Radiation therapy delivery

Abstract

A method for controlling a radiotherapy device, a computer-readable medium, and a radiotherapy device are disclosed. The radiotherapy device includes a radiation source coupled to a rotation device. The method includes: applying radiation to an object using the radiation source, and rotating the radiation source around the object using the rotation device according to a first fixed rotation scheme. The method also includes: during the execution of the first fixed rotation scheme, determining that the object is in a suboptimal position, suspending the radiation application of the radiation source; and recording a first rotation angle of the radiation source at the position where the radiation application is suspended.

Description

Technical Field

[0001] The present invention relates generally to the delivery of radiation therapy and, more particularly, to controlling the delivery of radiation therapy. Background Art

[0002] Radiotherapy uses ionizing radiation to treat the human or animal body. In particular, radiotherapy is often used to treat tumors in the human or animal body. In such treatment, cells that form part of the tumor are irradiated with ionizing radiation to destroy or damage these cells. However, in order to apply a prescribed dose of ionizing radiation to a target location or target area such as a tumor, the ionizing radiation will typically also pass through healthy tissue of the human or animal body. Therefore, radiotherapy has the desired result of irradiating and destroying the target area, but may also have the undesirable result of irradiating and destroying healthy tissue. In radiotherapy, it is desirable to minimize the dose received by healthy tissue.

[0003] Modern radiation therapy uses techniques to reduce the radiation dose to healthy tissue, thereby providing safe treatment. For example, a standard method to minimize the radiation dose received by healthy tissue surrounding a target area is to direct radiation to the target area from multiple different angles, such as by rotating the radiation source around the patient using a rotating gantry. In this case, the angle at which the radiation is applied is selected so that each radiation beam passes through the target area. In this way, a cumulative radiation dose can be accumulated on the target area during the treatment delivery process where the radiation source is rotated through a certain angle. However, because the radiation is applied from multiple different angles, the same, high, cumulative radiation dose is not accumulated in the healthy tissue because the specific healthy tissue that the radiation passes through varies with the angle. Therefore, the unit volume of healthy tissue receives a reduced radiation dose relative to the unit volume of the target area.

[0004] However, patient movement can affect the doses applied to different areas of the patient's body. For example, patient movement can cause movement of a tumor, so the dose applied to the target area is reduced, while the dose applied to healthy tissue is increased. In other words, if a patient moves during or before radiation therapy, this can cause a high cumulative dose to accumulate in healthy tissue areas rather than in the target area. This can reduce the effectiveness of the radiation therapy used to treat the target area and may cause damage to other healthy tissue.

[0005] There are a variety of reasons why a patient may move during or prior to radiation therapy. Large or extensive movement of a patient may include the patient shifting or sitting up. Discrete movement of a patient may include the patient coughing or sneezing. In some cases, extensive movement may correspond to discrete movement. A patient may also experience periodic physiological movement. For example, a patient's breathing may result in quasi-periodic movement of the patient, which may move the position of a target area (e.g., a tumor) relative to time.

[0006] To address this problem, known techniques include training the patient's breathing or asking the patient to hold their breath during radiation therapy. In this technique, the patient's breathing is adjusted according to the requirements of the radiation therapy. However, this may be uncomfortable or impossible for some patients and often limits the time that radiation can be applied.

[0007] In other known techniques, treatment delivery may be stopped when the patient's breathing causes the patient to move sufficiently. For example, in some existing systems, the patient's movement during inspiration or expiration may be sensed by any of a variety of known sensors, and radiation is applied only during a certain portion of the patient's breathing cycle. For example, the patient's breathing cycle may be divided into two regions: first, an optimal region where radiation should be applied, and second, a suboptimal region where radiation should not be applied for safety reasons. In response to sensing that the patient's breathing cycle has entered the suboptimal region, rotation of the gantry and application of radiation are halted, thereby stopping treatment delivery.

[0008] However, the suspension of the rotation may occur at some time after it is sensed that the patient's breathing cycle has entered the suboptimal region. This may be due to, for example, the inertia of the rotating gantry. In other words, due to the considerable mass of the gantry, the rotation may not be stopped immediately. This may mean that the rotation continues beyond a certain non-zero angle before the gantry is suspended. Therefore, after the rotation of the gantry and radiation device / radiation source is suspended, the gantry and radiation device may be at an angle greater than the angle at which the patient's breathing cycle entered the suboptimal region. Therefore, it is typically necessary to reverse the rotation of the gantry and radiation device. Such suspension and reversal of rotation may result in delays in treatment and patient throughput.

[0009] Furthermore, initiating further rotation of the gantry to apply more radiation involves accelerating the gantry back to the desired rotation speed. During this acceleration process, the amount of radiation applied at each rotation angle may not be constant and consistent, which can lead to dosimetry errors. In this way, the dose applied to the target area may be lower than desired and / or the dose applied to healthy areas may be higher than desired. In other words, the known technique results in inaccurate doses during radiation therapy.

[0010] It would be advantageous to minimize the dose received by healthy tissue during radiation therapy. It would also be advantageous to more accurately align the dose received by a target area to the expected (e.g., prescribed) dose for the target area. It would also be advantageous to increase the speed of radiation therapy and to increase patient comfort during treatment.

[0011] The present invention seeks to address these and other shortcomings encountered in the prior art by providing improved delivery of radiation therapy. Summary of the invention

[0012] The invention is set out in the claims.

[0013] According to one aspect, a method for controlling a radiotherapy device is provided. The radiotherapy device includes a radiation source coupled to a rotation device. The method includes: applying radiation to an object using the radiation source, rotating the radiation source around the object using the rotation device according to a first fixed rotation scheme. The method also includes: during the execution of the first fixed rotation scheme, determining that the object is in a suboptimal position, suspending the application of radiation by the radiation source; and recording a first rotation angle of the radiation source at the position where the application of radiation is suspended.

[0014] The method may be a computer implemented method. The suspension of radiation application may be in response to determining that the subject or patient is in a suboptimal position. Determining that the patient is in a suboptimal position may be based on patient position and / or movement information provided by a patient movement sensor.

[0015] According to one aspect, a computer-readable medium is provided, comprising computer-executable instructions which, when executed by a processor, cause the processor to perform any of the disclosed methods.

[0016] According to one aspect, a radiotherapy apparatus is provided that includes a radiation source coupled to a rotation device. The apparatus is configured to perform any of the disclosed methods. In particular, the apparatus can be configured to perform the disclosed method through a computer-readable medium, which, when executed by a processor, causes the apparatus to apply radiation to an object using the radiation source, and to rotate the radiation source around the object using the rotation device according to a first fixed rotation scheme. During execution of the first fixed rotation scheme, the apparatus determines that the object is in a suboptimal position, suspends the application of radiation by the radiation source, and records a first rotation angle of the radiation source at the position where the application of radiation is suspended. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Specific embodiments will now be described by way of example only with reference to the accompanying drawings, in which:

[0018] Figure 1a and Figure 1b A radiation therapy apparatus according to the present disclosure is described;

[0019] Figure 2 Parameters for radiation therapy according to the present disclosure are described;

[0020] Figure 3 A method of controlling a radiotherapy apparatus according to the present disclosure is described;

[0021] Figure 4 Another method of controlling a radiation therapy device according to the present disclosure is described;

[0022] Figure 5 Another method of controlling a radiation therapy device according to the present disclosure is described;

[0023] Figure 6 Another method of controlling a radiation therapy apparatus according to the present disclosure is described. DETAILED DESCRIPTION

[0024] Unlike prior art methods in which rotation of the gantry and radiation source is suspended in response to determining that the object or patient is in a suboptimal position, in the currently disclosed method, radiation application is suspended, but rotation of the radiation source continues according to a fixed rotation scheme. The angle at the position where radiation is suspended or paused is recorded. After the fixed rotation scheme and / or treatment delivery has ended, it can be determined whether the dose applied to the target area is sufficient based on the treatment plan. If the applied dose is insufficient, treatment can be continued with another fixed rotation scheme and / or treatment delivery to "fill the gap", i.e., radiation is applied to the object at an angle at a position where radiation was not applied during the first rotation scheme and / or treatment delivery. Therefore, the prescribed dose is accumulated in the target area, while the radiation dose to healthy tissue is minimized. At the same time, the speed of radiation treatment and the comfort of the patient during treatment are improved.

[0025] Below, methods, apparatus, and computer readable media for delivering radiation therapy are provided. In order to provide a clear explanation, the application of radiation therapy to a patient will be described in the most detail below. The use of the term "patient" should not be construed as limiting the application of the present disclosure. The present disclosure provides devices that can be used to apply radiation therapy to any object. The terms "subject" and "patient" are used interchangeably herein.

[0026] To provide a clear explanation, the patient's breathing will be described in the most detail below. However, the present disclosure applies to any voluntary or involuntary movement of the subject, including due to the subject's breathing or respiratory cycle, cardiac cycle, coughing, sneezing, and / or other movement.

[0027] Figure 1a and Figure 1b A radiotherapy device according to the present disclosure is described. The described arrangements should be considered to provide one or more examples of a radiotherapy device 120, and it should be understood that other arrangements are possible and can be used to perform the methods described herein. The accompanying drawings show a cross-section of a radiotherapy device 120, which includes a radiation source 100 and a detector 102 attached to a gantry 104. The gantry may include a circular support rail 106. The radiation source 100 and the detector 102 can be arranged diametrically opposite to each other. The radiation source 100 and the detector 102 can be fixed to the gantry 104 and can rotate with the gantry 104. Figure 1a and Figure 1bAlso shown is a patient 108 lying on a support surface 110. When radiation is delivered to the patient, for example according to a treatment plan, the radiation source 100 and the detector 102 can be rotated with the gantry 104 and / or around the circular support track 106 so that the radiation source 100 and the detector 102 are always arranged 180° from each other. The radiation source 100 sends radiation to the patient 108 from various angles around the patient 108 to spread the radiation dose received by healthy tissue to a larger area of ​​healthy tissue while accumulating a prescribed dose of radiation in the target area. Figure 1a In the embodiment, the radiation source 100 is located at the top of the radiotherapy device 120 and the detector 102 is located at the bottom of the radiotherapy device 120. Figure 1b Both parts are shown rotated 180°. Any rotation is possible. In some cases, the parts can be rotated another 180°, thus achieving a total rotation of 360°, with the orientation of the parts again corresponding to Figure 1a Direction in.

[0028] like Figure 1a and Figure 1b As shown, radiation may be emitted in a plane perpendicular to the axis of rotation of the radiation source 100. Thus, radiation may be delivered to a radiation isocenter 112 at the center of the gantry 104 regardless of the angle at which the radiation head is rotated about the gantry 104.

[0029] For example, according to the treatment plan, the treatment delivery may include the rotation of the radiation source 100 and the application of radiation by the radiation source 100. The treatment delivery may include a treatment arc. In the treatment delivery, the rotation of the radiation source 100 may pass through a predetermined angle. In some examples, the treatment delivery may include more than one rotation around the patient 108, for example, including a total rotation of more than 360°. The rotation of the radiation source 100 may be performed according to a fixed rotation scheme. The rotation of the radiation source 100 may include the execution, operation or implementation of a fixed rotation scheme. The fixed rotation scheme may include a predetermined rotation of the radiation source 100 that does not change during the treatment delivery. For example, the fixed rotation scheme may include continuous rotation, rotation at a constant rate, rotation at an increasing rate, rotation at a decreasing rate and / or discrete periods of rotation interspersed with periods of rest of the radiation source 100. The discrete period rotation may be a series of discrete directions relative to the patient 108. However, the fixed rotation scheme is fixed because it is not adjusted during the treatment delivery. For example, according to the treatment plan, the fixed rotation scheme may be applicable to applying a certain radiation dose to the object.

[0030] According to the prior art of suspending the application of radiation and suspending the rotation of the radiation source in response to determining that a particular patient has moved to a certain extent, a radiation therapy course / treatment for a particular patient may consist of several treatment deliveries due to the suspension or interruption caused by the patient's movement. In this case, each treatment delivery begins with the start of the rotation of the radiation source and ends when the rotation of the radiation source is suspended.

[0031] from Figure 1a and Figure 1b It can be seen that if the patient 108 remains stationary during treatment delivery, the cumulative radiation dose will accumulate at the radiation isocenter 112, as the radiation will pass through the radiation isocenter 112 throughout the rotation. The patient and the radiotherapy device 120 are arranged so that the radiation isocenter 112 coincides with the target region or target location (e.g., the location of a tumor). However, if the patient moves during treatment delivery, the radiation isocenter 112 and the target region will no longer coincide.

[0032] For discrete patient motion, such as may be caused by a cough or sneeze by the patient 108, the displacement of the radiation isocenter 112 relative to the target area may be changed by discrete amounts. For quasi-periodic patient motion, such as may be caused by the breathing of the patient 108, the displacement of the radiation isocenter 112 relative to the target area may be varied quasi-periodically. As used herein, the term "quasi-periodic" may be used to refer to motion or cycles that have a periodic variation component and that may have unpredictable or irregular components. In other words, the term may be used to refer to cycles that have a repeating pattern but may include variations in amplitude and / or period.

[0033] Different schemes for applying radiation therapy to the patient 108 are known. In intensity modulated radiation therapy (IMRT), the radiation beam is shaped to closely correspond to the distribution of unhealthy tissue. Therefore, IMRT can be described as conformal radiation therapy. The shaping of the radiation beam can be performed using a collimator (e.g., a multi-leaf collimator), whose leaves can be independently moved to provide a variety of different beam shapes. Due to the additional flexibility provided, the movement of the leaves of the multi-leaf collimator may weaken the requirement that the target area coincides with the radiation isocenter 112. In IMRT, radiation can be applied from multiple discrete beam angles. According to another scheme for applying radiation therapy, in volumetric modulated arc therapy (VMAT), radiation is applied continuously while the radiation source 100 travels through an arc trajectory. The radiation beam can be reshaped and / or changed in intensity during rotation, thereby dynamically applying a dose during the rotation of the gantry. Therefore, this scheme may be more time-saving than IMRT. The currently disclosed method is applicable to IMRT and VMAT.

[0034] Figure 2 Parameters for radiation therapy according to the present disclosure are described; these parameters are examples intended to illustrate the principles of the present disclosure and are not intended to limit the present disclosure to the described exemplary parameters.

[0035] exist Figure 2 , a curve of the interval distance as a function of time is shown. Here, the interval distance can be used to define the displacement or absolute distance between the target position within the patient 108 and the radiation isocenter 112. The time axis defines the time elapsed during a specific treatment delivery. As can be seen from the curve, the interval distance can vary quasi-periodically over time. This can correspond to the quasi-periodic movement of the patient 108. In particular, this can correspond to the quasi-periodic breathing cycle of the patient 108. For example, the peak of the curve can correspond to the time when the patient 108 inhales, and the valley of the curve can correspond to the time when the patient 108 exhales. In another example, the peak of the curve can correspond to the time when the patient 108 exhales, and the valley of the curve can correspond to the time when the patient 108 inhales. This can depend on the extent to which the patient 108 inhales when a reference position of the target position relative to the radiation isocenter 112 is obtained. The movement and / or breathing of the patient 108 can be determined based on any one or combination of suitable devices including, but not limited to, the following devices: one or more cameras, motion sensors, accelerometers, chest straps, and buttons pressed by the patient 108. In some examples, the radiotherapy device is a MR-linac (Magnetic Resonance-linac), further comprising an MR imaging device configured to track or monitor the movement of the patient or the patient's anatomical structure (i.e., the internal part of the patient). In this embodiment, determining that the patient is in a suboptimal position is based on MR data provided by the MR imaging device.

[0036] Figure 2 The horizontal dashed line on the top of the curve represents the threshold separation distance d th . Threshold separation distance d th It can represent the maximum acceptable separation distance. In other words, the threshold separation distance d th It can mean that radiation therapy is applied at and below the separation distance, and radiation therapy is not applied above the separation distance. In other words, the threshold separation distance can define the boundary between the optimal position of the patient and the suboptimal position of the patient, at which the application of radiation meets safety requirements. The threshold separation distance d th The threshold separation distance d can be determined based on the treatment plan. th The vertical dashed lines will be spaced apart by distances above the threshold spacing distance d. th The time period and the interval distance are equal to or lower than the threshold interval distance d th time periods apart.

[0037] Figure 2The middle curve of shows the rotation angle as a function of time. In this article, the rotation angle can be used to define the angle that the radiation source 100 has been rotated around the patient 108 using the rotation device. The rotation device can be described as a rotator or a rotation module. The time axis corresponds to the time axis in the interval distance curve. The rotation angle of the radiation source 100 can be varied according to a fixed rotation scheme. It can be seen from the curve that in some examples, the rotation angle of the radiation source 100 can increase continuously over time. In some examples, the rotation angle of the radiation source 100 can increase linearly over time. The movement of the radiation device around the patient 108 can be continuous or substantially continuous. Provide Figure 2 The examples shown in are for the purpose of explanation and should not be construed as limiting the present disclosure.

[0038] from Figure 2 It is understood that according to the present disclosure, the rotation of the radiation source 100 may not be suspended based on the movement of the object, for example, due to the breathing of the patient 108. In other words, according to the present disclosure, when the separation distance between the target position and the radiation isocenter 112 is greater than the threshold separation distance d th When the rotation of the radiation source 100 is not suspended, the rotation of the radiation source 100 may continue according to a fixed rotation scheme.

[0039] Figure 2 The bottom curve of shows the application of radiation as a function of time. In this article, the application of radiation can be used to define the application of a radiation dose to an object (e.g., to a patient 108) by the radiation source 100. The time axis corresponds to the time axis in the separation distance curve and the time axis in the rotation angle curve. As can be seen from the curves, the radiation source 100 can alternate between applying a non-zero radiation dose and not applying (i.e., zero) radiation dose. Although a single non-zero level of applied radiation is shown in the curves for ease of explanation, in some examples, the applied radiation may be different at different times and / or may increase or decrease over time. In some examples, the zero radiation dose may be replaced with a low / reduced radiation dose. Using the vertical dashed lines, it can be seen that one or more time periods in which the radiation source 100 applies a non-zero radiation dose may correspond to a separation distance being at or below a threshold separation distance d th The one or more time periods during which the radiation source 100 does not apply a radiation dose may correspond to a separation distance greater than a threshold separation distance d. th one or more time periods.

[0040] The radiation source 100 can be gated to apply radiation in certain time periods but not in other time periods by the radiation beam emitted by the radiation source 100. The radiation source 100 can include an electron source and a radio frequency (RF) field source. The electron source can provide a source of electrons that, for example, produces a radiation dose to be delivered to the patient 108 by striking a target. The RF field source can electromagnetically accelerate the electrons to a desired speed suitable for providing the radiation dose. The radiation source 100 can be gated by controlling the electron source to be turned on or off and / or by controlling the RF field source to be turned on or off. In this way, the application of the radiation dose by the radiation source 100 can be controlled according to desired parameters, for example, according to the above-mentioned time period and / or the above-mentioned spacing distance.

[0041] As can be seen from the above discussion, the present disclosure combines the continuous rotation of the radiation source 100 according to a fixed rotation scheme, monitoring the position and / or movement of the patient 108, and applying radiation only when the patient 108 is not in a suboptimal position. This provides the combined advantages of limiting damage to healthy tissue, accumulating cumulative radiation dose at the target location, and increasing the speed of radiotherapy. According to the present disclosure, since the radiation source 100 may not need to be suspended due to the movement of the patient 108 during treatment delivery, treatment delivery can take less time to complete. In addition, dosimetry errors caused by reversing the rotation and re-accelerating the radiation source 100 can be avoided.

[0042] Figure 3 A method 200 of controlling a radiation therapy device according to the present disclosure is described. The radiation therapy device may include Figure 1a and Figure 1b Features corresponding to the radiotherapy equipment described in and / or mentioned above.

[0043] In step 202, radiation may be applied to a subject using a radiation source 100. The radiation source 100 may be configured to provide a radiation dose to a patient 108. The radiation source 100 may be configured to provide a planned dose to the patient 108 during treatment delivery. Radiation may be applied to the patient 108 by the radiation source 100 based on the treatment plan.

[0044] In step 204, the radiation source 100 may be rotated around the object using a rotation device according to a first fixed rotation scheme. The object may include a patient 108. The radiation source 100 may be fixed to a gantry 104. The rotation of the radiation source 100 by the rotation device may be achieved by the rotation of the gantry 104. The rotation of the gantry 104 may be achieved by one or more motors or gears coupled to the gantry 104. The rotation device may include one or more motors or gears configured to cause the rotation of the gantry 104. Alternatively, the gantry 104 may be fixed and the radiation source 100 may be configured to move along the gantry 104 to achieve the rotation of the radiation source 100 around the object. In this case, the rotation device may include one or more motors or gears configured to cause the rotation of the radiation source 100. The radiation source 100 may be coupled or connected to the rotation device so that the radiation source 100 can be rotated by the rotation device. The rotation speed and / or rotation rate of the radiation source 100 may be determined and / or controlled based on the treatment plan.

[0045] In step 206, a determination may be made as to whether the object is in a suboptimal position. A suboptimal position may be a position that is not suitable for the radiation source 100 to apply radiation. A suboptimal position may be a position that is separated by a distance greater than a threshold separation distance d th The determination 206 may be performed using a variety of means. The position and / or movement of the object may be monitored, such as caused by or dependent upon voluntary and / or involuntary movement of the object. For example, the determination 206 may be made using one or more cameras viewing the patient 108. Alternatively or additionally, the determination 206 may be made using a motion sensor or accelerometer disposed on the patient 108. Alternatively or additionally, the determination 206 may be made using a strap around the patient's chest that expands during inspiration and contracts during exhalation. Alternatively or additionally, the determination 206 may be made using a mask worn by the patient 108. Alternatively or additionally, the determination 206 may be made using a button pressed by the patient 108 at some point in their breathing cycle.

[0046] Alternatively or additionally, MR data provided by an MR imaging device may be used to make the determination 206. Various other techniques may be used in addition to or in lieu of the exemplary techniques described above.

[0047] In some examples, a determination 206 may be made as to whether patient 108 is in a suboptimal position based on a signal including movement data or breathing data of patient 108. The breathing data may include at least one of an indication of inspiration by patient 108, an indication of exhalation by patient 108, an indication of an inspiration peak by patient 108, an indication of an exhalation peak by patient 108, a breathing rate of patient 108, or a breathing cycle of patient 108.

[0048] If the result of determination 206 is that the patient 108 is not in a suboptimal position, the method may return to step 202. If the result of determination 206 is that the patient 108 is in a suboptimal position, the method may continue to step 208.

[0049] In step 208, the radiation applied by the radiation source 100 may be paused. As described above, the pause in the application of radiation may be performed using gating of the radiation source 100.

[0050] In step 210, a first rotation angle of the radiation source 100 at the location where the radiation application is paused may be recorded. The first rotation angle may be recorded in a log file.

[0051] The radiation source 100 may continue to be rotated using the rotation device when the object is in a suboptimal position, when applying radiation is paused, and / or when recording the first rotation angle. In other words, since the radiation source rotates according to a fixed rotation scheme, the rotation is not interrupted or aborted in response to the object being in a suboptimal position. The rotation of the radiation source 100 using the rotation device may be controlled using a controller communicatively coupled to the rotation device. The controller may be communicatively coupled to a device for sensing the position and / or movement of the patient 108. The controller may include or be described as a computing device or processor. The controller may be any machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by the radiotherapy apparatus and its components as described herein.

[0052] The radiation source 100 can be configured to rotate continuously or substantially continuously during treatment delivery. As used herein, the term "continuously" should not be interpreted as excluding any minimal rotation interruption due to incremental rotation of the rotating device around a large number of discrete angles as part of its normal rotation mode. Instead, the term "continuously" can mean that during treatment delivery, there is no deviation from the fixed rotation scheme of the radiation source 100 through a suspension of planned rotation, a reversal of planned rotation, and / or an unplanned re-acceleration of the radiation source 100.

[0053] Although Figure 3 The methods listed in are presented in a certain order, but this should not be considered to limit the methods to the order presented. The various steps can be performed in a different order. The various steps can be performed simultaneously or substantially simultaneously. For example, the steps of applying 202 radiation using the radiation source 100 and rotating 204 the radiation source 100 can be performed simultaneously or substantially simultaneously. Alternatively or additionally, the steps of pausing 208 the application of radiation by the radiation source 100 and recording 210 the first rotation angle of the radiation source 100 can be performed simultaneously or substantially simultaneously. In this article, reference to events occurring substantially simultaneously can refer to events that overlap at least partially in time.

[0054] exist Figure 3In the illustrated method, the patient 108 may not be in a suboptimal position at the start of treatment or treatment delivery. For example, it may be determined that the patient 108 is not in a suboptimal position before starting treatment or treatment delivery.

[0055] Figure 4 Another method 300 of controlling a radiation therapy apparatus according to the present disclosure is described. Figure 4 The method described in Figure 3 The method described in, for example, is followed immediately thereafter. Figure 3 The methods described in Figure 4 The methods described in can occur during treatment delivery. In some examples, Figure 3 The method described in Figure 4 The methods described herein occur during treatment delivery, and / or Figure 4 The method described in Figure 3 For example, the patient 108 may not enter a suboptimal position throughout the treatment delivery process, or may move to a suboptimal position during the treatment delivery and remain in the suboptimal position for the remainder of the treatment delivery.

[0056] In step 302, the radiation source may continue to be rotated around the object using the rotation device according to the first fixed rotation scheme. Step 302 may be performed immediately after step 210 as described above. In step 302, the radiation source 100 may not apply radiation. In other words, in step 302, the object (e.g., patient 108) may be in a suboptimal position.

[0057] In step 304, a determination may be made as to whether the subject is in a suboptimal position. This determination may be performed using any of the means described above with respect to step 206. As described above, the term "suboptimal" should be interpreted as referring to a position of the patient 108 that is not suitable for applying radiation using the radiation source 100. In other words, a suboptimal position should be interpreted as referring to a position that is not within a threshold of an ideal position. The threshold may be determined based at least in part on the spatial distribution of the target region, the spatial distribution of healthy tissue, and / or the treatment plan.

[0058] If the result of determination 304 is that the object is in a suboptimal position, the method may return to step 302. If the result of determination 304 is that the object is not in a suboptimal position, the method may continue to step 306.

[0059] In step 306, radiation applied by radiation source 100 may be resumed. In some examples, such radiation application by radiation source 100 may be the first radiation application by the radiation source in a particular treatment delivery. In such examples, it should be understood that the term "resume" may be understood to indicate the term "start". As described above, the resumption of radiation application may be performed using gating of radiation source 100.

[0060] In step 308, a second rotation angle of the radiation source 100 at the position where the application of radiation is resumed may be recorded. The second rotation angle may be recorded in a log file. The first rotation angle and / or the second rotation angle may provide data indicating one or more time periods and / or one or more angular ranges of radiation applied to the object. Alternatively or additionally, the first rotation angle and / or the second rotation angle may provide data indicating one or more time periods and / or one or more angular ranges of radiation not applied to the object.

[0061] Although Figure 4 The methods listed in are presented in a certain order, but this should not be considered to limit the methods to the order presented. The various steps can be performed in different orders. The various steps can be performed simultaneously or substantially simultaneously. For example, the steps of resuming 306 the radiation source 100 applying radiation and recording 308 the second rotation angle of the radiation source 100 can be performed simultaneously or substantially simultaneously.

[0062] Figure 5 Another method 400 of controlling a radiation therapy apparatus according to the present disclosure is described. Figure 5 The methods described in can occur at the end of treatment delivery. For example, Figure 5 The method described in can occur in Figure 3 The methods described in and / or Figure 4 Following the method described in .

[0063] In step 402, a first dose reconstruction may be determined for a first treatment delivery. The first dose reconstruction may indicate a dose applied to an object and / or a target area in the first treatment delivery. The first dose reconstruction may be determined at least in part based on the first rotation angle and / or the second rotation angle as described above (e.g., using a log file). In other words, the first dose reconstruction may be determined based on an angular range of treatment deliveries in which radiation is applied by the radiation source 100 and / or an angular range of treatment deliveries in which radiation is not applied by the radiation source 100. The first dose reconstruction may be based at least in part on a treatment plan. For example, the first dose reconstruction may be based at least in part on the intensity of the applied radiation and / or the rotation speed or rate of the radiation source 100.

[0064] In step 404, it may be determined whether the first dose reconstruction differs from the planned dose by more than a threshold amount. The planned dose may be determined or provided by the treatment plan. The threshold amount may be determined or provided by the treatment plan. In some examples, the planned dose may correspond to a dose that a target region of the patient 108 would receive during treatment delivery if motion or suboptimal positioning of the patient 108 did not occur. In these examples, if motion or suboptimal positioning of the patient 108 occurs, it will be appreciated that the first dose reconstruction at the target region may be less than the planned dose by an amount that may or may not be greater than the threshold amount.

[0065] The reconstruction and / or determination can be performed using (online) gamma analysis or gamma index for dose reconstruction of the treatment plan. Gamma analysis combines two parameters for quality assessment: distance agreement (DTA); and dose deviation (DD). DTA can be defined as the closest distance from a point of the reference dose in the treatment plan to a point of the same dose in the dose reconstruction. DD can be defined as the percentage deviation between the dose to be applied according to the treatment plan and the dose that has been applied according to the dose reconstruction. In gamma analysis, the squares of DTA and DD can be added and the square root of this sum can be taken.

[0066] The determination of step 404 can be made for a single spatial point, and / or can be made for a one-dimensional, two-dimensional, or three-dimensional grid of spatial points corresponding to the target area of ​​the object and / or healthy tissue. In this way, an absolute comparison and / or a spatially resolved comparison can be performed. In either case, the threshold amount can include a single value or can include a one-dimensional, two-dimensional, or three-dimensional sequence or matrix of values ​​for comparison with the difference between the dose reconstruction and the planned dose at each spatial point. For example, it may be more important to achieve a dose that is closer to the planned dose at a specific spatial location within the tumor, in which case the threshold at the specific spatial location may be less than the thresholds at other spatial locations.

[0067] If the result of determination 404 is that the first dose reconstruction does not differ from the planned dose by more than a threshold amount, the process can terminate. For example, treatment of the subject or patient 108 can end for the day without further treatment delivery. If the result of determination 406 is that the first dose reconstruction does differ from the planned dose by more than a threshold amount, the process can continue to step 406.

[0068] In step 406, a second treatment delivery may be performed. The second treatment delivery may include at least rotating the radiation source 100 around the patient 108 using a rotation device, and applying radiation to the patient 108 using the radiation source 100. In other words, the second treatment delivery may be performed in a manner similar to the first treatment delivery. The second treatment delivery may include rotation according to a second fixed rotation scheme, which may be the same as or different from the first fixed rotation scheme. One or more angles may be recorded in a manner similar to that applied to the first treatment delivery. However, during the second treatment delivery, the radiation source 100 may apply radiation at or based on at least one angle at which radiation was not applied during the first treatment delivery. During the second treatment delivery, the radiation source 100 may not apply radiation at or based on at least one angle at which radiation was applied during the first treatment delivery. In this way, the second treatment delivery can be used to compensate for the incomplete application of radiation during the first treatment delivery. Parameters of the second treatment delivery may be determined based on the data in the log file. In a second treatment delivery, the radiation source 100 may be gated to not apply radiation at angles that would have applied sufficient radiation to the patient 108, as determined based on the difference between the first dose reconstruction and the planned dose and a comparison to a threshold.

[0069] For quasi-periodic motion of the patient 108, e.g., due to breathing of the patient 108, if the second treatment delivery begins at the same point in the quasi-periodic cycle as the first treatment delivery begins, and if the rotational speed used in the second treatment delivery is the same as that used in the first treatment delivery, then the target location within the subject may be spaced from the radiation isocenter 112 by a distance exceeding the threshold distance d at the same angle or angles in the second treatment delivery as occurred in the first treatment delivery. th In this case, incomplete application of the planned dose in the first treatment delivery will not be compensated. In other words, if the quasi-periodic motion of the subject is in phase with the rotation of the radiation source 100, then full application of the planned dose may not be achieved, even with many further treatment deliveries. However, if the rotation of the radiation source 100 is configured to be out of phase or anti-phase with the quasi-periodic motion of the subject, then for the first treatment delivery, there is a target location within the subject that is separated from the radiation isocenter 112 by a distance exceeding the threshold distance d th In the case of rotation angles of 100 and 100, for the second treatment delivery, these same rotation angles may not correspond to a separation distance that exceeds the threshold distance. Therefore, in the second treatment delivery, radiation source 100 may apply radiation at an angle at which radiation source 100 did not apply radiation in the first treatment delivery. In this way, the cumulative dose applied during the first treatment delivery and the second treatment delivery can be configured to correspond to a planned dose within the threshold amount.

[0070] Configuring the rotation of the radiation source 100 to be out of phase or anti-phase with the quasi-periodic motion of the subject (e.g., due to the breathing of the patient 108) can be achieved in various ways. For example, the rotation rate of the radiation source 100 during the second treatment delivery can be set based on the quasi-periodic motion of the patient 108 (e.g., the breathing rate). Alternatively or additionally, the interval between the first end time of the first treatment delivery and the second start time of the second treatment delivery can be defined based on the quasi-periodic motion of the patient 108 (e.g., the breathing rate). In some examples, a signal indicating a certain point in the quasi-periodic motion cycle of the patient 108 can trigger the start of the second treatment delivery at the second start time.

[0071] A second dose reconstruction may be determined for the second treatment delivery in step 408. The second dose reconstruction may be determined in a manner similar to the first dose reconstruction, except that the second dose reconstruction is determined based on data (eg, one or more angles) corresponding to the second treatment delivery.

[0072] In step 410, it is determined whether the sum of the first dose reconstruction and the second dose reconstruction differs from the planned dose by more than a threshold amount. In other words, it is determined whether the second treatment delivery adequately compensates for the incomplete application of the planned dose during the first treatment delivery. As described above, the determination and definition of the threshold amount can be made in an absolute manner or in a spatially resolved manner.

[0073] If the result of determining 410 is that the sum of the first dose reconstruction and the second dose reconstruction does not differ from the planned dose by more than a threshold amount, the process can terminate. For example, treatment of the patient 108 can end for the day without further treatment delivery. If the result of determining 410 is that the sum of the first dose reconstruction and the second dose reconstruction does differ from the planned dose by more than a threshold amount, the process can continue to step 412.

[0074] It can be expected that the above steps will be sufficient to achieve a total applied dose close to the planned dose, where the deviation of the first dose reconstruction from the planned dose is due to the quasi-periodic motion of the object, due to the consideration of the quasi-periodic motion of the object and the phase of the rotation of the radiation source 100. However, in particular in the event of further motion of the object, for example, due to a cough or sneeze of the patient 108, one or more further treatment deliveries may be performed.

[0075] In step 412, a third treatment delivery may be performed. The third treatment delivery may be performed in a manner similar to the second treatment delivery. However, during the third treatment delivery, radiation source 100 may apply radiation at or based on at least one angle where radiation was not applied during the first treatment delivery or the second treatment delivery. During the third treatment delivery, radiation source 100 may not apply radiation at or based on at least one angle where radiation was applied during the first treatment delivery or the second treatment delivery. In this way, the third treatment delivery may be used to compensate for the incomplete application of radiation during the first treatment delivery and the second treatment delivery.

[0076] It should be appreciated that further dose reconstructions, determinations, and treatment deliveries can be performed in a similar manner as described above, for example, until the sum of the dose reconstructions differs from the planned dose by less than a threshold amount. In some examples, the number of treatment deliveries performed can be limited based on a cumulative dose applied to healthy tissue, for example, to ensure the safety of the patient 108, or based on a time limit.

[0077] In some examples, adaptive radiation therapy (ART) can be used to change the planned dose and / or treatment plan during or between treatment deliveries. Such changes can be based on real-time measurements of the patient's anatomical structure during treatment delivery (e.g., using MR imaging) and / or based on post-treatment measurements. This can be used to illustrate changes in the patient 108 (e.g., target area) during radiation therapy for the patient / target area when the initial treatment plan is formulated. It can also be used to take into account uncertainties in the patient 108 setting or the radiation therapy device 120 setting. In these examples, references to the planned dose in the context of the methods described herein can be considered as references to the updated planned dose. The updated planned dose can be based on the above-mentioned planned dose and measurement. The planned dose can be updated continuously or at intervals or at predefined points. For example, it can be determined whether the first dose reconstruction differs from the updated planned dose by more than a threshold amount, whether the sum of the first dose reconstruction and the second dose reconstruction differs from the updated planned dose by more than a threshold amount, and / or whether the sum of the further dose reconstruction differs from the updated planned dose by more than a threshold amount.

[0078] Figure 6 Another method 500 of controlling a radiation therapy apparatus according to the present disclosure is described.

[0079] In step 502, the rate of motion of the object may be determined. The motion may be quasi-periodic motion, such as due to the breathing of the patient 108. The determination may be made based on any one or combination of suitable devices including, but not limited to, one or more cameras, motion sensors, accelerometers, chest straps, buttons pressed by the patient 108, and MR imaging equipment. More than one of these devices may be used in combination. Such merging of multiple data streams may improve accuracy and / or robustness. For example, the rate of motion may be recorded in a log file.

[0080] In step 504, the radiotherapy device may be configured to perform a first treatment delivery and a second treatment delivery based on the rate of motion of the object. The first treatment delivery may include a first fixed rotation scheme. The second treatment delivery may include a second fixed rotation scheme. For example, the radiotherapy device may be configured so that the cumulative dose applied during the first treatment delivery and the second treatment delivery corresponds to a planned dose within a threshold amount. For example, the rotation or rotation rate of the radiation source in the first treatment delivery and / or the second treatment delivery may be controlled to be out of phase with the motion of the object, such as inverse phase. Alternatively or additionally, the time interval between the first end time of the first treatment delivery and the second start time of the second treatment delivery may be configured so that the start of the second treatment delivery corresponds to a second point in the motion cycle of the object, and the second point is different from the first point in the motion cycle corresponding to the start of the first treatment delivery. In other words, the second point may be different from the first point because it occurs at a different stage in the motion cycle of the object. For example, the first point and the second point may be separated by a non-integer number of wavelengths of the motion cycle of the object. In this way, the second treatment delivery can be started at a time so that the second treatment delivery can compensate for the incomplete application of the planned dose during the first treatment delivery.

[0081] In step 506 , a first therapy delivery is performed as configured in step 504 .

[0082] In step 508 , a second therapy delivery is performed as configured in step 504 .

[0083] The methods described herein may be embodied on a computer-readable medium, which may be a non-transitory computer-readable medium. The computer-readable medium may carry computer-readable instructions arranged to be executed on a processor to cause the processor to perform any or all of the methods described herein.

[0084] The term "computer-readable medium" as used herein refers to any medium that stores data and / or instructions for causing a processor to operate in a particular manner. Such storage media may include non-volatile media and / or volatile media. Non-volatile media may include, for example, optical disks or magnetic disks. Volatile media may include dynamic memory. Exemplary forms of storage media include: floppy disks, flexible disks, hard disks, solid-state drives, magnetic tapes or any other magnetic data storage media, CD-ROMs, any other optical data storage media, any physical media with one or more hole patterns, RAM, PROMs, EPROMs, FLASH-EPROMs, NVRAMs, and any other memory chips or cassettes.

[0085] It should be understood that the above description is intended to be illustrative rather than limiting. After reading and understanding the above description, many other embodiments will be apparent to those skilled in the art. Although the present disclosure has been described with reference to specific example embodiments, it will be appreciated that the present disclosure is not limited to the described embodiments, but can be implemented with modifications and changes within the scope of the appended claims. Therefore, the description and drawings should be considered illustrative rather than restrictive. Therefore, the scope of the present disclosure should be determined with reference to the appended claims and the full scope of equivalents to which these claims are entitled.

Claims

1. A radiotherapy device (120), comprising: a radiation source (100) configured to apply radiation to a subject (108); a rotation device configured to rotate the radiation source (100) around the object (108) according to a first fixed rotation scheme; means for sensing the position and / or movement of the object (108); as well as a controller communicatively coupled to the rotating device and to the means for sensing the position and / or movement of the object (108), the controller being configured to: During execution of the first fixed rotation scheme: using the means for sensing position and / or movement of the object (108), determining that the object (108) is in a suboptimal position in which a separation distance between a target location within the object (108) and a radiation isocenter (112) is greater than a threshold separation distance; In response to determining that the object (108) is in the suboptimal position, pausing application of radiation by the radiation source (100); and recording a first rotation angle of the radiation source (100) at a position where application of radiation is paused, The controller is configured to set at least one of a rotation speed of the radiation source (100) and a start time for the radiation source (100) to start rotating based on a signal including movement data of the object (108) and / or a signal including breathing data of the object (108).

2. The radiotherapy device (120) according to claim 1, characterized in that The controller is configured to, during execution of the first fixed rotation scheme: determining that the object (108) is not in a suboptimal position; resuming application of radiation from the radiation source (100); as well as A second rotation angle of the radiation source (100) at the location where the recovery radiation is applied is recorded.

3. The radiotherapy device (120) according to claim 1 or 2, characterized in that: The first treatment delivery includes: rotating the radiation source (100) around the object (108) using the rotation device according to the first fixed rotation scheme, and applying radiation to the object (108) using the radiation source (100), wherein the controller is configured to determine a first dose reconstruction for the first treatment delivery based at least in part on the first rotation angle at a first end time when the first treatment delivery has been completed.

4. The radiation therapy apparatus (120) of claim 3, wherein the controller is configured to determine whether the first dose reconstruction differs from a planned dose by more than a threshold amount.

5. The radiotherapy device (120) according to claim 4, characterized in that The controller is configured to update the planned dose based on one or more measurements taken during and / or after the first treatment delivery, wherein the controller is configured to determine whether the first dose reconstruction differs from the planned dose by more than the threshold amount, including: being configured to determine whether the first dose reconstruction differs from the updated planned dose by more than the threshold amount.

6. The radiotherapy apparatus (120) of claim 4 or 5, the radiotherapy apparatus being configured to: in response to a determination by the controller that the first dose reconstruction differs from the planned dose by more than the threshold amount, perform a second treatment delivery, the second treatment delivery comprising: applying radiation to the object (108) using the radiation source (100); as well as According to a second fixed rotation scheme, the radiation source (100) is rotated around the object (108) using the rotation device.

7. The radiotherapy device (120) according to claim 6, characterized in that The radiotherapy device (120) is configured to apply radiation to the patient using the radiation source (100) during the second treatment delivery period, including: The radiotherapy device (120) is configured to apply radiation at or based on the first rotation angle.

8. The radiotherapy device (120) according to claim 6, characterized in that The controller is configured to determine a second dose reconstruction for the second treatment delivery at a second end time when the second treatment delivery has been completed. Optionally, the controller is configured to determine whether the sum of the first dose reconstruction and the second dose reconstruction differs from the planned dose by more than the threshold amount.

9. The radiotherapy apparatus (120) according to claim 1 or 2, wherein the radiotherapy apparatus is configured to execute a treatment plan, wherein the treatment plan comprises: a first treatment delivery comprising: rotating the radiation source (100) around the object (108) using the rotation device according to the first fixed rotation scheme, and applying radiation to the object (108) using the radiation source (100); and A second treatment delivery includes: rotating the radiation source (100) around the object (108) using the rotation device according to a second fixed rotation scheme, and applying radiation to the object (108) using the radiation source (100).

10. The radiotherapy device (120) according to claim 9, characterized in that The treatment plan includes: a first rotation rate of the radiation source (100) during the first treatment delivery, the radiotherapy device (120) being configured to determine the first rotation rate based on a signal including movement data of the object (108); and / or a second rotation rate of the radiation source (100) during the second treatment delivery, the radiotherapy device (120) being configured to determine the second rotation rate based on a signal including movement data of the object (108); and / or the treatment plan includes a time interval between a first end time of the first treatment delivery and a second start time of the second treatment delivery, the radiotherapy device (120) being configured to determine the time interval based on a signal including movement data of the object (108).

11. The radiotherapy device (120) according to claim 9, characterized in that: The controller is configured to control the rotation of the radiation source (100) to be out of phase with the movement of the object (108). Optionally, the controller is configured to control the rotation of the radiation source (100) to be in anti-phase with the movement of the object (108).

12. The radiotherapy device (120) according to claim 1, characterized in that The controller being configured to determine that the object (108) is in a suboptimal position includes the controller being configured to determine that the object (108) is in a suboptimal position based on a signal including movement data of the object (108) and / or based on a signal including breathing data of the object (108).

13. The radiotherapy device (120) according to claim 1, characterized in that The radiation source (100) is configured to rotate substantially continuously during the first fixed rotation scheme.

14. The radiotherapy device (120) according to claim 1, characterized in that The controller is configured to record the first rotation angle of the radiation source (100) comprises: the controller is configured to record the first rotation angle of the radiation source (100) in a log file.

15. A computer readable medium comprising computer executable instructions which, when executed by a processor, cause a radiation therapy device (120): applying radiation to a subject (108) using a radiation source (100); According to a first fixed rotation scheme, the radiation source (100) is rotated around the object (108) using a rotation device; and During execution of the first fixed rotation scheme: Using a device for sensing position and / or movement of the object (108), determining that the object (108) is in a suboptimal position in which a separation distance between a target location within the object (108) and a radiation isocenter (112) is greater than a threshold separation distance; In response to determining that the object (108) is in the suboptimal position, pausing application of radiation by the radiation source (100); and recording a first rotation angle of the radiation source (100) at a position where application of radiation is paused, in, At least one of a rotation speed of the radiation source (100) and a start time for the radiation source (100) to start rotating is set based on a signal including movement data of the object (108) and / or a signal including breathing data of the object (108).

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