CN117653936A

CN117653936A - Quality control detection die body for stereotactic radiotherapy and use method

Info

Publication number: CN117653936A
Application number: CN202410092935.0A
Authority: CN
Inventors: 牛静; 张沐天; 付宁
Original assignee: Jiangsu Ruier Medical Science & Technology Co ltd
Current assignee: Jiangsu Ruier Medical Science & Technology Co ltd
Priority date: 2024-01-23
Filing date: 2024-01-23
Publication date: 2024-03-08

Abstract

The invention relates to a quality control detection die body for stereotactic radiotherapy and a detection method, which belong to the technical field of radiotherapy. The quality control detection die body comprises a plurality of die body pieces, and the die body pieces are combined to obtain the quality control detection die body; when the die body pieces are used, the die body pieces are sequentially connected from top to bottom.

Description

Quality control detection die body for stereotactic radiotherapy and use method

Technical Field

The invention relates to the technical field of radiotherapy, in particular to a quality control detection die body for stereotactic radiotherapy and a use method thereof.

Background

Stereotactic Radiation Therapy (SRT) is an accurate radiation therapy technique. It uses a high energy beam to locate and irradiate the tumor to minimize damage to surrounding normal tissue. Stereotactic radiation therapy was applied to the treatment of intracranial and deep tumors in the early 50 s of the 20 th century. With the continuous development of computer technology and imaging technology, the technology is further improved and promoted, and is applied to the treatment of various tumors, mainly including intracranial tumors, head and neck tumors, lung cancer, liver cancer, pancreatic cancer, prostate cancer, spinal tumor and the like.

With the continuous progress of tumor radiotherapy technology and the rapid development of computer technology, radiophysics, radiobiology, imaging and functional imaging, tumor radiotherapy technology has been revolutionarily developed. Precision radiotherapy plays an increasingly important role in the comprehensive treatment of tumors, so that quality control of stereotactic radiotherapy SRT is important in order to ensure the accuracy of patient treatment. Among the quality control related items, quality control items related to the stereotactic radiotherapy SRT mainly comprise dosimetry verification, mechanical precision verification, image guiding verification, system performance verification and the like, except for the dosimetry verification which is provided with a commercial standard instrument, the verification of other items is not provided with a unified standard detection die body, and the detection of the other items is generally available locally, the existing quality control detection die body can only detect a single quality control item and cannot detect a plurality of quality control items at the same time, so that measurement errors are intangibly introduced on one hand, and the working efficiency of clinical staff is not facilitated on the other hand.

In addition, the existing quality control detection die body is a die body with a frame, for example, the Chinese utility models with publication numbers of CN215900764U, CN219539274U and CN209451164U are all die bodies with frames, when rays are incident from the frame positions, the ray paths are changed, verification results are affected, and the size of the die body is large.

Disclosure of Invention

In view of the above problems, the invention provides a quality control detection die body and a detection method for stereotactic radiotherapy, wherein a plurality of quality control projects of stereotactic radiotherapy can be completed by using one complete quality control die body, so that the operation steps are greatly simplified, the installation is convenient, the repeated work of clinical staff is reduced, the working efficiency of the clinical staff is improved, the quality control time can be saved, the accuracy of quality control detection can be improved, the quality control detection die body has a cylindrical structure, the measurement error caused by the change of a ray path is avoided, and the die body has a small volume.

The invention provides a quality control detection die body for stereotactic radiotherapy, which comprises: the plurality of die body pieces are combined according to the quality control function detection requirements of the stereotactic radiotherapy, and corresponding die body pieces are selected to obtain a quality control detection die body;

it can be understood that the material density of the quality control detection die body is similar to the density of water, namely the quality control detection die body is equivalent to the die body of water and is close to a human body;

preferably, the die body pieces are cylinders with equal diameters and comprise two end faces and a curved surface (side face);

When the plurality of die body pieces are used, the centers of the plurality of die body pieces are longitudinally aligned and connected according to the passing of the respective one end face of the die body pieces;

specifically, according to the detection requirement, a plurality of die body pieces are longitudinally and sequentially arranged along the z-axis, and the upper end face and the lower end face of each two die body pieces are contacted. Preferably, the plurality of die body pieces are respectively a first die body piece 1, a second die body piece 2, a third die body piece 3, a fourth die body piece 4, a fifth die body piece 5, a sixth die body piece 6, a seventh die body piece 7 and an eighth die body piece 8; as in fig. 1.

Preferably, the first die body 1 comprises a top surface, a bottom surface and a peripheral wall; the die body piece is used for simulating different depths of tumors in a human body;

the top side of the first peripheral wall is connected with the first top surface, and the bottom side of the first peripheral wall is connected with the first bottom surface;

further, the height of the first peripheral wall is selected according to the depth of the tumor in the human body to be detected;

still further, the height of the peripheral wall one may be 1, 2.5, 7.5 or 17.5cm.

Preferably, the second die body 2 comprises a second top surface, a second bottom surface, a second peripheral wall and a first clamping groove 21; the second die body piece is used for measuring point dose;

the top side of the second peripheral wall is connected with the second top surface, and the bottom side of the second peripheral wall is connected with the second bottom surface; as in fig. 1;

One end of the clamping groove I21 is connected with the outer peripheral wall II, and the other end extends to the inside of the die body part II; the clamping groove is used for placing a finger tip detector;

further, the first clamping groove comprises a first clamping groove surface and a clamping groove wall; as in fig. 1;

one end of the clamping groove wall penetrates through the wall surface of the second peripheral wall; the other end of the clamping groove wall is connected with a clamping groove surface I; the clamping groove surface I and the clamping groove wall are arranged in the die body part II; as in fig. 1;

furthermore, the proportional relation between the axial length of the slot wall and the two diameters of the top surface is as follows: 1:2; the first clamping groove is arranged according to the size of the finger end detector;

the invention provides the clamping groove for installing the finger end detector, wherein the axial length of the clamping groove is equal to the radius of the die body piece, namely, the probe of the finger end detector is positioned at the center of the die body piece and is used for accurately detecting the dosage of the beam.

Preferably, the third die body piece comprises a third top surface, a third bottom surface, a third peripheral wall and a second clamping groove; the die body piece III is matched with other die body pieces for measuring two-dimensional plane dose;

the top side of the third peripheral wall is connected with the third top surface, and the bottom side of the third peripheral wall is connected with the third bottom surface;

one end of the clamping groove II is connected with the peripheral wall III, and the other end extends to the inside of the die body part III; the extension depth is as shown in fig. 1;

The clamping groove II is used for placing a no-rinse film;

preferably, the mold body piece IV comprises a top surface IV, a bottom surface IV, a peripheral wall IV and a metal marking assembly; the mold body piece IV is matched with a plurality of mold body pieces for image-guided project testing;

the top side of the peripheral wall IV is connected with the top surface IV, and the bottom side is connected with the bottom surface IV; the metal marking component is fixedly arranged in the die body piece IV;

the metal marking assembly includes: a first marker 41, a second marker 42 and a third marker 43;

the second marker is positioned at the center of the fourth die body, the first marker is positioned obliquely above the second marker, the inclination angle is 45 degrees, the third marker is positioned obliquely below the second marker, and the inclination angle is 45 degrees;

further, the first marker 41 and the second marker 42 form a vertical distance H1 and a horizontal distance H2, and the second marker and the third marker form a vertical distance H3 and a horizontal distance H4; as in fig. 3;

the proportional relation between the first vertical interval H1 and the second vertical interval H3 is as follows: 1:1; the proportional relation between the horizontal interval one H2 and the horizontal interval two H4 is as follows: 1:1;

the proportional relation between the vertical interval I and the horizontal interval I is as follows: 1:2; the proportional relation between the vertical interval II and the horizontal interval II is as follows: 1:2;

Further, the first vertical distance and the second vertical distance are 1 cm; and the horizontal distance I and the horizontal distance II are 2 cm.

Preferably, the mold body part five comprises a top surface five, a bottom surface five, a peripheral wall five and a cylinder; the mold body fifth is matched with the plurality of mold body parts for use to evaluate the image center imaging positioning stability of the image positioning guide system IGPS;

the top side of the peripheral wall five is connected with the top surface five, and the bottom side is connected with the bottom surface five; the top surface five is connected with the bottom surface four; the cylinder is arranged in the die body part five; the die body fifth is matched with at least one die body for calculating accuracy by a test system;

further, the center of the cylinder coincides with the center of the die body part five, so that the dose of the isocenter of the die body part five can be conveniently tested; the top surface and the bottom surface of the cylinder are respectively connected with the top surface five and the bottom surface five in a penetrating way; according to the test requirement, replacing cylinders with different densities;

the cylinder is polymethylpentene, low-density polystyrene, polystyrene or polyoxymethylene resin;

still further, the density may be 0.2, 1.8 or 4.5g/cm ³ ；

Preferably, the die body piece six comprises a top surface six, a bottom surface six, a peripheral wall six and a cylinder assembly; the mold body piece six is matched with a plurality of mold body pieces for system performance verification of stereotactic radiotherapy;

The top side of the peripheral wall six is connected with the top surface six, and the bottom side is connected with the bottom surface six; the top surface six is connected with the bottom surface five; the cylinder component is arranged in the die body part six;

further, the cylinder assembly includes: cylinder one 61, cylinder two 62, cylinder three 63 and cylinder four 64;

the first cylinder, the second cylinder, the third cylinder and the fourth cylinder are symmetrically distributed around the center of the die body piece six; according to the test requirement, replacing cylinders with different densities;

still further, the cylinder density may be 0, 0.5, 1 or 1.8g/cm3.

Further, the proportional relation between the heights of the first cylinder, the second cylinder, the third cylinder and the fourth cylinder and the height of the fifth cylinder of the die body part is as follows: 1:1:1:1:5;

the ratio of the height to the diameter of the first cylinder, the second cylinder, the third cylinder and the fourth cylinder is 1:1;

the heights of the first cylinder, the second cylinder, the third cylinder and the fourth cylinder are 1cm;

the diameter of the first cylinder, the second cylinder, the third cylinder and the fourth cylinder is 1cm. Preferably, the die body member 7 includes a top surface seven, a bottom surface seven, a peripheral wall seven and a ball member 71;

The top side of the peripheral wall seven is connected with the top surface seven, and the bottom side is connected with the bottom surface seven; the top surface seven is connected with the bottom surface six; the spherical part is fixedly arranged at the seven central positions of the die body part;

the die body seven is matched with the plurality of die body pieces for use in testing the mechanical precision of the collimator;

further, the spherical member is a sphere, and the material is poly propionic acid; the ratio relation between the diameters of the ball and the die body piece seven is 1:5;

further, the diameter of the sphere is 2 cm.

Preferably, the die body member eight 8 includes a top face eight, a bottom face eight and a peripheral wall eight;

the die body part eight is positioned at the bottom, so that the back scattering of rays is prevented, and measurement errors caused by the back scattering of the rays are avoided; the top side of the peripheral wall eight is connected with the top surface eight, and the bottom side is connected with the bottom surface eight; the top surface eight is connected with the bottom surface seven.

Preferably, the first die body part 1, the second die body part 2, the third die body part 3, the fourth die body part 4, the fifth die body part 5, the sixth die body part 6, the seventh die body part 7 and the eighth die body part 8 are cylinders with equal diameters;

the die body part II 2, the die body part III 3, the die body part IV 4, the die body part V5, the die body part VI 6, the die body part V7 and the die body part V8 are equal in height;

Further, the plurality of die body pieces have a diameter of 10cm; the heights of the second die body part 2, the third die body part 3, the fourth die body part 4, the fifth die body part 5, the sixth die body part 6, the seventh die body part 7 and the eighth die body part 8 are 5cm;

the invention sets a plurality of cylindrical die body pieces with equal heights, and in the quality control detection process, the die body pieces are replaced or quality control items are replaced, thereby ensuring the consistency of tracing and avoiding measurement errors caused by the change of ray paths; the device can measure various parameters, has high precision and strong modularization, and a plurality of die body piece layers can be flexibly combined; the quality control detection die body has the advantages of wide application range, capability of greatly improving the working efficiency of quality control personnel, simple structure and convenience in operation and carrying. Further, the ratio of the diameters and the heights of the first die body part 1, the second die body part 2, the third die body part 3, the fourth die body part 4, the fifth die body part 5, the sixth die body part 6, the seventh die body part 7 and the eighth die body part 8 is 2:1.

The invention further provides a using method of the quality control detection die body for stereotactic radiotherapy, and the quality control detection die body is used for detecting multifunctional items;

preferably, the quality control detection die body is used for carrying out dosimetry verification, mechanical precision verification, software performance verification, image guidance and system performance verification;

Further, the first die body part 1, the second die body part 2, the third die body part 3, the fourth die body part 4, the fifth die body part 5, the sixth die body part 6, the seventh die body part 7 and the eighth die body part 8 are sequentially connected with the upper end face and the lower end face of each die body part from top to bottom by taking a z axis as a center, so that a quality control detection die body is obtained;

in one embodiment of the present invention, the method further comprises the step of performing spot dose verification based on the first die body part 1, the second die body part 2 and the eighth die body part 8, wherein the specific steps comprise:

placing the quality control detection die body on a treatment bed, and adjusting the placement position of the quality control detection die body to be parallel to the horizontal plane;

placing a finger end detector in a clamping groove I of a die body piece II, connecting the finger end detector with a standard dosimeter in an external connection mode, sequentially irradiating the die body piece I, the die body piece II and the die body piece II by using a 60mm linear accelerator, setting the beam output of the linear accelerator to be 200MU, and taking 3 standard dosimeter readings;

and taking an average value of 3 standard dosimeter readings, correcting the average value by using temperature, air pressure and the like, and outputting a linear accelerator point dosage value.

Comparing the point dosage value of the linear accelerator with a point dosage reference value, and judging whether the point dosage detection requirement is met; when the point dosage value of the linear accelerator is less than or equal to the point dosage reference value plus or minus 2 percent, the point dosage detection requirement is met.

In one embodiment of the present invention, the method further comprises the step of evaluating the stability of the linac point dose values at different dose rates based on the first die body part 1, the second die body part 2 and the eighth die body part 8, and the specific steps comprise:

placing a finger tip detector in a clamping groove I of a die body piece II, connecting the finger tip detector with a standard dosimeter externally, selecting a linear accelerator with the beam quantity of 200MU, selecting at least five dose rates, repeatedly irradiating the die body piece I, the die body piece II and the die body piece eight 5 times by the linear accelerator under each dose rate, taking an average value to obtain average readings of each dose, and recording;

preferably, the five-gear dose rate is 200MU/min, 400MU/min, 600MU/min, 800MU/min, 1000MU/min, respectively.

Comparing the average reading of each gear of dose with the output dose reading of the clinical common dose rate of 1000MU/min, and judging whether the stability detection requirements under different dose rates are met; when the stability detection requirements under different dosage rates are that the average dosage reading of each gear is less than or equal to the output dosage reading of 1000MU/min of the clinical common dosage rate plus or minus 2 percent, the stability detection requirements under different dosage rates are met.

In one embodiment of the present invention, the method further comprises the step of evaluating the stability of the X-ray quality of the linac based on the first, second and eighth mold body pieces, the specific steps comprising:

placing a finger end detector in a clamping groove I of a die body piece II, wherein the finger end detector is externally connected with a standard dosimeter;

a 60mm linear accelerator is selected, and the source wheelbase (SAD) of the linear accelerator is fixed to be 800mm for measurement;

fixing an outgoing beam (MU) to irradiate the first die body part, the second die body part and the eighth die body part in a physical mode;

measuring Tissue Phantom Ratios (TPR) at 20cm and 10cm, respectively, for a depth of the phantom; obtaining a tissue die body ratio measurement value with the depth of 20cm and a tissue die body ratio measurement value with the depth of 10 cm;

comparing the tissue die body ratio measured value with the depth of 20cm with the tissue die body ratio measured value with the depth of 10cm with a stability reference value of the radioactive substance, and judging whether the stability detection requirement of the radioactive substance is met;

when the stability detection requirement of the radioactive substance is that the measured value is less than or equal to the stability reference value of the radioactive substance plus or minus 1 percent, the stability detection requirement of the radioactive substance is met.

In one embodiment of the present invention, the method further comprises the step of evaluating the linear accelerator X-ray beam current output factor based on the first, second and eighth mold body pieces, the specific steps comprising:

irradiating the first die body part, the second die body part and the eighth die body part by using a plurality of types of linear accelerators respectively, and acquiring the dose readings of the standard dosimeter for 3 times when the beam output is 200 MU;

taking the average value of the dose readings of the 3 times of standard dosimeters, obtaining the average value of the dose readings corresponding to the linear accelerators of a plurality of models, and recording;

performing normalization processing on a dose reading average value of a 60mm linear accelerator to obtain a plurality of normalized results, performing deviation on the normalized results and an X-ray beam flow output factor reference value to obtain deviation results corresponding to the linear accelerators of a plurality of models, comparing the deviation results with the X-ray beam flow output factor reference value, and judging whether the X-ray beam flow output factor detection requirement is met;

When the deviation result corresponding to the 20mm linear accelerator is less than or equal to X-ray beam flow output factor reference value +/-2%;

when deviation results (excluding 20mm linear accelerator) corresponding to the linear accelerators of the multiple models are less than or equal to + -1% of the X-ray beam flow output factor reference value, the X-ray beam flow output factor detection requirement is met.

In one embodiment of the invention, the evaluation of the radiation field penumbra characteristic of the linac X-ray beam based on the first, third and eighth die body pieces 1, 3 and 8 specifically comprises:

placing the quality control detection die body on the ground, and adjusting the placing position of the quality control detection die body to be parallel to the horizontal plane;

perpendicular to the upper end surface of the first body portion a central axis of the radiation beam of the linac;

placing a no-rinse film in a clamping groove II of the die body part III, and adjusting the distance from the linear accelerator to the center of the no-rinse film to be 80cm;

a 40mm linear accelerator is selected to irradiate the first die body part, the third die body part and the eighth die body part in sequence, so that a film with an irradiation field is obtained; the irradiation dose can enable the irradiated dose of the film to be kept within the optimal linear region of the dose gray curve;

taking out the film with the irradiation field, and marking the irradiation field direction to obtain a marked film; scanning the marked film by using a film scanner to obtain a corresponding image and storing the corresponding image;

Opening the corresponding image by using film analysis software, marking an axis (X axis and Y axis) of the center of an irradiation field in the corresponding image, respectively obtaining an 80% equivalent dose curve at an X axis intersection point and a Y axis intersection point and a 20% equivalent dose curve at a Y axis intersection point, respectively measuring the distance between the 80% equivalent dose curve at the X axis intersection point and the 20% equivalent dose curve at the X axis intersection point, and judging whether the irradiation field in the film meets the irradiation field penumbra characteristic detection requirement of a linear accelerator X ray beam based on the distance;

when the distance is less than or equal to 4mm, the method meets the detection requirement of the half-shadow characteristic of the irradiation field of the X-ray beam of the linear accelerator.

In one embodiment of the invention, the method for evaluating the stability of the symmetry of the radiation field of the linear accelerator X-ray beam and the stability of the flatness of the radiation field of the accelerator X-ray beam based on the first mold body, the third mold body and the eighth mold body comprises the following specific steps:

perpendicular a central axis of the radiation beam of the linac to an upper surface of the die body part one;

a 60mm linear accelerator is selected, the source wheelbase (SAD) of the linear accelerator is fixed to be 800mm, and the first die body part, the third die body part and the eighth die body part are irradiated in sequence;

respectively measuring a beam off-axis curve OCR (optical character) of the die body surface at a position 50mm away from the film position to obtain two beam off-axis curves (OCR) in orthogonal directions;

based on the beam off-axis curves in the two orthogonal directions, obtaining flatness, symmetry and penumbra of the beam by utilizing software analysis, and comparing the flatness, symmetry and penumbra of the beam with corresponding reference values respectively; if the flatness, symmetry and penumbra of the beam are respectively and simultaneously <2%, the detection requirements are met;

obtaining a maximum dose point and a minimum dose point in a radiation field averaging region (80% of the radiation field width range); calculating the ratio of the maximum dose point to the minimum dose point, and evaluating the stability of the flatness of the accelerator X-ray beam radiation field based on the ratio of the maximum dose point to the minimum dose point;

in one embodiment of the invention, mechanical accuracy verification is performed based on the first, third, seventh and eighth die body pieces;

Specifically, the mechanical precision verification includes: evaluating the in-place precision of the collimator and verifying whether the beam laser point and the radiation field center are consistent;

it will be appreciated that the accuracy of the collimator in position is assessed based on the first, seventh and eighth die body pieces, the specific steps comprising:

mounting a film on the upper surface of the first die body part; the center of the film is aligned with the center of the upper surface of the first die body part;

preparing 60mm, 40mm and 10mm linacs;

the beam irradiated by the linear accelerator is adjusted to be vertical to the center of the surface of the first die body piece, so that the center of the linear accelerator is aligned with the center of the metal ball of the seventh die body piece;

irradiating the processed die body piece I, die body piece seven and die body piece eight by using a 60mm linear accelerator, a 40mm linear accelerator and a 10mm linear accelerator respectively to obtain three irradiation points and corresponding three metal mark piece points on a film;

and respectively calculating the deviation of the three irradiation points and the corresponding three metal marker points, wherein the deviation is less than 1mm, and the in-place precision detection requirement of the collimator is met.

It will be appreciated that the specific steps include, based on the first, third and eighth die body pieces, verifying that the beam laser spot and the radiation field center remain coincident:

and taking a piece of film, arranging a hole in the film, inserting the processed film into a clamping groove II of a die body part III, and adjusting the position of a laser auxiliary device, wherein the laser auxiliary device is used for assisting the linear accelerator to a transmitting position.

The position of the linear accelerator is debugged, so that the transmitting hole of the linear accelerator is aligned with the film hole, and the beam emitted by the linear accelerator is vertical to the upper surface of the first die body part of the quality control detection die body;

respectively selecting 20mm or 40mm linear accelerators, wherein the source wheelbase (SAD) of the corresponding fixed linear accelerators is 800mm and 1600mm;

and controlling the linear accelerator to irradiate the processed die body piece I, the die body piece III and the die body piece eight, forming irradiation points on the processed film, and comparing the position deviation of the irradiation points and the film holes, wherein if the position deviation is less than or equal to 0.5mm, the beam laser points and the radiation field centers are consistent with the detection requirement of keeping the beam laser points and the radiation field centers.

In one embodiment of the invention, system performance verification is performed based on die body one 1, die body three 3, die body four 4, die body five 5, die body six 6, and die body eight 8;

Specifically, the system performance verification includes: CT value accuracy, CT image noise, CT value uniformity, CT value linearity, and CT image spatial integrity.

It can be understood that the specific steps of obtaining the accuracy of the CT value, the image noise, the uniformity of the CT value and the linearity of the CT value by using the system performance verification quality control detection module are as follows:

the quality control detection die body is placed on a treatment bed, and four cylinders with different CT values are arranged in a die body part six; setting the difference between CT values of cylinders with different CT values to be more than 100HU;

CT scanning is sequentially carried out on the first die body part 1, the fourth die body part, the sixth die body part 6 and the eighth die body part 8, and image data are obtained;

the image data are imported into a TPS system to obtain CT test images of a mold body part IV and a mold body part six;

selecting a region of interest (ROI) of about 500 pixels in the center of a CT test image of a die body piece six (about one tenth of the die body area);

selecting a contrast scale, calculating an average CT value of the region of interest (ROI) based on the contrast scale, and obtaining a standard deviation; taking the standard deviation as the CT value precision, requiring the deviation of the CT value precision to be +/-5 HU, and calibrating the CT value precision if the standard deviation exceeds the required CT value precision;

dividing the standard deviation by a contrast scale as a measure of noise, testing CT image noise based on the measure of noise;

Taking the directions of 3 points, 6 points, 9 points and 12 points of the clock as references, respectively selecting regions of interest (ROI) with the size of about 500 pixels along the position of about 10mm of the edge of the CT test image of the die body piece six, and respectively measuring the average CT values of the four regions of interest (ROI);

obtaining an average CT value of a region of interest (ROI) in the center of a CT test image of a die body piece six;

respectively calculating the maximum difference value between the average CT value of the four ROIs and the average CT value of the ROIs in the center of the CT test image, and taking the maximum difference value as a measurement value of CT value uniformity;

scanning the die body part six by using a CT instrument to obtain CT images corresponding to the four cylinders;

selecting regions of interest (ROI) with the size of about 100 pixel points from the centers of CT images corresponding to different cylinders respectively to obtain four regions of interest, and measuring the four regions of interest respectively to obtain average CT values corresponding to the four cylinders;

obtaining a standard CT value of a CT scanner;

calculating the difference value between the average CT value corresponding to the four cylinders and the standard CT value, and recording the maximum difference value as an evaluation parameter of the linearity of the CT value of the quality control detection die body; when the evaluation parameter of the CT value linearity of the quality control detection die body is 60HU, the CT value uniformity detection requirement is met:

And testing the space integrity of the CT image based on the CT test image of the fourth acquired body part.

In one embodiment of the invention, the method further comprises the step of evaluating rotational concentricity of the treatment couch based on the first, fourth and eighth mold bodies, including the steps of:

a quality control detection die body is used for manufacturing a set of treatment plan, and a treatment plan DRR image corresponding to the metal marker is generated according to the treatment plan;

placing the quality control detection die body at the isocenter of the treatment bed, and adjusting the placement position of the quality control detection die body to be parallel to the horizontal plane;

rotating the treatment bed with the quality control detection die body around a central shaft by a plurality of angles, acquiring quality control detection die body image data corresponding to the plurality of angles based on an image guiding system, and comparing the DRR image corresponding to the metal mark in the die body part IV with the position deviation of the quality control detection die body image data corresponding to the plurality of angles, wherein when the position deviation is less than or equal to a position reference value +/-1 mm, the detection requirement is met;

in one embodiment of the present invention, the method further comprises: performing image guidance verification based on the first die body part 1, the fourth die body part 4, the sixth die body part 6 and the eighth die body part 8;

specifically, the image guidance verification includes: evaluating the tracking consistency of the target area positioning system, wherein the method comprises the following specific steps of:

a. Placing a quality control detection die body on a treatment bed, sequentially performing CT scanning on the first die body part 1, the fourth die body part 4 and the eighth die body part 8, obtaining CT scanning images (the thickness of a scanning layer is not more than 1.25 mm), and introducing the CT scanning images into a TPS system of a treatment planning system;

b. creating a treatment plan in a treatment planning system TPS system and saving as an executable plan, generating digitally reconstructed radiological image (DRR) images;

c. in QA mode, a transition is made to the treatment delivery interface through a series of user interface windows. Repositioning the phantom to bring the six degree of freedom couch bias to approximately zero;

d. using the treatment bed movement function of the treatment execution interface, translating or rotating the quality control detection die body by a plurality of different positions and recording to obtain a plurality of moving actual values;

e. using an image guidance system for exposure at each position, comparing the acquired real-time image with a digitally reconstructed radiological image (DRR) image, and recording target positioning system displacement estimated values, i.e. treatment couch corrected values at a plurality of corresponding positions displayed on a treatment execution interface;

comparing the treatment bed correction values at the corresponding positions with the actual values of the movements, and recording deviation; deviation of the treatment couch correction from the actual value of movement: and when the length is less than or equal to +/-2.0 mm, the method meets the requirement of consistency detection of tracking of a target area positioning system.

In another embodiment of the present invention, after the detecting of the plurality of items, performing system performance verification based on the first mold body piece, the second mold body piece, the third mold body piece and the eighth mold body piece;

in particular, the system performance verification includes evaluating the compliance of the calculated dose with the measured dose in a Treatment Planning System (TPS) and performing a patient-specific treatment DQA plan;

it can be understood that the second die body part after the dosimetry verification is inserted into the finger tip ionization chamber, and the first die body part, the second die body part after the verification and the eighth die body part are subjected to CT scanning to obtain CT scanning images, wherein the scanning layer thickness is not more than 1.25mm;

importing the CT scan image into a Treatment Planning System (TPS) to obtain a planned dose;

placing the quality control detection die body on a treatment bed by taking the wall surface as a horizontal plane, executing a radiotherapy plan, and measuring the actual absorbed dose by using an external standard dosimeter;

calculating the planned dose and the actual dose to obtain deviation, and if the deviation is less than or equal to +/-5%, conforming to the detection requirement;

the patient specific therapy test DQA comprises the specific steps of:

creating a patient specific treatment template plan QA based on the CT scan image;

importing the CT scan image into a Treatment Planning System (TPS) to create a patient treatment plan;

Creating a patient-specific treatment plan based on the patient-specific treatment template plan QA; setting executable patient specific treatment fractions;

placing a film in a die body part III subjected to mechanical precision verification, software performance verification and image guidance verification, and performing CT scanning on the die body part I, the die body part III subjected to film placement and the die body part eight according to a patient specific treatment plan to obtain a patient specific treatment plan film;

analyzing the patient specific treatment plan film, and recording an analysis result; the analysis results include the actual spot dose for the patient-specific treatment.

Compared with the prior art, the invention has at least the following beneficial effects:

(1) The quality control detection die body is similar to a human body, the result obtained in the detection process is similar to the result of detection by using the human body, and the verification of a plurality of quality detection items is finished by using the result, so that the maintenance and correction of related equipment are facilitated;

(2) The quality control detection die body realizes the detection work of the three-dimensional directional radiation system through an independent multifunctional quality control detection die body, saves quality control detection time and reduces the cost generated in actual work;

(3) When the quality control detection die body is used for carrying out actual detection, the working efficiency of staff is improved, the accuracy of quality control detection is improved, and the reliability of detection results is further improved.

Drawings

The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention.

FIG. 1 is a schematic diagram of a quality control detection module according to the present invention;

FIG. 2 is a schematic diagram of a top view of a mold body portion six of a quality control detection mold body according to the present invention;

fig. 3 is a schematic diagram of a front view of a body portion six of a quality control sensing body of the present invention.

Reference numerals illustrate:

one-1, two-2, three-3, four-4, five-5, six-6, seven-7, eight-8, one 21, one-41, two-42 and three-43, one-61, two-62, three-63, four-64 and one-71

Detailed Description

In order that the above-recited objects, features and advantages of the present invention will be more clearly understood, a more particular description of the invention will be rendered by reference to the appended drawings and appended detailed description. It should be noted that, without conflict, the embodiments of the present invention and features in the embodiments may be combined with each other. In addition, the invention may be practiced otherwise than as specifically described and thus the scope of the invention is not limited by the specific embodiments disclosed herein.

In order to illustrate the effectiveness of the method provided by the invention, the technical scheme of the invention is described in detail by a specific embodiment, and the specific implementation steps are as follows:

a quality control detection phantom for stereotactic radiotherapy, comprising:

comprising the following steps: the plurality of die body pieces are combined according to the quality control function detection requirements of the stereotactic radiotherapy, and corresponding die body pieces are selected to obtain a quality control detection die body; the material density of the quality control detection die body is similar to the water density and is close to a human body;

preferably, the die body pieces are all in cylindrical shapes with equal diameters;

when the die body pieces are used, the die body pieces are sequentially connected with each other by taking the z axis as the center according to the sequence from top to bottom.

Preferably, the plurality of die body pieces specifically comprise a first die body piece 1, a second die body piece 2, a third die body piece 3, a fourth die body piece 4, a fifth die body piece 5, a sixth die body piece 6, a seventh die body piece 7 and an eighth die body piece 8; as in fig. 1.

Preferably, the first die body 1 comprises a top surface, a bottom surface and a peripheral wall; the die body piece is used for measuring doses of the beam at different depths;

further, the height of the first peripheral wall is selected according to the depth to be detected;

one end of the first clamping groove penetrates through one side of the second peripheral wall, and the other end of the first clamping groove is positioned in the second die body; a finger end detector is arranged at the other end of the clamping groove to measure the dose of the beam spot;

one side of the clamping groove wall penetrates through one side of the second peripheral wall; the other side of the clamping groove wall is connected with a clamping groove surface I; the clamping groove surface I and the clamping groove wall are arranged in the die body part II; as in fig. 1;

further, the proportional relation between the length of the slot wall and the length of the two diameters of the top surface is as follows: 1:2; the size of the clamping groove surface is set according to the size of the finger tip detector;

Preferably, the third die body piece comprises a third top surface, a third bottom surface, a third peripheral wall and a second clamping groove; the die body part is used for measuring planar two-dimensional dose;

one side of the clamping groove II penetrates through one side of the peripheral wall III, and the other side of the clamping groove II is arranged in the die body part III; as in fig. 1;

the clamping groove II is used for placing a finger-type ionization chamber;

further, the second clamping groove is a cuboid clamping groove, and the cuboid clamping groove vertically penetrates through the left side of the third peripheral wall; comprises a cuboid clamping groove surface and a cuboid clamping groove wall;

the cuboid clamping groove face and the cuboid clamping groove wall are arranged in the die body part III; the left side of the rectangular clamping groove wall penetrates through three sides of the peripheral wall, and the other side of the rectangular clamping groove wall is connected with the rectangular clamping groove surface;

further, the proportional relation between the height and the width of the cuboid clamping groove surface and the length of the cuboid clamping groove wall is as follows: 1:3:4.

Preferably, the mold body piece IV comprises a top surface IV, a bottom surface IV, a peripheral wall IV and a metal marking assembly; the mold body piece four is used for image-guided project testing;

the top side of the peripheral wall IV is connected with the top surface IV, and the bottom side is connected with the bottom surface IV; the metal marking component is arranged in the die body piece IV;

the second marker is positioned in the middle of the fourth die body, the first marker is positioned obliquely above the second marker, the inclination angle is 45 degrees, the third marker is positioned obliquely below the second marker, and the inclination angle is 45 degrees;

further, the first marker and the second marker form a first vertical interval and a first horizontal interval, and the second marker and the third marker form a second vertical interval and a second horizontal interval;

the proportional relation between the first vertical interval and the second vertical interval is as follows: 1:1; the proportional relation between the first horizontal interval and the second horizontal interval is as follows: 1:1;

Preferably, the mold body part five comprises a top surface five, a bottom surface five, a peripheral wall five and a cylinder;

the top side of the peripheral wall five is connected with the top surface five, and the bottom side is connected with the bottom surface five; the top surface five is connected with the bottom surface four; the cylinder is arranged in the die body part five;

the mold body piece five is used for mainly testing the calculation precision of software;

Further, the center of the cylinder coincides with the center of the die body part five, so that the dose at the isocenter position can be conveniently tested; the top surface and the bottom surface of the cylinder are respectively connected with the top surface five and the bottom surface five in a penetrating way; according to the test requirement, replacing cylinders with different densities;

still further, the density may be 0.2, 1.8 or 4.5g/cm ³ ；

Preferably, the die body piece six comprises a top surface six, a bottom surface six, a peripheral wall six and a cylinder assembly;

still further, the cylinder density may be 0, 0.5, 1 or 1.8g/cm3.

The proportional relation between the heights of the first cylinder, the second cylinder, the third cylinder and the fourth cylinder and the height of the fifth cylinder of the die body piece is as follows: 1:1:1:1:5;

Preferably, the die body member 7 includes a top surface seven, a bottom surface seven, a peripheral wall seven and a ball member 71;

the top side of the peripheral wall seven is connected with the top surface seven, and the bottom side is connected with the bottom surface seven; the top surface seven is connected with the bottom surface six; the spherical element is arranged in the die body element seven;

the die body piece seven is used for testing the mechanical precision of the collimator;

further, the spherical member is a sphere, and the material is poly propionic acid; the diameter of the sphere is 2 cm.

the die body part eight is positioned at the bottom and used for preventing the influence of back scattering on dose measurement;

the top side of the peripheral wall eight is connected with the top surface eight, and the bottom side is connected with the bottom surface eight; the top surface eight is connected with the bottom surface seven.

and the second die body part 2, the third die body part 3, the fourth die body part 4, the fifth die body part 5, the sixth die body part 6, the seventh die body part 7 and the eighth die body part 8 are equal in height.

Further, the ratio of the diameters and the heights of the first die body part 1, the second die body part 2, the third die body part 3, the fourth die body part 4, the fifth die body part 5, the sixth die body part 6, the seventh die body part 7 and the eighth die body part 8 is 2:1.

further, the first die body part 1, the second die body part 2, the third die body part 3, the fourth die body part 4, the fifth die body part 5, the sixth die body part 6, the seventh die body part 7 and the eighth die body part 8 are sequentially connected from top to bottom by taking the z axis as the center, so that the quality control detection die body with corresponding functions is obtained;

placing the bottom surface of the quality control detection die body and the treatment bed in parallel on the treatment bed, and determining the placement position of the quality control detection die body by using a front distance pointer;

placing a finger end detector in a clamping groove I of a die body piece II, connecting the finger end ionization chamber with a standard dosimeter, irradiating the finger end detector of the clamping groove I by using a 60mm linear accelerator, setting the beam output of the linear accelerator to be 200MU, and taking 3 standard dosimeter readings;

The 3 standard dosimeter readings are averaged and corrected using temperature, air pressure, etc., to output a linac point dose value.

Comparing the point dosage value of the linear accelerator with a point dosage reference value to determine whether the point dosage detection requirement is met; the point dose detection requirement is that the point dose value of the linear accelerator is less than or equal to the point dose benchmark value plus or minus 2 percent.

In one embodiment of the present invention, the method further comprises the specific step of evaluating the stability of the linac point dose values at different dose rates based on the first, second and eighth die pieces, comprising:

at least selecting five-gear dose rate, wherein the beam output of the linear accelerator at each gear dose rate is 200MU, repeatedly irradiating the clamping groove for 5 times by the linear accelerator at each gear dose rate, averaging to obtain average dose reading of each gear, and recording; the dosage rate is, for example, 200MU/min, 400MU/min, 600MU/min, 800MU/min, 1000MU/min

Comparing the average dose reading of each gear with the output dose reading of the clinical common dose rate of 1000MU/min, and judging whether the average dose reading meets the stability detection requirements at different dose rates; the clinically usual dose rate; the stability detection requirements under different dosage rates are that the average dosage reading of each grade is less than or equal to the output dosage reading of 1000MU/min of the common clinical dosage rate and is +/-2%.

fixing a beam out (MU) in a physical mode;

inserting the finger-type ionization chamber into a clamping groove II of the die body II, and measuring the tissue die body ratio TPR at the positions with the depths of 20cm and 10cm respectively; obtaining a TPR measurement value with the depth of 20cm and a TPR measurement value with the depth of 10 cm;

comparing the measured value of the TPR with the depth of 20cm with the measured value of the TPR with the depth of 10cm with a reference value of the stability of the radioactive substance, and judging whether the stability detection requirement of the radioactive substance is met;

the stability detection requirement of the radioactive substance is that the measured value is less than or equal to the stability reference value of the radioactive substance plus or minus 1 percent.

placing a quality control detection die body on a treatment bed, determining the placement position of the die body by using a front distance pointer, and inserting a finger-type ionization chamber into the clamping groove I; connecting the finger-type ionization chamber with a standard dosimeter;

Irradiating the first clamping groove by using a plurality of types of linear accelerators respectively, and acquiring the dose readings of the 3 standard dosimeters when the beam output is 200 MU;

averaging the dose readings of the 3 standard dosimeters to obtain average dose readings corresponding to the linear accelerators of a plurality of models, and recording;

performing normalization processing on a dose reading average value of a 60mm linear accelerator to obtain a plurality of normalized results, performing deviation on the normalized results and an X-ray beam flow output factor reference value to obtain deviation results corresponding to the linear accelerators of a plurality of models, and comparing the deviation results with the X-ray beam flow output factor reference value to determine whether the detection requirement of the X-ray beam flow output factor is met;

the X-ray beam current output factor detection requirement includes:

the deviation result corresponding to the 20mm linear accelerator is less than or equal to X-ray beam flow output factor reference value +/-2%;

the deviation results (excluding 20mm linear accelerator) of the linear accelerators of the multiple models are less than or equal to X-ray beam flow output factor standard value +/-1%.

In one embodiment of the invention, the evaluation of the radiation field penumbra characteristics of the linac X-ray beam based on the first, third and eighth die members specifically comprises:

Placing the bottom surface of the quality control detection die body on the ground in parallel with the ground level;

perpendicular the central axis of the radiation beam of the linac to the surface of the first body portion;

placing a no-clean film in a clamping groove II of the die body part III, and adjusting the distance from the linear accelerator to the center of the no-clean film to be 80cm by using a front-distance pointer;

a 40mm linear accelerator is selected to irradiate the second clamping groove, so that a film with an irradiation field is obtained; the irradiation dose can enable the irradiated dose of the film to be kept within the optimal linear region of the dose gray curve;

opening the corresponding image by using film analysis software, and marking the intersection points of the axes (X axis and Y axis) of the center of the irradiation field in the corresponding image and the 80% isodose curve and the 20% isodose curve respectively; measuring the distance between the two intersection points, and evaluating whether the irradiation field in the film accords with the irradiation field penumbra characteristic detection requirement of the X-ray beam of the linear accelerator based on the distance;

the radiation field penumbra characteristic detection requirement of the linac X-ray beam is as follows: the distance is less than or equal to 4mm.

placing the bottom surface of the quality control detection die body on the ground in parallel with the horizontal plane, and keeping the horizontal plane parallel;

selecting a 60mm linear accelerator, fixing the source wheelbase (SAD) of the linear accelerator to be 800mm, and irradiating the second clamping groove;

based on the beam off-axis curves in the two orthogonal directions, obtaining flatness, symmetry and penumbra of the beam by utilizing software analysis, and comparing the flatness, symmetry and penumbra of the beam with corresponding reference values respectively; the flatness, symmetry and penumbra of the beam are less than 2%, which indicates that the detection requirements are met;

in one embodiment of the invention, mechanical accuracy verification is performed based on the first die body, the seventh die body and the eighth die body;

placing the bottom surface of the quality control detection die body on the treatment bed in parallel with the horizontal plane, and mounting a film on one surface of the die body; the center of the film is aligned with the center of the surface of the first die body part;

preparing 60mm, 40mm and 10mm linear accelerators;

the beam irradiated by the linear accelerator is adjusted to be vertical to the center of the surface of the first die body piece, so that the center of the linear accelerator is aligned with the metal ball of the seventh die body piece;

respectively using 60mm, 40mm and 10mm linear accelerators to irradiate the film to obtain three film irradiation points and three corresponding metal ball points;

And respectively calculating the deviation of the three film irradiation points and the three corresponding metal ball points, wherein the deviation is less than 1mm, and meets the detection requirement.

placing the bottom surface of the quality control detection die body on a treatment bed in parallel with the horizontal plane, taking a piece of film, arranging a hole on the film to obtain the film with a film hole, inserting the film with the film hole into a clamping groove II of a die body III, adjusting the position of a laser auxiliary device, wherein the laser auxiliary device is used for assisting a linear accelerator to a transmitting position,

the position of the linear accelerator is debugged, so that the transmitting hole of the linear accelerator is aligned with the film hole, and the beam emitted by the linear accelerator is vertical to the upper surface of the quality control detection die body;

controlling a linear accelerator to start irradiation, forming irradiation points on a film with a film hole, and comparing the position deviation of the irradiation points and the film hole, wherein if the position deviation is less than or equal to 0.5mm, the position deviation indicates whether the beam laser point and the radiation field center are consistent

In one embodiment of the invention, the first die body part 1, the third die body part 3, the fourth die body part 4, the fifth die body part 5, the sixth die body part 6 and the eighth die body part 8 are subjected to software performance verification;

specifically, the software performance verification includes: CT value precision, CT image noise, CT value uniformity, CT value linearity, CT image spatial integrity,

It can be understood that the specific steps of obtaining the CT value precision, the image noise, the CT value uniformity and the CT value linearity by using the software performance verification equivalent water model are as follows:

placing the wall surface of the quality control detection die body on a treatment bed, and performing CT scanning to obtain image data, wherein the horizontal surfaces of the wall surface of the quality control detection die body are parallel;

horizontally placing the wall surface of the quality control detection die body on a treatment bed, and performing CT irradiation to obtain CT image data;

importing the image data into a TPS system to obtain a CT test image;

selecting a region of interest (ROI) with the size of about 500 pixels (about one tenth of the area of the die body) in the center of the CT test image;

selecting a contrast scale, calculating an average CT value of the region of interest (ROI) based on the contrast scale, and obtaining a standard deviation; taking the standard deviation as the CT value precision, wherein the deviation of the CT value precision is required to be + -5 HU, and if the deviation exceeds the required standard deviation, calibrating;

taking the directions of 3 points, 6 points, 9 points and 12 points in the clock as references, respectively selecting regions of interest (ROI) with the size of about 500 pixels along the position of about 10mm of the edge of a CT test image, and respectively measuring the average CT values of the four regions of interest (ROI), wherein the maximum difference value of the average CT values of the regions of interest (ROI) and the center of the image is taken as a uniformity measurement value;

four cylinders with different CT values are arranged in the die body piece six; the difference of CT values of four different cylinders is more than 100HU;

calculating the nominal CT values of various modules under the corresponding ray quality conditions according to the attenuation coefficients of various attenuation modules marked in the mold body part specification under the corresponding ray quality conditions; then calculating the difference between the nominal CT value and the average CT value of the module obtained by measurement in each CT value module, and recording the maximum difference as an evaluation parameter of CT value linearity; the detection requirement is as follows: CT value linearity is 60HU;

Testing spatial integrity based on the acquired CT test images;

using a quality control detection die body to manufacture a set of treatment plan, and generating a DRR image corresponding to the metal marker based on the metal marker in the die body piece IV;

horizontally placing the wall surface of the quality control detection die body at the isocenter of the treatment bed, and fixing the quality control detection die body;

and rotating the treatment bed around the central shaft by a plurality of angles, acquiring image data corresponding to the plurality of angles based on the image guidance system, and comparing the DRR image corresponding to the metal marker with the position deviation of the image data corresponding to the plurality of angles, wherein the position deviation is less than or equal to a position reference value +/-1 mm.

In one embodiment of the present invention, the method further comprises evaluating the center imaging positioning stability of the IGPS image based on the first, third, fifth and eighth die body pieces 1, 3, 5 and 8, and specifically comprises the steps of:

a. positioning the quality control detection die body to the isocenter position of the treatment bed according to the external laser lamp;

b. selecting a treatment plan in a treatment mode, and entering a correction stage of a treatment couch in an Alignment mode; c. the image guidance system sets proper exposure conditions (such as 60kV and 50 mA), exposes and acquires an isocenter indication point image;

d. Using a scaling tool to enlarge the image of the isocenter indication point until the metal marker can be clearly observed and placed in the center of the image, and taking an image snapshot;

e. the deviation of the isocenter indication point position from the baseline position is measured and recorded.

specifically, the image guidance verification includes: the specific steps for evaluating the tracking consistency of the target area positioning system comprise the following steps:

f. placing a quality control detection die body on a treatment bed, acquiring CT scanning images (the thickness of a scanning layer is not more than 1.25 mm), and introducing the CT scanning images into a TPS system;

g. creating a treatment plan in the TPS system and storing the treatment plan as an executable plan to generate a Digital Reconstructed Radiogram (DRR) image;

h. in QA mode, a transition is made to the treatment delivery interface through a series of user interface windows. Repositioning the phantom to bring the six degree of freedom couch bias to approximately zero;

i. using the treatment bed movement function of the treatment execution interface, translating or rotating the quality control detection die body by a plurality of different positions and recording to obtain a plurality of moving actual values;

j. using an image guidance system for exposure at each position, comparing the acquired real-time image with a digitally reconstructed radiological image (DRR) image, and recording target positioning system displacement estimated values, i.e. treatment couch corrected values at a plurality of corresponding positions displayed on a treatment execution interface;

Comparing the treatment bed correction values at the corresponding positions with the actual values of the movements, and recording deviation; deviation of the couch correction from the actual value of movement: less than or equal to + -2.0 mm.

Another embodiment of the present invention further includes, evaluating a geometric deformation degree of the kV perspective image of the IGPS, specifically including:

a. the six-degree-of-freedom robot arm is moved to a position in which the beam axis is vertically downward.

b. Fixing the quality control detection die body on a support, placing the support on a treatment bed, adjusting the support and the treatment bed to enable the quality control detection die body to be positioned at the isocenter of a linear accelerator, and aligning the quality control detection die body to an imaging plane of an IGPS imaging unit A;

c. setting kV exposure conditions by using reference imaging conditions, and collecting kV perspective images;

d. measuring the distance in the X direction and the Y direction according to scales on the image, evaluating the deviation between the measurement result and the actual result, wherein the numerical value of the deviation meets the performance requirement;

repeating the steps B-d, and measuring the geometric deformation of the IGPS imaging unit B. And detecting whether the geometric deformation meets detection requirements.

In another embodiment of the present invention, after the detecting of the plurality of items, performing system performance verification;

It can be understood that the second die body after verification is inserted into the finger-type ionization chamber and then CT scanning is carried out to obtain a CT scanning image, and the thickness of the scanning layer is not more than 1.25mm;

a. placing the quality control detection die body on a treatment bed by taking the wall surface as a horizontal plane, executing a radiotherapy plan, and measuring the actual absorbed dose by using an external standard dosimeter;

the patient specific therapy test DQA comprises the specific steps of:

creating a QA template plan based on the CT scan image;

creating a QA plan based on the QA template plan; setting executable QA plans for times;

putting a film in the die body part III, and executing the QA plan to the quality control detection die body to perform CT scanning to obtain the QA plan film;

analyzing the QA film, setting corresponding parameters and recording analysis results; the analysis results include the actual spot dose for the patient-specific treatment.

The present invention is not limited to the above-mentioned embodiments, and any changes or substitutions that can be easily understood by those skilled in the art within the technical scope of the present invention are intended to be included in the scope of the present invention.

Claims

1. A quality control detection phantom for stereotactic radiotherapy, comprising: the plurality of die body pieces are combined according to the quality control function detection requirements of the stereotactic radiotherapy, and corresponding die body pieces are selected to obtain a quality control detection die body; the die body pieces are cylinders with the same diameter; the plurality of die body parts comprise a first die body part (1), a second die body part (2), a third die body part (3), a fourth die body part (4), a fifth die body part (5), a sixth die body part (6), a seventh die body part (7) and an eighth die body part (8); when the plurality of die body pieces are used, the centers of the plurality of die body pieces are longitudinally aligned and connected according to the passing of the respective one end face of the die body pieces.

2. The quality control inspection die according to claim 1, wherein,

the die body piece is used for simulating different depths of tumors in a human body;

the second die body part comprises a first clamping groove which is used for placing the finger tip detector;

the mold body part III comprises a clamping groove II for placing a no-rinse film;

the mold body piece IV comprises a metal marking assembly and is matched with a plurality of mold body pieces for image-guided project testing;

the mold body piece five comprises a cylinder, and the mold body piece five is matched with a plurality of mold body pieces for use to evaluate the image center imaging positioning stability of the image positioning guide system IGPS;

The mold body part six comprises a cylinder assembly, and the mold body part six is matched with a plurality of mold body parts for system performance verification of stereotactic radiotherapy;

the die body piece seven comprises a spherical piece, and the die body piece seven is matched with a plurality of die body pieces for use in testing the mechanical precision of the collimator;

the die body part eight is positioned at the bottom, so that the back scattering of rays is prevented, and the measurement error caused by the back scattering of rays is avoided.

3. The quality control detection die body according to claim 2, wherein the die body member two comprises a top surface two and a peripheral wall two;

one end of the clamping groove I (21) is connected with the peripheral wall II, and the other end extends towards the inside of the die body part II; the first clamping groove comprises a clamping groove wall;

the proportional relation between the axial length of the clamping groove wall and the second diameter length of the die body part is as follows: 1:2.

4. A quality control inspection die body according to claim 3 wherein said metal marking assembly comprises: a first marker (41), a second marker (42) and a third marker (43);

the first marker (41) and the second marker (42) form a vertical interval H1 and a horizontal interval H2, and the second marker and the third marker form a vertical interval H3 and a horizontal interval H4.

5. The quality control inspection die of claim 4, wherein the ratio of the first vertical pitch to the first horizontal pitch is: 1:2; the proportional relation between the vertical interval II and the horizontal interval II is as follows: 1:2.

6. A quality control inspection die according to claim 3 wherein the cylinder is polymethylpentene, low density polystyrene, polystyrene or polyoxymethylene resin.

7. The quality control inspection die body of claim 2, wherein the cylinder assembly comprises: column one 61, column two 62, column three 63 and column four 64; the first cylinder 61, the second cylinder 62, the third cylinder 63 and the fourth cylinder 64 are symmetrically distributed around the center of the mold body six.

8. The quality control inspection die of claim 7 wherein the ratio of the heights of the first, second, third and fourth cylinders to the cylinder height of the die body part five is: 1:1:1:1:5.

9. The quality control inspection die body of claim 2 wherein the spherical member is a sphere having a diameter ratio of 1:5 to die body member seven.

10. Use of a quality control detection phantom according to any of claims 1-9 for the detection of a multi-functional item, characterized in that the detection of the multi-functional item comprises dosimetry verification quality control detection, mechanical accuracy verification, TPS system performance verification, image guided verification, evaluation of the consistency of planned and/or actual doses in the treatment planning system TPS and the performance of a patient specific treatment DQA plan.