contour line obtain corresponding to it is three-dimensional away from From figure；Specially：Sat first according to original contour line computation profile binary map and profile distance map, the image of profile distance map Mark system with for sketch outline line image it is consistent, in range image positioned at contoured interior voxel value be just, profile exterior Voxel value is negative, and its absolute value is minimum distance of the voxel to three-D profile surface；Then using deformation vectors field to three-dimensional Distance map carries out deformation conversion, obtains the profile distance map under profile mapping objects image space coordinate；Finally extract distance map In pixel value is 0 on each faultage image isopleth, the isopleth is the mapping result of three-dimensional contour line.

In such scheme, the tissue change analysis module passes through online group of quantitative comparison patient care plan profile and patient Driving wheel exterior feature analyzes change of the histoorgan in position, volume and vpg connection, and by data transmission module that patient is online Tissue contours are saved in data server；The form in multiple gradation undertissues can be also checked and analyzed simultaneously, intuitively shows group Knit the situation of change with therapeutic process.

In such scheme, when the four-dimensional image modeling module utilizes the four-dimensional CT images difference that image registration module provides Deformation vectors field between phase, establish the four-dimensional image model of patient；Mainly include image registration and four-dimensional movement models two Submodule：a）Image registration submodule is carried out two-by-two to each group 3-D view in 4DCT/4DCBCT according to the order of respiratory phase Registration, obtain the deformation vectors field between two adjacent groups 3-D view；b）Four-dimensional movement modeling submodule comprehensive utilization image is matched somebody with somebody The each group deformation vectors field that quasi- submodule obtains, according to respirometric continuity, periodic characteristics, structure B-spline motion mould Type or based on PCA（Principal component analysis）Motion model, so as to improve the degree of accuracy of movable information.

In such scheme, the dose reconstruction module is gone out currently using four-dimensional image model or three-dimensional CBCT image reconstructions The dosage that gradation patient bears, mainly include electron density demarcation submodule and Rapid Dose Calculation submodule：

a）Electron density demarcates submodule by being intended to CT image registrations to CBCT images, obtains body in CBCT images ElementCorrespondence position on plan CT images, then utilizeThe HU values at place replace voxel in CBCT imagesThe HU values at place, The HU images for ultimately generating one group of simulation are used for determination and the Rapid Dose Calculation of organizing electronic density；

b）Rapid Dose Calculation submodule carries out Rapid Dose Calculation based on the CBCT for having demarcated electron density, and estimation patient is controlling by several times The dosage actually received in treatment；

Rebuild for the fractionated dose of static target area, Rapid Dose Calculation submodule, which considers patient body position in therapeutic process, to be changed Influence to acceptable dose；

Rebuild for the fractionated dose for moving target area, Rapid Dose Calculation submodule considers target area and other related organizations are controlling Actual motion situation, the situation of target area tracking treatment during treatment, so as to estimate more accurately patient's acceptable dose, specifically For：For each launched field, the movement locus of collimater when analysis is directed to each launched field motion compensation from therapeutic process file And range of movement, and movement locus is divided into N number of subarc of equidistant intervals；Obtain target area center at each subarc mean place Position, and according to target area center from four-dimensional image model interpolation obtain corresponding to 3 d image data, last basis The data carry out Rapid Dose Calculation；The radiation exposure machine hop count of each subarc（MU）, multiple periodic motions are come and gone for treatment head Cheng Zhong, the MU numbers sum between the subarc；By carrying out above-mentioned Rapid Dose Calculation flow to each subarc respectively, N groups three-dimensional is obtained Dosage field, it is rightIt is weighted summation and obtains the 3-dimensional dose field for each launched field；Then carried out for all launched fields Above-mentioned Rapid Dose Calculation, add up, finally give the dosage field of whole treatment plan；Wherein, interpolation obtains from four-dimensional image model The operating process of corresponding 3 d image data is：Target area four-dimensional movement model is inserted according to target area center first Value, obtains the corresponding respiratory phase in four-dimensional image model；Then basisPhase corresponding with two neighboring 3-D view Distance determine interpolation weights；Finally using motion vector field between this two groups of 3-D views to carrying out deformation change with reference to phase Change, finally give for 3-D view corresponding to the treatment subarc.

In such scheme, the dose assessment module utilizes dose reconstruction interpretation of result patient care plan dosage and interval procedure Difference between dosage, multiple gradation cumulative doses；Including dosage map submodule and dosage analysis submodule：a）Dosage map Submodule is using the deformation vectors field between plan CT images and the CBCT images of the acquisition of image registration module, by dose reconstruction mould The fractionated dose field that block calculates is mapped under plan CT image coordinate systems, obtains mapping dosage field by several times；Utilize multiple gradation Mapping dosage field bears dosage to calculate the accumulation of patient, for compared with intended dose；b）Dosage analysis submodule pair The irradiation of related organization is analyzed and compared by amount under intended dose field and reconstruction dosage field, and treatment plan is adjusted, The actual deviation measured by amount and plan of amendment patient；By comparing the intended dose of die body plan and rebuilding dosage come to system Carry out QA（Quality assurance）；The function of offer includes：The contrast of isodose, isodose surface shows, DVH（Dose volume histogram Figure）Contrast show that the contrast of section dosage is shown and difference is shown, dosage field 3D Gamma（Gamma）Analysis.

In such scheme, the step of dosage verifying system of the radiotherapy unit is used for online dosage verifying, is as follows：

A. non-rigid body model method is utilized to plan CT, to be planned the 3D CBCT image registrations for putting position for patient CT to 3D CBCT deformation vectors field, wherein deformation vectors field have recorded every bit in plan CTP _iThe corresponding points into 3D CBCT Deformation vectors；

B. the related organization's profile being intended to using above-mentioned deformation vectors field on CT is mapped on 3D CBCT, obtains patient Online tissue contours information：

a）For each related organization, structure includes the three-dimensional masking-out image of the tissue in space；Masking-out image In the value of each voxel represent profile containment relationship, when the voxel be located inside occluding contour, value is 1；When the voxel Value is 0 when outside occluding contour；

b）The three-dimensional equivalent surface model for being 1 using Marching Cube isosurface extractions method extraction voxel value；

c）The deformation vectors field obtained using step A, line translation is entered to each summit of three-dimensional equivalent surface model, obtained Three-D profile surface model after to deformation；

d）For target 3D CBCT each layer of two-dimentional axle position image, the plane being coincide with the two-dimensional image position is utilized Cutting is carried out to the three-dimensional equivalent surface model after deformation, obtains point that 3 d surface model intersects with the plane or coincidence Straight line；These points and straight line are attached in sequence, obtain the wheel organized after the deformation corresponding to the two-dimentional axle position image Profile；

e）Contour line on all two-dimentional axle position images of integration objective 3D CBCT, as maps obtained trouble by profile The online tissue contours information of person；

C. 3D CBCT images are calculated and have recorded every in 3D CBCT to the deformation vectors field of plan CT images, deformation vectors field A bitP _iThe deformation vectors of corresponding points into plan CT；Utilize HU (Hounsfield Unit) values and electron density for planning CT Transformational relation, according to the HU values of each voxels of 3D CBCT corresponding position in CT is planned calculate the voxel electron density, So as to obtain organizing electronic density map corresponding to 3D CBCT images；When calculating deformation vectors field, the meter that is obtained first to step A CT images are drawn to the deformation vectors field of the 3D CBCT imagesDFCarry out inversion calculation；Then asked using method for registering images with this Inverse transformation is intended to CT and is registrated to 3D CBCT, obtain 3D CBCT images to the plan accurate deformation vectors of CT as initial value ；

D. the exposure dose currently born by several times using organizing electronic density map calculating patient corresponding to 3D CBCT images；

E. the multiple fractionation of radiations of patient are carried out using the 3D CBCT images of different gradation collection and the exposure dose of calculating The deformation of dosage adds up；The deformation of exposure dose is cumulative to need to choose a certain group of image as reference picture, wherein reference picture For the plan CT or 3D CBCT of any collection by several times；When deformation adds up, first with deformation vectors field computation reference picture Correspondence position of each voxel in other gradation 3D CBCT images, and obtain the opening position using cubic interpolation method Dosage, finally the dosage that interpolation obtains is added up, obtain the deformation cumulative dose at some voxel location；

F. the Geometrical change situation of quantitative analysis related organization and the exposure dose change being induced by it；Geometrical change bag Include change, the coincidence factor in change front and rear profile region of tissue volume and position of centre of gravity；, can for the analysis of exposure dose change To analyze the situation of change of single fractionation of radiation dosage and multiple gradation cumulative doses；The change of dosage is born most including tissue Greatly, the change of minimum, average, median dose and dose-volume relation；Consider the tissue change situation of multiple gradation, Indices are calculated with the change curve and rate of change of interval procedure.

In such scheme, the dosage verifying system of the radiotherapy unit is to contain the dose reconstruction of movable information Step is as follows：

A. the four-dimensional image model for including histokinesis's information is established using 4D CBCT data；Four-dimensional image model includes Multigroup three-dimensional CBCT under different respiratory phases and it is different when alternate histoorgan movable information；

a）Registration two-by-two is carried out according to the order of respiratory phase to each group 3-D view in 4D CBCT, obtains two adjacent groups Deformation vectors field between 3-D view；

b）Each group deformation vectors fields is comprehensively utilized, the features such as according to respirometric continuity, periodicity, builds B-spline Motion model or the motion model based on PCA, improve the degree of accuracy of movable information；

B. the automatic of related organization's contour line is delineated on the 4D CBCT based on contour line Means of Deformation Mapping Approach：

a）Each group of 3D CBCT image registrations in 4D CBCT are counted to plan CT using non-rigid body model method CT to 3D CBCT deformation vectors field is drawn, wherein deformation vectors field have recorded every bit in plan CTP _iTo each group of 3D CBCT The deformation vectors of middle corresponding points；

b）The related organization's profile being intended to using above-mentioned deformation vectors field on CT is mapped on each group of 3D CBCT, is obtained To the online tissue contours information of patient；

C. each group of 3D CBCT image is calculated in 4D CBCT to the deformation vectors field for planning CT, wherein deformation vectors script holder Every bit in 3D CBCT is recordedP _iThe deformation vectors of corresponding points into plan CT；Turned using the HU values for planning CT with electron density Relation is changed, the electron density of the voxel is calculated according to the HU values of each voxels of 3D CBCT corresponding position in CT is planned, so as to Finally give organizing electronic density map corresponding to each group of 3D CBCT image in 4D CBCT；Calculate each group of 3D CBCT image To plan CT deformation vectors field when, the plan CT images that are obtained first to step B to the deformation vectors field of the 3D CBCT images Inversion calculation is carried out, then CT is intended to using the conversion of inverting as initial value by the use of method for registering images and is registrated to 3D CBCT, 3D CBCT images are obtained to plan CT accurate deformation vectors field；

D. according to the treatment journal file recorded in therapeutic process, the proving agent for including motion tumour tracked information is calculated Amount：

a）For each launched field B_i, from treatment journal file in analysis obtain dynamic tracing motion target area treated When collimater movement locus and range of movement, and movement locus is divided into N number of subsegment of equidistant intervals, wherein N can be by curing Life is selected as needed；

b）The position at target area center at each subsegment mean place is obtained according to treatment journal file, and according to target area center Position three-dimensional CT images data I corresponding to interpolation acquisition from 4D iconic models_iWith organizing electronic density map；

I. the target area contour line on each group of 3D CBCT obtained according to step B, is calculated with patient respiratory phase target area The curve movement of center；

ii.Correspondence position of the target area center on the central motion curve of target area at each subsegment mean place is calculated, It is determined that patient respiratory phase corresponding to current subsegmentt；

Iii. found out from 4D CBCT and patient respiratory phasetTwo groups of adjacent 3D CBCT, it is respectivelyt _iWitht _j, whereint _i≤ t _≤ t _j；It is close from organizing electronic corresponding to two groups of 3D CBCT using linear interpolation method according to the position relationship of respiratory phase Figure interpolation is spent, obtains three-dimensional CT images data I corresponding to the treatment subsegment_iWith organizing electronic density map；

c）Utilize image I_iCalculate the collimater dosage that patient bears when the subsegment is moved, wherein Rapid Dose Calculation MU numbers For dosage goes out beam MU sums in the subsegment during collimater back and forth movement tracking target area；

d）Using the above method, respectively to projection B_iEach subsegment carry out above-mentioned Rapid Dose Calculation, obtain the three-dimensional agent of N groups Measure field D_i, a certain group of image is then selected as reference picture, to N group 3-dimensional doses field D_iDeformation is carried out to add up；Reference picture can To be that plan CT either a certain group of 3D CBCT or carries out deformation on multigroup reference picture and added up in 4D CBCT；

e）Then carry out above-mentioned Rapid Dose Calculation for all launched fields, add up, finally give the dosage of whole treatment plan ；

E. using gamma analysis and dose-volume histogram method, that compares related organization under different situations bears agent Amount, and a variety of quantitative analytical datas are provided, to determine the need for carrying out Plan rescheduling；The intended dose of more single gradation and Deformation cumulative dose；Or the cumulative dose of more multiple gradation intended doses, and the deformation cumulative dose of multiple gradation Cumulative dose.

The present invention is matched by CBCT images with planning CT in planning system or planning the deformation of 4D CT images, is utilized The change of CBCT images on-line analysis patient target area and other histoorgans, the actual acceptable dose of patient is calculated, with treatment plan The dosage field of design is compared online, while different fractionated doses are added up, so as to reach dose reconstruction and checking Purpose, the dose difference as caused by organ deformation, interval procedure Set-up errors and patient and target area motion is analyzed, is drawn for dosage The adaptive radiation therapy led provides dosimeter foundation.

Scheme of the present invention has the beneficial effect that：

The invention provides patient tissue organ mutation analysis function and exposure dose Reconstruction of The Function, is controlled with reference to 4D radiation Treat planning system to use, the online and offline adaptive adjustment for the treatment of plan can be realized.Before the treatment, treatment planning systems are utilized Design the treatment plan of patient and carry out interval procedure.After each interval procedure completes patient's pendulum position, doctor can be by dosage Profile mapping function and tissue change analytic function that checking system provides carry out the profile of tissue of interest on pendulum position CBCT Delineate and mutation analysis, and the adaptive planning module provided when necessary using 4D radiotherapy treatment planning systems is to treatment plan On-line tuning is carried out, and implements the treatment plan after adjustment.After interval procedure completion, doctor can be by dosage verifying system Carry out reconstruction and assessment that patient bears dosage；And Patient treatment plan is adjusted offline when necessary, after then implementing Continuous treatment, until treatment end.

The present invention utilizes the treatment journal file recorded in therapeutic process and patient to put the 3D CBCT gathered during position, energy It is enough to adjust the dynamic position of the motion of tumour and colimated light system in the change in location of therapy area, therapeutic process in therapeutic process It is whole to take into account, obtain more accurately patient's exposure dose and implement radiotherapy checking.Suitable for image-guided stereotaxis hand The dose reconstruction of art/radiotherapy and the dose reconstruction comprising movable information, improve the accuracy of radiotherapy unit, expand and put Penetrate the scope of application of therapeutic system.

In summary, instant invention overcomes existing radiotherapy unit to cause prescribed dose to lose because patient target area changes Standard, extended treatment time, the defects of increasing treatment cost, there is provided the dosage verifying system of radiotherapy unit can be according to treatment During the relevant image information that gathers, analyze target area and the actual exposure dose born of normal organ, there is provided patient tissue device Official's mutation analysis function and exposure dose Reconstruction of The Function, realize that treatment plan is online and offline adaptive for radiotherapy unit Adjustment provides foundation.

Brief description of the drawings：

Fig. 1 is the composition schematic diagram of the present invention.

Fig. 2 is the three-dimensional grid structure submodule schematic diagram of the present invention.

Fig. 3 is the profile range conversion submodule schematic diagram of the present invention.

Fig. 4 is the radiotherapy unit schematic diagram that the embodiment of the present invention one uses.

In accompanying drawing, 1：Electron linear accelerator；2：Secondary collimator；3：Slur machine people's C arm systems；3-1：C arm supports Pedestal；3-2：C arm supports；3-3：X-ray source；3-4：X-ray detector；3-5：Positioning runner；4：Robot therapeutic bed；4-1：Treatment Bed；4-2：Robot；5：Breathe tracker；6：Therapy robot.

Embodiment：

Below in conjunction with the accompanying drawings and the present invention is described in further detail in embodiment, but the present invention is not limited only to the embodiment.

Embodiment one

The dosage verifying system of the radiotherapy unit of this example, applicable radiotherapy unit is as shown in figure 4, be a kind of point Quadrant radiotherapy unit, including compact electronic linear accelerator 1, secondary collimator 2, slur machine people C arm systems 3, Robot therapeutic bed 4, breathing tracker 5, Therapy robot 6 and 4D treatment planning systems, the Therapy robot 6 are arranged at machine At the opposite position of device people therapeutic bed 4, compact electronic linear accelerator 1 is installed on the movable end of Therapy robot 6, and described two Level collimater 2 is installed on the end of compact electronic linear accelerator 1, and the robot therapeutic bed 4 is arranged at slur machine At the opposite position of people C arm systems 3, the slur machine people C arm systems 3 include C arm support pedestals 3-1, C arm support 3-2 and two Photoimaging systems are covered, the C arm supports 3-2 is in " C " glyph shape, has positioning runner 3-5, C arm support 3-2 on C arm support pedestals 3-1 It is slidably mounted in C arm support pedestals 3-1 positioning runner 3-5；Two sets of photoimaging systems are respectively on the inside of the C arm supports 3-2 Both ends, two sets of photoimaging systems are correspondingly arranged；The Therapy robot 6, robot therapeutic bed 4, slur machine people's C arm systems 3 and breathing tracker 5 be connected by bus with integrated control subsystem, integrate control subsystem in be provided with data server.

Slur machine people C arm systems 3 described in this example can around C arm supports axis rotate+- 110 °, realize 3DCBCT into Picture, breathing tracker 5 can also be combined and realize that 4DCBCT is imaged, CBCT images are used for patient pendulum position and checking, target area dynamic chase after Track and real-time dosage verifying.

Dosage verifying system described in this example, as shown in figure 1, mainly being reflected by data transmission module, image registration module, profile Module, tissue change analysis module, four-dimensional image modeling module, dose reconstruction module and dose assessment module composition are penetrated, wherein, Data transmission module is connected with data server, data transmission module also respectively with image registration module, profile mapping block, four Dimension image modeling module is connected with dose reconstruction module；Image registration module models with profile mapping block, four-dimensional image respectively Module is connected with dose assessment module；Profile mapping block through the online tissue contours of patient respectively with tissue change analysis module and Dose assessment module is connected；Tissue change analysis module is connected with data transmission module and 4D radiotherapy treatment planning systems；It is four-dimensional Image modeling module is connected with dose reconstruction module；Dose reconstruction module is connected with dose assessment module；Dose assessment module with Data transmission module is connected with 4D radiotherapy treatment planning systems.

Data transmission module is communicated by network connection with data server, obtains the related data needed for dosage verifying, Data server is arrived into the result storage；

Wherein, the related data of acquisition includes：a）Planning data：Plan CT/4D CT images, profile information, treatment meter Draw, dosage field；b）Interval procedure information：Treatment daily record data, the CBCT/4D CBCT images recorded during interval procedure；c） Rebuild dosage field：Have been carried out treating the reconstruction dosage field of gradation；d）Have been carried out the tissue contours that treatment is delineated by several times；

The content of storage includes：a）Rebuild dosage field：The reconstruction dosage field of current gradation；b）Patient tissue profile： The tissue contours delineated on CBCT images.

Image registration module map provides rigid body and deformable registration method as registration module, in four-dimensional image modeling module The registration of four-dimensional CT/CBCT differences respiratory phase 3-D view；For planning CT images and CBCT images in profile mapping block Deformable registration.

The plan CT and online CBCT that profile mapping block is provided using planning contours information, the Registration of Measuring Data module of patient Deformation vectors field between image, calculate mapping of the planning contours to CBCT images；After being modified to profile mapping result To the online tissue contours of patient；Profile mapping block includes following submodule：a）Three-dimensional grid builds submodule（Such as Fig. 2 institutes Show）：The three-dimensional grid surface model of tissue is built according to tissue three-dimensional contour line；Specially：First with original the three of tissue Dimension profile reconstruction goes out the three-dimensional grid surface of tissue, then using Deformation Field interpolation technique, the deformation vectors obtained from registration The deformation vectors of each three-dimensional grid apex are obtained in, and coordinate transform is carried out to grid vertex, obtain profile mapping mesh Three-dimensional grid surface model under logo image coordinate system；b）Three-dimensional module cutting submodule：Utilize the three-dimensional grid table after deformation The three-dimensional contour line that surface model cutting goes out on arbitrary plane；Specially：The plane according to where cutting into slices target image, to three-dimensional grid Surface model carries out cutting, calculates cutting and the slice location of each three-dimensional grid, and by connecting grid cutting point in order, obtain To corresponding contour line；c）Profile range conversion submodule（As shown in Figure 3）：Obtained using tissue three-dimensional contour line corresponding to it Three-dimensional distance figure；Specially：First according to original contour line computation profile binary map and profile distance map, profile distance map Image coordinate system is consistent with the image for sketching outline line, and the voxel value in range image positioned at contoured interior is just profile Outside voxel value is negative, and its absolute value is minimum distance of the voxel to three-D profile surface；Then deformation vectors field is utilized Deformation conversion is carried out to three-dimensional distance figure, obtains the profile distance map under profile mapping objects image space coordinate；Finally extract Pixel value is 0 isopleth on each faultage image in distance map, and the isopleth is the mapping result of three-dimensional contour line.

Tissue change analysis module is by quantitative comparison patient care plan profile and the online tissue contours of patient come analysis group Change of the organ in position, volume and vpg connection is knitted, and is saved in the online tissue contours of patient by data transmission module Data server；The form in multiple gradation undertissues can be also checked and analyze simultaneously, it is directly perceived to show tissue with therapeutic process Situation of change.

Four-dimensional image modeling module using image registration module provide four-dimensional CT images difference phase between deformation to The four-dimensional image model of patient is established in amount field；Mainly include image registration and four-dimensional movement models two submodules：a）Image is matched somebody with somebody Quasi- submodule carries out registration two-by-two to each group 3-D view in 4DCT/4DCBCT according to the order of respiratory phase, obtains adjacent two Deformation vectors field between group 3-D view；b）Four-dimensional movement modeling submodule comprehensive utilization image registration submodule obtains each Group deformation vectors field, according to respirometric continuity, periodic characteristics, build B-spline motion model or the fortune based on PCA Movable model, so as to improve the degree of accuracy of movable information.

Dose reconstruction module goes out what current gradation patient bore using four-dimensional image model or three-dimensional CBCT image reconstructions Dosage, mainly include electron density demarcation submodule and Rapid Dose Calculation submodule：

Rebuild for the fractionated dose for moving target area, Rapid Dose Calculation submodule considers target area and other related organizations are controlling Actual motion situation, the situation of target area tracking treatment during treatment, so as to estimate more accurately patient's acceptable dose, specifically For：For each launched field, the movement locus of collimater when analysis is directed to each launched field motion compensation from therapeutic process file And range of movement, and movement locus is divided into N number of subarc of equidistant intervals；Obtain target area center at each subarc mean place Position, and according to target area center from four-dimensional image model interpolation obtain corresponding to 3 d image data, last basis The data carry out Rapid Dose Calculation；Each subarc radiation exposure machine hop count（MU）, multiple periodic motion processes are come and gone for treatment head In, the MU numbers sum between the subarc；By carrying out above-mentioned Rapid Dose Calculation flow to each subarc respectively, the three-dimensional agent of N groups is obtained Measure field, it is rightIt is weighted summation and obtains the 3-dimensional dose field for each launched field；Then carried out for all launched fields State Rapid Dose Calculation, add up, finally give the dosage field of whole treatment plan；Wherein, the interpolation acquisition pair from four-dimensional image model The operating process for the 3 d image data answered is：Row interpolation is entered to target area four-dimensional movement model according to target area center first, Obtain the corresponding respiratory phase in four-dimensional image model；Then basisPhase corresponding with two neighboring 3-D view away from From determination interpolation weights；Finally using motion vector field between this two groups of 3-D views to carrying out deformation conversion with reference to phase, Finally give and be used for 3-D view corresponding to the treatment subarc.

Dose assessment module is tired out using dose reconstruction interpretation of result patient care plan dosage with interval procedure dosage, multiple gradation Add the difference between dosage；Including dosage map submodule and dosage analysis submodule：a）Dosage map submodule utilizes image Deformation vectors field between plan CT images and CBCT images that registration module obtains, the gradation agent that dose reconstruction module is calculated Amount field is mapped under plan CT image coordinate systems, obtains mapping dosage field by several times；Counted using the mapping dosage field of multiple gradation Dosage is born in the accumulation for calculating patient, for compared with intended dose；b）Dosage analysis submodule is to intended dose field and again The irradiation for building related organization under dosage field is analyzed and compared by amount, and treatment plan is adjusted, amendment patient it is actual by The deviation that amount and plan are measured；QA is carried out to system by comparing the intended dose of die body plan and rebuilding dosage（Quality is protected Card）；The function of offer includes：The contrast of isodose, isodose surface shows, DVH（Dose volume histogram）Contrast show, The contrast of section dosage is shown and difference is shown, dosage field 3D Gamma（Gamma）Analysis.

It is as follows that the dosage verifying system of the radiotherapy unit of this example is used for the step of online dosage verifying：

A) each related organization is directed to, structure includes the three-dimensional masking-out image of the tissue in space；Masking-out image In the value of each voxel represent profile containment relationship, when the voxel be located inside occluding contour, value is 1；When the voxel Value is 0 when outside occluding contour；

B) the three-dimensional equivalent surface model for being 1 using Marching Cube isosurface extractions method extraction voxel value；

C) the deformation vectors field obtained using step A, line translation is entered to each summit of three-dimensional equivalent surface model, obtained Three-D profile surface model after deformation；

D) target 3D CBCT each layer of two-dimentional axle position image is directed to, utilizes the plane being coincide with the two-dimensional image position Cutting is carried out to the three-dimensional equivalent surface model after deformation, obtains point that 3 d surface model intersects with the plane or coincidence Straight line；These points and straight line are attached in sequence, obtain the wheel organized after the deformation corresponding to the two-dimentional axle position image Profile；

E) contour line on all two-dimentional axle position images of integration objective 3D CBCT, as maps obtained trouble by profile The online tissue contours information of person；

C. 3D CBCT images are calculated and have recorded every in 3D CBCT to the deformation vectors field of plan CT images, deformation vectors field A bitP _iThe deformation vectors of corresponding points into plan CT；Using the HU values and the transformational relation of electron density for planning CT, according to 3D The HU values of each voxels of CBCT corresponding position in CT is planned calculate the electron density of the voxel, so as to obtain 3D CBCT figures The organizing electronic density map as corresponding to；When calculating deformation vectors field, the plan CT images that are obtained first to step A to the 3D The deformation vectors field of CBCT imagesDFCarry out inversion calculation；Then it is used as initial value by the use of method for registering images using the conversion of inverting It is intended to CT and is registrated to 3D CBCT, obtains 3D CBCT images to the accurate deformation vectors fields of plan CT；

E. the multiple fractionation of radiations of patient are carried out using the 3D CBCT images of different gradation collection and the exposure dose of calculating The deformation of dosage adds up；The deformation of exposure dose is cumulative to need to choose a certain group of image as reference picture, wherein reference picture For the plan CT or 3D CBCT of any collection by several times；When deformation adds up, first with deformation vectors field computation reference picture Correspondence position of each voxel in other gradation 3D CBCT images, and obtain the opening position using cubic interpolation method Dosage, finally added up to obtain the deformation cumulative dose at some voxel location to the dosage that interpolation obtains；

The dosage verifying system of the radiotherapy unit of this example to contain movable information dose reconstruction the step of it is as follows：

A) registration two-by-two is carried out according to the order of respiratory phase to each group 3-D view in 4D CBCT, obtains two adjacent groups Deformation vectors field between 3-D view；

B) each group deformation vectors fields is comprehensively utilized, the features such as according to respirometric continuity, periodicity, builds B-spline Motion model or the motion model based on PCA, improve the degree of accuracy of movable information；

A) non-rigid body model method is utilized to plan CT, to be planned each group of 3D CBCT image registrations in 4D CBCT CT to 3D CBCT deformation vectors field, wherein deformation vectors field have recorded every bit in plan CTP _iInto each group of 3D CBCT The deformation vectors of corresponding points；

B) the related organization's profile being intended to using above-mentioned deformation vectors field on CT is mapped on each group of 3D CBCT, is obtained To the online tissue contours information of patient；

C. each group of 3D CBCT image is calculated in 4D CBCT to the deformation vectors field for planning CT, wherein deformation vectors script holder Every bit in 3D CBCT is recordedP _iThe deformation vectors of corresponding points into plan CT；Turned using the HU values for planning CT with electron density Relation is changed, the electron density of the voxel is calculated according to the HU values of each voxels of 3D CBCT corresponding position in CT is planned, so as to Finally give organizing electronic density map corresponding to each group of 3D CBCT image in 4D CBCT；Calculate each group of 3D CBCT image To plan CT deformation vectors field when, the plan CT images that are obtained first to step B to the deformation vectors field of the 3D CBCT images Inversion calculation is carried out, being then intended to CT as initial value using the conversion of inverting by the use of method for registering images is registrated to 3D CBCT, 3D CBCT images are obtained to plan CT accurate deformation vectors field；

A) it is directed to each launched field B_i, from treatment journal file in analysis obtain dynamic tracing motion target area treated when The movement locus and range of movement of collimater, and movement locus is divided into N number of subsegment of equidistant intervals, wherein N can be by doctor Selected as needed；

B) position at target area center at each subsegment mean place is obtained according to treatment journal file, and according to target area center Position three-dimensional CT images data I corresponding to interpolation acquisition from 4D iconic models_iWith organizing electronic density map；

ii.Correspondence position of the target area center on the central motion curve of target area at each subsegment mean place is calculated, Determine patient respiratory phase corresponding to current subsegmentt；

C) image I is utilized_iThe collimater dosage that patient bears when the subsegment is moved is calculated, wherein Rapid Dose Calculation MU numbers are Dosage goes out beam MU sums in the subsegment during collimater back and forth movement tracking target area；

D) above method is utilized, respectively to projection B_iEach subsegment carry out above-mentioned Rapid Dose Calculation, obtain the three-dimensional agent of N groups Measure field D_i, a certain group of image is then selected as reference picture, to N group 3-dimensional doses field D_iDeformation is carried out to add up；Reference picture can To be that plan CT either a certain group of 3D CBCT or carries out deformation on multigroup reference picture and added up in 4D CBCT；

E) and then for all launched fields carry out above-mentioned Rapid Dose Calculation, add up, finally give the dosage field of whole treatment plan；

The dosage verifying system of the radiotherapy unit of this example is used for the dosage weight of image-guided stereotactic surgery/radiotherapy The step of building is as follows：

A. the journal file of therapeutic process is analyzed, according to patient body position's situation of change in therapeutic process by whole therapeutic process It is divided into multiple treatment stages：

A) incipient stage is treated, gathers the 3D CBCT images CBCT of patient₀, by CBCT₀Registration is carried out with plan CT Start therapeutic process after implementing the initial pendulum position of patient；

B) therapeutic process journal file is analyzed, a patient body position often occurs and changes the treatment then terminated on last stage Journey, start a new treatment stage.If treatment journal file have recorded n times position chanP, then whole therapeutic process will It is divided into+1 treatment stage of N.If if patient body position does not change over the course for the treatment of, then an only treatment rank Section；

B. the journal file of therapeutic process is analyzed, obtains patient's CBCT numbers required for each treatment stage dose reconstruction According to：

A) it is corresponding to start treatment stage, use initial pendulum position image CBCT₀Carry out dose reconstruction；

If b) patient body position's change can extent of amendment beyond system, then needs to be put position again to patient.Put again After position, system obtains image CBCT using pendulum position again_iCarry out dose reconstruction；

C) if patient body position changes and can be in extent of amendment over the course for the treatment of, then according to treatment daily record text The CBCT data CBCT that the position chanP amount of part record obtains to last pendulum position_iRigid Body In Space conversion is carried out, utilization space becomes CBCT after changing_iCarry out dose reconstruction；

C. the journal file of therapeutic process is analyzed, obtains the launched field information in each treatment stage, and obtain using step 2 Corresponding CBCT carry out dose reconstruction（The method for not limiting CBCT Rapid Dose Calculations）.

D. CBCT is corresponded to according to each treatment stage and plans the rigid body translation between CT, the dosage under CBCT spaces is reflected It is mapped to progress dosage under plan CT coordinate systems to add up, obtains the dose reconstruction result of whole treatment stage.

E. intended dose is compared using gamma analysis and dose-volume histogram method and rebuilds dosage；Can be relatively more single The intended dose and reconstruction dosage of individual gradation；Or the cumulative dose of more multiple gradation intended doses and the weight of multiple gradation Build cumulative dose of dosage etc..

Embodiment two

The dosage verifying system of the radiotherapy unit of this example, applicable radiotherapy unit are that a kind of radiation of robot is controlled Device is treated, the robot radiation therapy device is by robot arm, radiographic source, numerical control therapeutic bed, respiratory movement tracking system System, C arm real-time imagings system, 4D radiotherapy treatment planning systems and dosage verifying system composition, the robot arm, ray Between source, numerical control therapeutic bed, respiratory movement tracing system, C arm real-time imagings system, treatment planning systems and dosage verifying system Telecommunication connects.The radiographic source is arranged on robot system end, for being irradiated to target area；The numerical control therapeutic bed phase Installed for robot system, for being supported and positioning to patient；The 4D radiotherapy treatment planning systems, comprising just reverse Radiotherapy treatment planning, for carrying out plan to Case treatment.

C arms real-time imaging system described in this example is single flat planar image system, for carrying out real time imagery to patient target area, its It is made up of C arms slide rail, the rotating shaft of C arms, base and x-ray source, x-ray detector installed in C arm slide rails both ends；X-ray source can be 150KV, C arm slide rail guide x-ray source and X-ray detector to make to be more than 180 ° of motions, carry out the CBCT of patient target area（Pencil-beam Volume is imaged）Imaging combines the progress target area 4D CBCT imagings of respiratory movement tracing system, for target area real-time tracing and dosage Checking system carries out dose reconstruction and checking.

Remaining is the same as embodiment one.

Embodiment three

The dosage verifying system of the radiotherapy unit of this example, applicable radiotherapy unit are the Truebeam of Varian Radiotherapy unit, the Truebeam radiotherapy units hardware components include rotary frame, electron linear accelerator, X and penetrated Line image system, EPID（Electronic portal image device）And therapeutic bed.The electron linear accelerator is installed on rotary frame End；The X ray image system, including X ray bulb and flat panel detector, it is opposed to be installed in the middle part of rotary frame；It is described EPID（Electronic portal image device）, it is opposed with electron linear accelerator to be installed on rotary frame bottom.Software systems include holding Product adjusts strong arc therapy planning system, breathes dynamic door control system and integrated control operation system.X ray image system in this example System can carry out CBCT imagings with the rotation of rotary frame, and then carry out patient's pendulum position, dynamic target area with CBCT is image-guided Tracking and real-time dosage verifying.

The dosage verifying system of this example is the same as embodiment one.

Claims

1. the dosage verifying system of a kind of radiotherapy unit, it is characterised in that dosage verifying system is mainly by data transfer mould Block, image registration module, profile mapping block, tissue change analysis module, four-dimensional image modeling module, dose reconstruction module and Dose assessment module forms, wherein, data transmission module is connected with data server, and data transmission module is also matched somebody with somebody with image respectively Quasi-mode block, profile mapping block, four-dimensional image modeling module are connected with dose reconstruction module；Image registration module respectively with profile Mapping block, four-dimensional image modeling module are connected with dose assessment module；Profile mapping block is through patient's online tissue contours point It is not connected with tissue change analysis module and dose assessment module；Tissue change analysis module is put with data transmission module and the four-dimension Treatment planning systems are penetrated to be connected；Four-dimensional image modeling module is connected with dose reconstruction module；Dose reconstruction module and dose assessment Module is connected；Dose assessment module is connected with data transmission module and Four dimensional radiotherapy planning system；The profile maps mould Deformation vectors between plan CT and online CBCT images that block is provided using planning contours information, the Registration of Measuring Data module of patient , calculate mapping of the planning contours to CBCT images；After being modified to profile mapping result, obtain patient and organize to take turns online It is wide；Profile mapping block includes following submodule：a）Three-dimensional grid builds submodule：According to tissue three-dimensional contour line, structure group The three-dimensional grid surface model knitted；Specially：Go out the three-dimensional grid of tissue first with the initial three-dimensional profile reconstruction of tissue Surface, then using Deformation Field interpolation technique, each three-dimensional grid apex is obtained from the deformation vectors field that registration obtains Deformation vectors, and coordinate transform is carried out to grid vertex, obtain the three-dimensional grid surface under profile mapping objects image coordinate system Model；b）Three-dimensional module cutting submodule：The three-dimensional gone out using the three-dimensional grid surface model cutting after deformation on arbitrary plane Contour line；Specially：According to target image cut into slices where plane, to three-dimensional grid surface model carry out cutting, calculate cutting with The slice location of each three-dimensional grid, and by connecting grid cutting point in order, obtain corresponding contour line；c）Profile distance becomes Change submodule：Its corresponding three-dimensional distance figure is obtained using tissue three-dimensional contour line；Specially：First according to original contour line meter Profile binary map and profile distance map are calculated, the image coordinate system of profile distance map is consistent with the image for sketching outline line, Voxel value in range image positioned at contoured interior is just, the voxel value of profile exterior is negative, and its absolute value is the voxel to three Tie up the minimum distance of contour surface；Then deformation conversion is carried out to three-dimensional distance figure using deformation vectors field, obtains profile mapping Profile distance map under target image space coordinates；Finally extract the equivalence that pixel value is 0 on each faultage image in distance map Line, the isopleth are the mapping result of three-dimensional contour line.

2. the dosage verifying system of radiotherapy unit according to claim 1, it is characterised in that the data transfer mould Block is communicated by network connection with data server, obtains the related data needed for dosage verifying, by the result storage to number According to server.

3. the dosage verifying system of radiotherapy unit according to claim 1, it is characterised in that described image matches somebody with somebody quasi-mode Block provides rigid body and deformable registration method, for four-dimensional CT/CBCT differences respiratory phase graphics in four-dimensional image modeling module The registration of picture；For planning the deformable registration of CT images and CBCT images in profile mapping block.

4. the dosage verifying system of radiotherapy unit according to claim 1, it is characterised in that the tissue change point Analysis module by quantitative comparison patient care plan profile and the online tissue contours of patient come analyze histoorgan position, volume and The change of vpg connection, and the online tissue contours of patient are saved in by data server by data transmission module；Can also be simultaneously The form in multiple gradation undertissues is checked and analyzes, it is directly perceived to show tissue with the situation of change of therapeutic process.

5. the dosage verifying system of radiotherapy unit according to claim 1, it is characterised in that the four-dimensional image is built Mould module utilizes the deformation vectors field between the four-dimensional CT images difference phase that image registration module provides, and establishes the four-dimension of patient Iconic model；Mainly include image registration and four-dimensional movement models two submodules：a）Image registration submodule is to 4DCT/ Each group 3-D view is carried out registering two-by-two according to the order of respiratory phase in 4DCBCT, is obtained between two adjacent groups 3-D view Deformation vectors field；b）The each group deformation vectors field that four-dimensional movement modeling submodule comprehensive utilization image registration submodule obtains, according to According to respirometric continuity, periodic characteristics, B-spline motion model or the motion model based on principal component analysis are built, So as to improve the degree of accuracy of movable information.

6. the dosage verifying system of radiotherapy unit according to claim 1, it is characterised in that the dose reconstruction mould Block goes out the dosage that current gradation patient bears using four-dimensional image model or three-dimensional CBCT image reconstructions, and it is close mainly to include electronics Scale stator modules and Rapid Dose Calculation submodule：

a）Electron density demarcates submodule by by CBCT image registrations to plan CT images, obtaining voxel in CBCT images Correspondence position on plan CT images, then utilizeThe HU values at place replace voxel in CBCT imagesThe HU values at place, finally The HU images for generating one group of simulation are used for determination and the Rapid Dose Calculation of organizing electronic density；

b）Rapid Dose Calculation submodule carries out Rapid Dose Calculation based on the CBCT for having demarcated electron density, and patient is in interval procedure for estimation The dosage actually received；

Rebuild for the fractionated dose of static target area, Rapid Dose Calculation submodule considers patient body position in therapeutic process and changes docking Influenceed by dosage；

Rebuild for the fractionated dose for moving target area, Rapid Dose Calculation submodule considers target area and other related organizations were treating Actual motion situation, the situation of target area tracking treatment in journey, so as to estimate more accurately patient's acceptable dose, it is specially： For each launched field, the movement locus and fortune of collimater when analysis is directed to each launched field motion compensation from therapeutic process file Scope is moved, and movement locus is divided into N number of subarc of equidistant intervals；Obtain the position at target area center at each subarc mean place Put, and the 3 d image data according to corresponding to the interpolation acquisition from four-dimensional image model of target area center, finally according to the number According to progress Rapid Dose Calculation；The radiation exposure machine hop count of each subarc, during coming and going multiple periodic motions for treatment head, at this Hop count sum between subarc；By carrying out above-mentioned Rapid Dose Calculation flow to each subarc respectively, N group 3-dimensional doses field is obtained, It is rightIt is weighted summation and obtains the 3-dimensional dose field for each launched field；Then above-mentioned dosimeter is carried out for all launched fields Calculate, be cumulative, finally giving the dosage field of whole treatment plan；Wherein, it is three-dimensional corresponding to interpolation acquisition from four-dimensional image model The operating process of view data is：Row interpolation is entered to target area four-dimensional movement model according to target area center first, obtained four Tie up corresponding respiratory phase in iconic model；Then basisThe distance of phase corresponding with two neighboring 3-D view determines to insert It is worth weight；Finally finally given using motion vector field between this two groups of 3-D views to carrying out deformation conversion with reference to phase For 3-D view corresponding to the treatment subarc.

7. the dosage verifying system of radiotherapy unit according to claim 1, it is characterised in that the dose assessment mould Block utilizes the difference between dose reconstruction interpretation of result patient care plan dosage and interval procedure dosage, multiple gradation cumulative doses； Including dosage map submodule and dosage analysis submodule：a）Dosage map submodule utilizes the plan that image registration module obtains Deformation vectors field between CT images and CBCT images, the fractionated dose field that dose reconstruction module calculates is mapped to plan CT figures As under coordinate system, obtaining mapping dosage field by several times；Using the mapping dosage field of multiple gradation agent is born to calculate the accumulation of patient Amount, for compared with intended dose；b）Dosage analysis submodule is to intended dose field and rebuilds related organization under dosage field Irradiation analyzed and compared by amount, treatment plan is adjusted, amendment patient is actual by amount and the deviation planning to be measured； Quality assurance is carried out to system by comparing the intended dose of die body plan and rebuilding dosage；The function of offer includes：Deng agent The contrast of amount line, isodose surface shows that the contrast of dose volume histogram is shown, the contrast of section dosage is shown and difference shows Show, the analysis of dosage field 3D gammas.

8. the dosage verifying system of radiotherapy unit according to claim 1, it is characterised in that the radiotherapy dress It is as follows that the dosage verifying system put is used for the step of online dosage verifying：

A. deformable registration method is utilized, to plan CT, to obtain planning CT to 3D by the 3D CBCT image registrations for putting position for patient CBCT deformation vectors field, wherein deformation vectors field have recorded every bit in plan CTP _iThe deformation of corresponding points into 3D CBCT Vector；

B. the related organization's profile being intended to using above-mentioned deformation vectors field on CT is mapped on 3D CBCT, and it is online to obtain patient Tissue contours information：

a）For each related organization, structure includes the three-dimensional masking-out image of the tissue in space；It is every in masking-out image The value of one voxel represents profile containment relationship, and when the voxel is located inside occluding contour, value is 1；When the voxel is located at Value is 0 when outside occluding contour；

b）The three-dimensional equivalent surface model for being 1 using isosurface extraction method extraction voxel value；

c）The deformation vectors field obtained using step A, line translation is entered to each summit of three-dimensional equivalent surface model, obtains deformation Three-D profile surface model afterwards；

d）For target 3D CBCT each layer of two-dimentional axle position image, using the plane being coincide with the two-dimensional image position to shape Three-dimensional equivalent surface model after change carries out cutting, obtains the straight of point that 3 d surface model intersects with the plane or coincidence Line；These points and straight line are attached in sequence, obtain the profile organized after the deformation corresponding to the two-dimentional axle position image Line；

e）Contour line on all two-dimentional axle position images of integration objective 3D CBCT, the patient for as mapping to obtain by profile exist Line tissue contours information；

C. 3D CBCT images are calculated to the deformation vectors field of plan CT images, deformation vectors field have recorded each in 3D CBCT PointP _iThe deformation vectors of corresponding points into plan CT；Using the HU values and the transformational relation of electron density for planning CT, according to 3D The HU values of each voxels of CBCT corresponding position in CT is planned calculate the electron density of the voxel, so as to obtain 3D CBCT figures The organizing electronic density map as corresponding to；When calculating deformation vectors field, the plan CT images that are obtained first to step A to the 3D The deformation vectors field of CBCT imagesDFCarry out inversion calculation；Then by the use of method for registering images using the conversion of inverting as initially Value, is intended to CT and is registrated to 3D CBCT, obtains 3D CBCT images to the accurate deformation vectors fields of plan CT；

E. the multiple fractionation of radiation agent of patient are carried out using the 3D CBCT images of different gradation collection and the exposure dose of calculating The deformation of amount adds up；The deformation of exposure dose is cumulative need to choose a certain group of image be as reference picture, wherein reference picture Plan the CT or 3D CBCT of any collection by several times；When deformation adds up, first with every in deformation vectors field computation reference picture Correspondence position of one voxel in other gradation 3D CBCT images, and obtain using cubic interpolation method the agent of the opening position Amount, finally adds up to the dosage that interpolation obtains, obtains the deformation cumulative dose at some voxel location；

F. the Geometrical change situation of quantitative analysis related organization and the exposure dose change being induced by it；Geometrical change includes group Knit change, the coincidence factor in change front and rear profile region of volume and position of centre of gravity；For the analysis of exposure dose change, Ke Yifen Analyse the situation of change of single fractionation of radiation dosage and multiple gradation cumulative doses；The change of dosage is born maximum, most including tissue The change of small, average, median dose and dose-volume relation；Consider the tissue change situation of multiple gradation, calculate each Item index is with the change curve and rate of change of interval procedure.

9. the dosage verifying system of radiotherapy unit according to claim 1, it is characterised in that the radiotherapy dress The dosage verifying system put to contain movable information dose reconstruction the step of it is as follows：

A. the four-dimensional image model for including histokinesis's information is established using 4D CBCT data；Four-dimensional image model includes difference Multigroup three-dimensional CBCT under respiratory phase and it is different when alternate histoorgan movable information；

a）Registration two-by-two is carried out according to the order of respiratory phase to each group 3-D view in 4D CBCT, obtains two adjacent groups three-dimensional Deformation vectors field between image；

b）Each group deformation vectors fields is comprehensively utilized, the features such as according to respirometric continuity, periodicity, structure B-spline motion Model or the motion model based on principal component analysis, improve the degree of accuracy of movable information；

a）Using non-rigid body model method by each group of 3D CBCT image registrations in 4D CBCT to CT is planned, obtain plan CT and arrive 3D CBCT deformation vectors field, wherein deformation vectors field have recorded every bit in plan CTP _iIt is corresponding into each group of 3D CBCT The deformation vectors of point；

b）The related organization's profile being intended to using above-mentioned deformation vectors field on CT is mapped on each group of 3D CBCT, is suffered from The online tissue contours information of person；

C. each group of 3D CBCT image in 4D CBCT is calculated to record to plan CT deformation vectors field, wherein deformation vectors script holder Every bit in 3D CBCTP _iThe deformation vectors of corresponding points into plan CT；Changed using the HU values for planning CT with electron density Relation, the electron density of the voxel is calculated according to the HU values of each voxels of 3D CBCT corresponding position in CT is planned, so as to most Organizing electronic density map corresponding to each group of 3D CBCT image in 4D CBCT is obtained eventually；Each group of 3D CBCT image is calculated to arrive When planning CT deformation vectors field, the deformation vectors field of the plan CT images to the 3D CBCT images that are obtained first to step B is entered Row inversion calculation, then invert and converted as initial value by the use of method for registering images using this, be intended to CT and be registrated to 3D CBCT, 3D CBCT images are obtained to plan CT accurate deformation vectors field；

D. according to the treatment journal file recorded in therapeutic process, the checking dosage for including motion tumour tracked information is calculated：

a）For each launched field B_i, analyzed from treatment journal file and obtain collimating when dynamic tracing motion target area is treated The movement locus and range of movement of device, and movement locus is divided into N number of subsegment of equidistant intervals；

b）The position at target area center at each subsegment mean place is obtained according to treatment journal file, and according to target area center The interpolation from 4D iconic models, three-dimensional CT images data I corresponding to acquisition_iWith organizing electronic density map；

I. the target area contour line on each group of 3D CBCT obtained according to step B, is calculated with patient respiratory phase target area center The curve movement of position；

Iii. found out from 4D CBCT and patient respiratory phasetTwo groups of adjacent 3D CBCT, it is respectivelyt _iWitht _j, whereint _i≤ t _≤ t _j；According to the position relationship of respiratory phase, using linear interpolation method, from organizing electronic density map corresponding to two groups of 3D CBCT Interpolation, obtain three-dimensional CT images data I corresponding to the treatment subsegment_iWith organizing electronic density map；

c）Utilize image I_iCalculate the collimater dosage that patient bears when the subsegment is moved, wherein Rapid Dose Calculation radiation exposure machine Device hop count is dosage goes out beam line irradiation machine hop count sum in the subsegment during collimater back and forth movement tracking target area；

d）Using the above method, respectively to projection B_iEach subsegment carry out above-mentioned Rapid Dose Calculation, obtain N group 3-dimensional doses field D_i, a certain group of image is then selected as reference picture, to N group 3-dimensional doses field D_iDeformation is carried out to add up；Reference picture can be Plan CT either a certain group of 3D CBCT or carries out deformation on multigroup reference picture and added up in 4D CBCT；

e）Then carry out above-mentioned Rapid Dose Calculation for all launched fields, add up, finally give the dosage field of whole treatment plan；

E. using gamma analysis and dose-volume histogram method, that compares related organization under different situations bears dosage, and carries For a variety of quantitative analytical datas, to determine the need for carrying out Plan rescheduling；The intended dose of more single gradation and deformation are tired out Add dosage；Or the cumulative dose of more multiple gradation intended doses, and the cumulative agent of the deformation cumulative dose of multiple gradation Amount.