Methods for accurately locating the target area of ​​radiotherapy lesions

Abstract

The present invention discloses a method for accurately locating a target area of ​​a radiotherapy lesion, aiming to provide a positioning method with high positioning efficiency and the ability to reduce positioning systematic errors. The present invention is implemented by the following technical scheme: a positioning ball sticker fixed to a phantom or a human body for locating a tumor is formulated, a fluorescent or phosphorescent cross scale cross line is printed on the positioning ball sticker, and a metal ball is fixed at the center of the intersection; a body surface positioning sticker fixed to the human body with a cross scale scale line as the phantom installation positioning during radiotherapy; after the phantom is initially installed in place, the horizontal scale line of the surface positioning sticker is aligned with the edge of the phantom and fixed to the body surface for phantom positioning; in a dark room, the cross scale cross line of the luminous positioning ball sticker coincides with the laser cross line of the positioning system, and the positioning ball sticker is fixed on the phantom; the positioning ball sticker is developed under an X-ray machine to obtain the location of the patient's tumor; and precise radiotherapy is performed accordingly. The present invention effectively reduces the systematic error of precise tumor positioning during radiotherapy.

Description

Technical Field

[0001] The present invention relates to a medical X-ray accessory device and component-X-ray fluoroscopy, photography, and a method for accurately locating a radiotherapy lesion target area. Background Art

[0002] Radiotherapy is an important method of tumor treatment. According to statistics, more than 70% of malignant tumor patients need to receive radiotherapy at different stages of their treatment. The advantage of radiotherapy is that it can treat a wide range of diseases, is not limited by anatomical structures, and has good efficacy. Radiotherapy generally goes through the stages of CT scanning, radiotherapy planning, simulation positioning, positioning, and radiotherapy implementation.

[0003] With the development of electronic technology, current radiotherapy equipment has made breakthrough progress in radiotherapy accuracy and three-dimensional conformality. The most representative precision radiotherapy technologies developed on the basis of traditional three-dimensional conformal radiotherapy and intensity-modulated radiotherapy include conformal radiotherapy (ART), image-guided intensity-modulated radiotherapy (IGRT), spiral tomotherapy (Tomotherapy), proton radiotherapy, stereotactic body radiotherapy (SBRT), volumetric arc modulated technology (VMAT), Cyberknife technology, etc. Among them, image-guided intensity-modulated radiotherapy can integrate the positioning of patients or tumors, image-guided tools of treatment machines and other mobile systems, and more accurately guide the radiation beam to the tumor target area in the patient's body. Since the boundary of the planned target volume (PTV) including the clinical target volume (CTV) must take into account the uncertainty of the positioning and the movement of organs, the uncertainty caused by the positioning error and the movement of organs becomes larger. In clinical practice, the clinical target volume is usually expanded by a certain boundary to form an inner target volume and a planned target volume, so as to include the tumor invasion range caused by organ movement and positioning, so as to avoid missing the target area, but this also increases the radiation dose of the surrounding normal tissues and organs at risk, and increases the incidence of secondary tumors. Traditional radiotherapy has large errors caused by positioning and organ movement, low tumor control rate and treatment gain ratio, long treatment time, and low treatment efficiency. In order to reduce the impact of positioning errors, respiratory movement and other errors on radiotherapy, it is usually adopted in clinical practice to expand the clinical target volume (CTV) by a certain area boundary to form a planned target volume (PTV), but this will inevitably increase the radiation dose of the surrounding normal tissues and organs. Once the target area dose deviation reaches 3%-5%, it may cause a decrease in the effectiveness of radiotherapy of the primary tumor and an increase in the probability of radiological complications of the surrounding normal tissues. It can be seen that a series of uncertainties in radiotherapy, such as positioning error, organ motion, and planning optimization algorithm error, have significant significance for the accuracy of radiotherapy. The use of thermoplastic phantoms can effectively reduce organ motion, so the precise installation and precise positioning of the phantom can effectively improve the accuracy of radiotherapy.

[0004] The current method of positioning tumors in clinical radiotherapy is as follows: after formulating a radiotherapy plan, the first step is to make a phantom covering the radiotherapy area for the patient who needs radiotherapy to ensure the consistency of the patient's body during multiple radiotherapy operations. After the phantom is installed, use a marker pen to draw lines on the patient's body along the outline of the phantom as an indication of the position for reinstallation; then place the lead point at the intersection of the laser crosshairs of the laser positioning system for radiotherapy in a dark room, fix the lead point with a sticker, and draw the laser crosshairs on the sticker as the coordinate point for tumor positioning; then perform multi-angle imaging or CT scanning under an X-ray machine. The doctor obtains the relative position of the tumor and the lead point based on the image data, that is, the position of the patient's tumor CT positioning. Since the lead point is located at the intersection of the laser crosshairs of the laser positioning system, the CT positioning position of the tumor coincides with the position of the radiotherapy target area. During this series of operations, the lines of the marker pen are thicker, and the marking lines drawn on the patient's body surface are easily diffused and blurred by sweat, bathing, and friction from clothes, and they will fade and fall off. In multiple treatments, the installation accuracy of the phantom is large. In addition, in the operation of aligning the intersection of the laser crosshairs of the laser positioning system, the lead point is not obvious in the dark room and is difficult to place accurately. The placement site is uneven and prone to deviation. In addition, the phantom is uneven, the accuracy of manual tracing is poor, and the operation is time-consuming. In the traditional tumor radiotherapy positioning process, the accumulated errors of all steps can sometimes be as high as 1 cm, resulting in the frequent occurrence of mismatches between the patient's simulator positioning and treatment positioning, and mismatches between the planned irradiation field and the actual irradiation field in actual operations. Summary of the invention

[0005] The purpose of the present invention is to address the problem of low positioning accuracy in tumor radiotherapy during existing precision radiotherapy, and to provide a method for accurately positioning the target area of ​​radiotherapy lesions, which can improve the accuracy of the target area and the precision of radiotherapy, wherein the marking line is not affected by external factors, has high positioning efficiency, and can reduce the systematic error of positioning.

[0006] The technical solution adopted by the present invention to solve its technical problem is a method for accurately locating a target area of ​​a radiotherapy lesion, which is characterized by comprising the following steps: preparing a positioning ball sticker 1 fixed to a phantom or a human body as a tumor positioning during radiotherapy, making a scale identification line engraved by using fluorescence or phosphorescence technology on the positioning ball sticker 1, the scale identification line is a fluorescent or phosphorescent cross scale cross line 2, and fixing a metal ball 3 at the center of the intersection of the fluorescent or phosphorescent cross scale cross line 2 as the identification line ruler; fixing a body surface positioning sticker 5 fixed to the human body as a phantom installation positioning during radiotherapy, and making a cross scale scale line 6 on the body surface positioning sticker 5; after the patient phantom is initially installed in place, inserting the self-adhesive body surface positioning sticker 5 with the cross scale scale line 6 between the phantom and the patient's body surface, adjusting The body surface positioning sticker 5 is positioned, and the horizontal scale line of the body surface positioning sticker 5 is aligned with the edge of the phantom, and then fixed on the patient's body surface as the coordinate point for positioning the phantom; in a dark room, the positioning ball sticker 1 is adjusted to make the luminous cross scale intersection line 2 coincide with the laser cross intersection line of the positioning system, and the metal ball 3 is set at the laser cross intersection point, and the positioning ball sticker 1 is fixed on the phantom; multi-angle development or CT scanning is performed under an X-ray machine, and the relative position of the tumor and the metal ball 3 on the positioning ball sticker 1 is obtained according to the obtained image data, and the simulated positioning of the patient's tumor is obtained; according to the simulated positioning information of the tumor, the operating steps of the simulated positioning are repeated, and the positioning ball stickers 1 with different fluorescent colors are fixed on the phantom as positioning ball stickers for positioning, and used for the radiotherapy device to guide the irradiation field delineation and the implementation of the radiotherapy plan.

[0007] Compared with the prior art, the present invention has the following beneficial effects:

[0008] Improve the accuracy of the target area and the precision of radiotherapy. The present invention uses a positioning ball sticker 1 with a metal ball 3 that can be developed under X-rays and a cross-scale fluorescent marking line ruler that can emit light in a dark room to guide the positioning of a laser positioning system. The three-dimensional position of the tumor is calibrated under X-rays and used for radiotherapy devices to guide the delineation of irradiation fields and the implementation of radiotherapy plans; the body surface positioning sticker 5 is fixed to the human body and used as a body model for installation and positioning during radiotherapy. The body surface positioning sticker 5 is provided with a cross-scale scale line 6; the accuracy of target area motion control has been greatly improved, and the tumor control rate and treatment gain ratio have also been significantly improved. In addition, great progress has been made in treatment time and efficiency, which greatly shortens the treatment time and improves the treatment efficiency, thereby reducing the uncertainty caused by time and improving the local control rate of tumors.

[0009] The marking line is not affected by external factors. The present invention uses a waterproof and breathable PU film with a ruler line as a body surface positioning sticker 5 to replace the marking pen, and is not affected by the patient's sweating, bathing, and clothing friction. This body surface positioning sticker 5 with a cross ruler scale line 6 is used to guide the installation of the phantom. The scale can display the deviation of the phantom after installation (the patient's body shape usually changes during multiple treatments, which inevitably leads to deviations when the phantom is installed). The deviation can be corrected by setting the irradiation field of the current radiotherapy plan accordingly. The problem that the existing technology uses thicker pen lines to guide radiotherapy operations has large errors, and the marking lines are easily diffused and blurred due to sweating, bathing, and clothing friction, and will fade and drop. It can avoid damage to normal tissues and organs when giving radiotherapy to patients, reducing the difficulty of medical staff's work.

[0010] High positioning efficiency. The present invention has scale marking lines engraved with fluorescent or phosphorescent technology on the positioning ball sticker 1, and the metal ball 3 is fixed at the center of the cross axis intersection. The marking lines are clear and conspicuous in the dark room. It is only necessary to match the cross scale ruler with the laser cross line of the positioning system and then fix it. The scale ruler can display the operation deviation, and the irradiation field can be adjusted for correction when formulating the radiotherapy plan to ensure the accurate implementation of the radiotherapy plan, thereby further improving the positioning efficiency. Moreover, the cross scale scale lines 6 made on the body surface positioning sticker 5 can indicate the operation deviations up, down, left and right during installation, and can be corrected by setting the corresponding movement of the irradiation field of the current radiotherapy plan, thereby improving the clinical operation efficiency and ensuring the positioning accuracy of radiotherapy.

[0011] It can reduce the systematic error of positioning. The present invention uses a waterproof and breathable PU film with a ruler line as a body surface positioning sticker 5 to replace the marking pen. The thickness of the marking line is only 1 / 5 of the thickness of the marking pen, which effectively reduces the systematic installation error caused by multiple installations of the phantom; the radiotherapy positioning ball uses a cross ruler line of fluorescence (phosphorescence) technology located at the center of the cross intersection to digitize the installation deviation, and combines CT positioning with laser positioning by using a fluorescent scale ruler to accurately locate the target area of ​​the lesion. In the dark room, it can conveniently guide the precise positioning of the laser positioning auxiliary system, improve the positioning efficiency and accuracy, and effectively reduce the systematic error of precise positioning of the tumor during radiotherapy. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a front view of the method for accurately locating the target area of ​​a radiotherapy lesion according to the present invention.

[0013] Figure 2 yes Figure 1 Top view of the .

[0014] Figure 3 It is cooperation Figure 1 5 front view of the body surface positioning sticker.

[0015] In the figure: 1 positioning ball sticker, 2 fluorescent or phosphorescent cross scale cross lines, 3 metal ball 3, 4 dry glue separation sticker, 5 body surface positioning sticker, 6 cross scale scale lines. DETAILED DESCRIPTION

[0016] See also Figure 1 . According to the present invention, a positioning ball sticker 1 is formulated and fixed on a phantom or a human body for positioning a tumor during radiotherapy. Scale marking lines engraved using fluorescent or phosphorescent technology are made on the positioning ball sticker 1. The scale marking lines are fluorescent or phosphorescent cross scale cross lines 2. A metal ball 3 is fixed at the center of the intersection of the fluorescent or phosphorescent cross scale cross lines 2 serving as the marking line scale. The fluorescent or phosphorescent cross scale cross lines 2 are used for imaging and positioning under X-rays. The fluorescent or phosphorescent cross scale cross lines 2 are cross scale fluorescent marking line scales used to display deviation conditions and guide the positioning of the laser positioning system. As the radiotherapy positioning ball sticker 1, a self-adhesive sticker having fluorescent or phosphorescent cross scale cross lines 2 thereon is used, and the self-adhesive sticker is provided with a dry adhesive separation sticker 4.

[0017] The positioning ball sticker 1 is divided into a CT positioning ball sticker and a positioning ball for positioning the positioning ball. The difference between the CT positioning ball sticker and the positioning ball sticker for positioning the positioning ball is that the color of the cross-scale fluorescence or phosphorescence is different. The CT positioning ball sticker is green if the fluorescent or phosphorescent cross-scale cross-line 2 is green; the positioning ball sticker is blue if the fluorescent or phosphorescent cross-scale cross-line 2 is blue. Because the radiotherapy patient needs to undergo CT examination for tumor positioning and pre-treatment tumor positioning during treatment, the positioning ball sticker 1 is distinguished by using cross-scale fluorescent rulers of different colors. The CT positioning ball sticker and the positioning ball sticker for positioning the positioning ball are used to locate the tumor during CT scanning and positioning, respectively. The cross-scale fluorescent marking line ruler can emit light in a dark room, and is used to guide the doctor to match the laser cross-line of the laser positioning system for radiotherapy in the dark room and then fix it on the phantom or human body. The metal ball 3 in the center of the cross-line of the positioning ball sticker 1 is developed under X-ray, and the precise position of the tumor can be determined by CT scanning. When the cross-line of the positioning ball sticker 1 matches the laser cross-line of the laser positioning system, the actual position of the tumor is consistent with the target area position of the radiotherapy plan. Taking into account possible deviations during actual operation, the scale of the cross-scale fluorescent marker line ruler can be used to obtain the positioning ball, pointing to the deviation value of the center point of the two cross-lines of the positioning ball. This deviation value can be calibrated by adjusting the radiotherapy plan.

[0018] A phantom that is consistent with the patient's body and covers the radiotherapy area is prepared, and a positioning ball sticker 1 with a metal ball 3 that can be developed under X-ray is combined with a cross-scale fluorescent marking line ruler that guides the positioning of the laser positioning system. The three-dimensional position of the tumor is calibrated under X-ray development, and is used by the radiotherapy device to guide the delineation of the irradiation field and the implementation of the radiotherapy plan; after the patient phantom is initially installed in place, a self-adhesive body surface positioning sticker 5 with a cross-scale scale line 6 is inserted between the phantom and the patient's body surface, the position of the body surface positioning sticker 5 is adjusted, and the horizontal scale line of the body surface positioning sticker 5 is aligned with the edge of the phantom, and then fixed on the patient's body surface as a coordinate point for tumor positioning; multi-angle development or CT scanning is performed under an X-ray machine, and the relative position of the tumor and the metal ball 3 fixed at the center of the intersection of the fluorescent or phosphorescent cross scale cross line 2 on the positioning ball sticker 1 is obtained according to the image data, and the position of the patient's tumor CT positioning is obtained.

[0019] See also Figure 3 The body surface positioning sticker 5 is a medical PU film with a cross scale mark 6, the PU film is waterproof and breathable, and the cross scale mark 6 is used to guide the installation of the phantom and display the deviation status.

[0020] After the patient's phantom is installed in place for the first time, insert the body surface positioning sticker 5 between the phantom and the body surface, adjust the position of the body surface positioning sticker 5 so that the scale line (horizontal line) is aligned with the edge of the phantom, peel off the dry adhesive separation sticker 4, and fix the body surface positioning sticker 5 to the patient's body surface to mark the installation position of the phantom and guide the re-installation of the phantom. During the first installation, if the scale line is not aligned with the edge of the phantom due to operational reasons, the interval distance can be marked on the phantom at that location, and the same distance can be maintained when re-installed. If the target area is not aligned during the first installation, it can be moved accordingly.

[0021] After the phantom is installed and marked, the patient is sent to a dark room. Under the guidance of the laser crosshairs of the laser positioning system, the fluorescent crosshairs of the CT positioning ball sticker and the positioning ball sticker are aligned with the laser crosshairs during CT positioning and positioning, and then the release paper is removed and the positioning ball sticker 1 is fixed on the phantom. If it is not aligned due to operational reasons, the interval distance can be marked on the phantom at that location, and the target area can be moved accordingly.

Claims

1. A method for accurately locating a radiotherapy lesion target area, characterized in that The method comprises the following steps: preparing a positioning ball sticker (1) fixed on a phantom or a human body for positioning a tumor during radiotherapy, wherein the positioning ball sticker (1) is provided with scale marking lines using fluorescent or phosphorescent technology, wherein the scale marking lines are fluorescent or phosphorescent cross scale lines (2), and a metal ball (3) is fixed at the center of the intersection of the fluorescent or phosphorescent cross scale lines (2) as marking line scales; fixing a body surface positioning sticker (5) fixed on a human body for positioning a phantom during radiotherapy, wherein the body surface positioning sticker (5) is provided with cross scale lines (6); after the patient phantom is initially installed, inserting the self-adhesive body surface positioning sticker (5) provided with the cross scale lines (6) between the phantom and the patient's body surface, adjusting the position of the body surface positioning sticker (5), and adjusting the position of the body surface positioning sticker (5). The horizontal scale line is aligned with the edge of the phantom and then fixed on the patient's body surface as a coordinate point for positioning the phantom; in a dark room, the positioning ball sticker (1) is adjusted so that the luminous cross scale intersection line (2) coincides with the laser cross intersection line of the positioning system, the metal ball (3) is set at the laser cross intersection point, and the positioning ball sticker (1) is fixed on the phantom; multi-angle imaging or CT scanning is performed under an X-ray machine, and the relative position of the tumor and the metal ball (3) on the positioning ball sticker (1) is obtained based on the obtained image data, so as to obtain the simulated positioning of the patient's tumor; according to the simulated positioning information of the tumor, the operation steps of the simulated positioning are repeated, and the positioning ball sticker (1) with different fluorescent colors is fixed on the phantom as a positioning ball sticker for use in the radiotherapy device to guide the delineation of the irradiation field and the implementation of the radiotherapy plan.

2. The method for accurately locating a target area for a radiotherapy lesion according to claim 1, characterized in that: As the radiotherapy positioning ball sticker (1), a self-adhesive sticker having fluorescent or phosphorescent cross scale cross lines (2) formed thereon is used, and the self-adhesive sticker is provided with a dry adhesive separation sticker (4).

3. The method for accurately locating a target area for a radiotherapy lesion according to claim 2, characterized in that: The positioning ball sticker (1) combines a metal ball (3) with a cross-scale fluorescent marking line scale for guiding the positioning of a laser positioning system, and calibrates the three-dimensional position of a tumor under X-ray development, and is used in a radiotherapy device to guide the delineation of an irradiation field and the implementation of a radiotherapy plan.

4. The method for accurately locating a target area for a radiotherapy lesion according to claim 3, characterized in that: The positioning ball stickers (1) are divided into CT positioning ball stickers and positioning positioning balls. The difference between the CT positioning ball stickers and the positioning ball stickers is the different colors of the cross-degree line fluorescence or phosphorescence.

5. The method for accurately locating a target area for a radiotherapy lesion according to claim 4, characterized in that: If the cross-line (2) of the fluorescent or phosphorescent cross scale is green, it is a CT positioning ball sticker; if the cross-line (2) of the fluorescent or phosphorescent cross scale is blue, it is a positioning positioning ball sticker.

6. The method for accurately locating a target area for radiotherapy lesions according to claim 1, characterized in that: CT positioning ball stickers and positioning ball stickers are used to locate tumors during CT scanning and positioning respectively.

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