Warming Assembly

Abstract

An assembly (1) for a hyperthermia treatment of a target region of biological tissue, comprising: a thermal energy generator (3); an energy applicator (2) coupled to the generator and configured for applying thermal energy to the target region so as to induce a temperature change; an MRI image acquisition device (4) configured for generating at least one MRI anatomical image (IMG_IRM_A) and at least one phase image (IMG_IRM_P); and a planning unit (5) comprising MRI image processing means (6) configured for defining a target region Rc, a region to be preserved Rp and a neutral region R on the at least one MRI anatomical image (IMG_IRM_A), wherein the MRI image processing means also calculates a hyperthermia treatment time for each of the three regions. an MRI image acquisition device (4) for receiving data originating from the planning unit (5) and from the MRI image acquisition device (4) in real time during the heating treatment phase, the monitoring unit (9) comprising means (10) for generating a temperature image from at least one phase image (IMG_IRM_P), means (11) for calculating a reliability indicator from the temperature variations shown on the temperature image, and means (12) for calculating an indicator of the state of the heating treatment in each of the three regions.

Description

[Technical field]

[0001] The present invention provides a method for the localization of temperature under intraoperative imaging guidance. change The present invention relates to the field of treating biological tissue by

[0002] More specifically, the present invention relates to an assembly and a method that allows the real-time and 3D quantification of the temporal evolution of a hyperthermic treatment of a target biological tissue.

[0003] The thermal treatment assembly and associated methods can be used during the intraoperative phase to display quantitative information in real time indicating the volume of induced temperature changes in the target area and / or areas adjacent to the target area. [Background technology]

[0004] It is known to locally treat diseased biological tissue by targeted administration of an energy source to increase (hyperthermia) or decrease (hypothermia) temperature. For example, energy can be provided by laser, microwave, radio frequency, focused ultrasound, or by cryotherapy.

[0005] Among these techniques, the first category of hyperthermia treatments is well known, consisting in the application of an energy dose to a target area of ​​biological tissue via a remotely located energy generator means (guided focused ultrasound or radio frequency waves) or by a percutaneous or vascular route (radio frequency, laser, microwave, cryotherapy). Most devices propose a given implementation that aims to reach a given volume a priori. However, the actual treated volume may vary substantially due to physiological / physiopathological parameters (perfusion, thermal diffusivity, energy absorption, presence of nearby large blood vessels, tissue and cellular heterogeneity).

[0006] The stage prior to the hyperthermia treatment, referred to as the "preoperative planning stage", is intended to assess the 3D extension of the affected area, thanks to suitable imaging techniques, for example by computed tomography (sometimes referred to throughout this specification as "TDM") or magnetic resonance imaging (sometimes referred to throughout this specification as "Magnetic Resonance Imaging, MRI"), which allows to determine the size, number, location and shape of the target areas.

[0007] During this pre-operative planning stage, global indicators of the dimensions of the areas to be treated, their number, and their relative location to identifiable anatomical landmarks are generally defined.

[0008] At the start of the treatment, the ballistic phase involves positioning the energy generator device opposite the area to be treated. Typically, this positioning is performed iteratively using intermittent imaging guidance.

[0009] During the treatment phase, energy deposition is generally performed using monitoring (ultrasound, physiological signals, sensors integrated into the treatment device) that does not allow accurate quantification of the 3D distribution of temperature in the area to be treated. In some specific cases, especially in MRI-guided focused ultrasound treatment, the temperature in the area to be treated is change is displayed globally and energy deposition can be interrupted if it deviates from the set value. From the temperature imaging it is possible to calculate thermal measurements that are reliable indicators of treatment, provided that the uncertainty in temperature measurement is less than 1°C at each pixel of the image.

[0010] In the absence of any temperature imaging modality, point measurements of temperature may be provided by invasive sensors (probes implanted in the tissue and / or treatment device).

[0011] Although hyperthermia techniques are much less invasive than surgery, they do have some limitations. One common problem with localized hyperthermia is the lack of real-time, 3D accurate monitoring of temperature in biological tissues.

[0012] The deviation between planned and actual energy deposition in different regions can be magnified due to trajectory errors, for example imperfect positioning of the energy applicator opposite the region to be treated.

[0013] As a result, the energy deposition may deviate substantially from the planned energy deposition.

[0014] One consequence of this effect is imperfect treatment associated with the risk of recurrence of the condition.

[0015] Likewise, there is an increased risk of altering healthy tissue in the area to be preserved, which could result in serious side effects.

[0016] As a result, the number of patients eligible for these minimally or non-invasive therapies is significantly reduced due to the lack of accurate intraoperative monitoring of the therapy.

[0017] The lack of precise, real-time 3D monitoring of the treatment makes it difficult to adjust these thermotherapy treatments, particularly precise repositioning of the energy applicator to complete the treatment with one or more additional successive energy applications in areas not yet treated. As a result, physicians are forced to evaluate the effectiveness of the treatment retrospectively, i.e., immediately after or several weeks after the treatment, thereby preventing optimal treatment in a single treatment, resulting in loss of efficiency and risk of missed opportunities for the patient.

[0018] Current methods do not offer accurate real-time monitoring of the area surrounding the area to be treated, thus increasing the risk of intra- and post-operative complications.

[0019] The present invention therefore aims to propose an assembly and a method that allows real-time monitoring in 3D and quantification of temperature during intraoperative treatment steps, covering the entire treated biological tissue and its surroundings, with a refresh rate of less than one second. Summary of the Invention [Problem to be solved by the invention]

[0020] The hyperthermia treatment assembly of the present invention allows for quantitative and dynamic monitoring of the treatment of the target biological tissue by proposing quantitative indicators related to the treatment. The hyperthermia treatment assembly of the present invention aims to improve the efficiency of hyperthermia treatments as well as their safety, thus increasing the benefit / risk balance of these hyperthermia therapies. Another anticipated result of the present invention is to increase the number of patients eligible for these therapies, which have fewer side effects than conventional surgery and are more efficient than drug treatments. [Means for solving the problem]

[0021] 1. A hyperthermia treatment assembly for a target region of biological tissue, comprising: a thermal energy generator; - coupled to said generator, change an energy applicator configured to apply thermal energy to the target area to induce - an MRI image acquisition device configured to generate at least one MRI anatomical image (IMG_IRM_A) and at least one phase image (IMG_IRM_P); a planning unit comprising MRI image processing means configured to define a target region Rc, a region to be preserved Rp and a neutral region Rn on said at least one MRI anatomical image (IMG_IRM_A), said MRI image processing means also configured to assign a heating treatment setpoint to each of the three regions and to assign an allowable temperature measurement uncertainty to each of the three regions; - a unit for monitoring the progress of the state of the warming treatment, configured to receive in real time during the warming treatment phase data originating from the planning unit and data originating from the MRI image acquisition device, said unit having means for generating a temperature image from said at least one phase image (IMG_IRM_P) and a temperature image shown on said temperature image; change and means for calculating an indicator of the state of the warming treatment in each of the three regions, means (12) for calculating a quantitative indicator of the state of the warming treatment, - spatially matching the MRI anatomical image with the temperature image generated during the heating procedure; - comparing the temperature and / or thermal mass associated with each pixel of the three regions with a predetermined heating treatment set point in each of the three regions; - determining the number of pixels that meet a predetermined warming treatment setting for each of the three regions, said number corresponding to a quantitative indicator of the warming treatment status in real time; - generating in real time a signal representative of the state of the warming treatment and the time evolution of quantitative indicators in three areas; A warming treatment assembly is provided that is configured to:

[0022] Thus, the physician can continuously track the evolution of the quantitative indicators in the three regions in real time during the warming treatment. The signals are presented, for example, in the form of a 2D or 3D map or a graphical representation. A dynamic display of the number of pixels that have reached a given temperature and / or thermal dose setpoint allows monitoring the progress of the treatment in the target region as well as in the preserved and neutral regions, and assists in making decisions in real time during the treatment.

[0023] The number of pixels in the target region that meet a predetermined thermal treatment setting may be compared to the number of predetermined pixels in the target region before treatment begins to provide a percentage of treated volume.

[0024] In the neutral region, the number of pixels that meet a predetermined heating treatment setting may be compared to a predetermined number of pixels in this region to provide a percentage of the changed volume, which ideally should remain as close to zero as possible.

[0025] In critical regions to be preserved, no pixel may violate predefined setpoints. It is therefore necessary to provide an early indicator of the risk of violating these instructions. As a result, a warning signal, e.g. an audible warning signal, may be given when, for example, 80% of the lethal thermal dose is reached in one or more pixels of this region, or when the temperature approaches within a few degrees of the permitted limit temperature.

[0026] In the neutral region, a warning signal may be given along with a similar or different warning signal, but is of less importance since violating the set point in this region is tolerable (although undesirable).

[0027] These warning signals allow the physician to be alerted in real time to the risk of making changes in the neutral and critical areas to be preserved before set values ​​in the neutral and critical areas to be preserved are reached or exceeded.

[0028] The signal indicating the status of the warming treatment occurring in real time with each new temperature measurement and thermal dose may be a visual or an audible signal indicating the treatment status in the three regions.

[0029] The features disclosed in the following paragraphs may be implemented as options. They may be implemented independently of each other or in combination with each other.

[0030] The assembly further includes a second image acquisition device configured to generate at least one anatomical image (IMG_A).

[0031] The planning unit further comprises an anatomical image processing means configured to define three regions on said anatomical image (IMG_A) and a recalibration means configured to spatially match the anatomical image with an MRI anatomical image resulting from an MRI image acquisition device.

[0032] The means for calculating the reliability indicator are determining the uncertainty of the measured temperature in each region from the temperature variance determined over the series of temperature images; - determining a number of pixels in each of the three regions that meet a predetermined acceptable temperature measurement uncertainty, said number being calculated based on the temperature measurement uncertainty shown on the thermal image; change and determining, corresponding to an indicator of reliability of the

[0033] According to one embodiment, the means for calculating a quantitative indicator of the state of the hyperthermia treatment comprises: change is configured to filter out pixels for which the quantitative indicators are not available or are unreliable, which makes it possible to increase the reliability of the quantitative indicators generated by the calculation means and in particular at the same time avoiding the generation of inadvertent warning signals during the procedure.

[0034] According to one embodiment, the heating treatment setpoint assigned to the target region Rc corresponds to a minimum temperature to be reached, a minimum amount of heat to be reached, or a predefined curve of the evolution of the temperature over time.

[0035] According to another embodiment, the heating treatment setpoint assigned to the region Rp to be saved corresponds to a maximum temperature that cannot be exceeded or a maximum thermal dose that cannot be exceeded.

[0036] According to yet another embodiment, the warming treatment setpoints assigned to the neutral zone correspond to a maximum temperature that cannot be exceeded or a maximum amount of heat that cannot be exceeded.

[0037] According to one embodiment, the energy applicator is a laser beam applicator, a microwave applicator, a radio frequency applicator, a focused ultrasound applicator, or a cryogenic energy applicator.

[0038] Advantageously, the assembly further comprises a display unit configured to display a quantitative indicator of the status of the treatment in each of the three regions.

[0039] According to another aspect, there is provided a method for real-time quantitative monitoring of a state of thermal treatment of living tissue implementing a thermal treatment assembly as defined above, comprising: - generating at least one MRI anatomical image; - defining a target region Rc, a region to be preserved Rp, and a neutral region Rn on said MRI anatomical image; - determining a first set of target pixels in said target region, a second set of pixels to be preserved in said region to be preserved Rp, and a third set of neutral pixels in said neutral region Rn; - assigning a heating treatment setting value to each of the pixels in the three regions Rc, Rp and Rn; - assigning an allowable temperature measurement uncertainty to each of the pixels in the three regions Rc, Rp and Rn; -Temperature shown on the thermal image change determining a confidence indicator of the three regions, said confidence indicator corresponding to a number of pixels in the three regions that satisfy a given uncertainty; - generating a temperature image from the phase image transmitted by the MRI image acquisition device; - calculating a quantitative indicator of the state of the warming treatment, said indicator corresponding to the number of pixels or the percentage of pixels that meet predefined warming treatment settings for each of the three regions Rc, Rp and Rn; - displaying in real time a 3D temperature map and a 3D thermal mass map, a quantitative indicator of the status of the heating treatment in each of the three regions.

[0040] According to one embodiment, the method further comprises a planning step carried out before the pretreatment step of the hyperthermia treatment, said planning step comprising: - generating at least one anatomical image (IMG_A); - defining on said anatomical image a target region Rc, a region to be preserved Rp and a neutral region Rn; determining a first set of target pixels in a target region, a second set of pixels to be preserved in said region to be preserved Rp, and a third set of neutral pixels in said neutral region Rn, The pre-processing stage further includes a step of recalibration between the anatomical image and the MRI anatomical image to define three regions on the MRI anatomical image.

[0041] Advantageously, the displaying step generates a visual and / or audio indicator that the warming treatment is complete in region Rc when the number of pixels in region Rc that meet the treatment setting value reaches a predetermined threshold.

[0042] Advantageously, the displaying step generates a visual and / or audio indicator that the safety setting within region Rp has not been adhered to when the number of pixels in the region to be preserved that do not meet the predetermined setting is greater than a predetermined threshold. [Brief description of the drawings]

[0043] Other features, details and advantages will become apparent from reading the following detailed description and examining the accompanying drawings. [Figure 1] FIG. 1 is a schematic representation of a thermal treatment assembly according to one embodiment. [Diagram 2] FIG. 13 is a schematic representation of a thermal treatment assembly according to another embodiment. [Diagram 3] 1 is a flow chart illustrating a method for monitoring a warming treatment according to one embodiment. [Figure 4] 11 is a flow chart illustrating a method for monitoring a warming treatment according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0044] In the context of the present invention, a "target area" should be understood as an area that includes the pathological tissue to be treated and is visible in imaging, as well as an area surrounding the pathological tissue. The vicinity around the pathological tissue is variable and is defined by the physician. The target area should undergo a temperature change to treat the pathological tissue. This area is indicated by Rc in FIG. 1.

[0045] In the context of the present invention, the "critical area to be preserved" should be understood as the area where the biological tissue is healthy and should not undergo harmful temperature changes during the hyperthermia treatment. This area is indicated by Rp in FIG.

[0046] In the context of the present invention, a "neutral zone" is to be understood as a zone in which biological tissue is healthy and ideally should not undergo temperature changes during a hyperthermia procedure. Nevertheless, possible temperature changes are not considered to be significant for the patient. This zone is indicated by Rn in FIG. 1.

[0047] In the context of the present invention, a 3D anatomical image is a reconstructed image that represents the anatomical structures of the target area and its environment. This 3D anatomical image can be obtained by different imaging techniques.

[0048] In the context of the present invention, a magnetic resonance imaging (MRI) device is a device configured to provide information about target regions, critical regions and neutral regions. This information may be anatomical and / or functional in nature and may in particular relate to the variations in temperature of the tissues contained in said regions. To do so, a magnetic resonance imaging device generates a 3D MRI image and assigns to each voxel (basic volume unit of each region) of the MRI image a complex number M·e φ where M is the modulus and φ is the phase of the magnetization vector in this voxel. In the following description and in the context of the present invention, the term "pixel" of an image denotes one or more pieces of information of the associated voxel. The module M at each pixel of the image allows the construction of an MRI anatomical image IMG_IRM_A. The phase difference between two successive MRI phase images IMG_IRM_P is directly proportional to the temperature difference, thereby allowing the construction of a temperature image.

[0049] In the context of this application, "thermal dose" corresponds to the integral of temperature over time. A thermal dose map can therefore be obtained from a temperature map. The temperature and thermal dose maps obtained during a treatment are indicators of the biological effect induced by the latter.

[0050] For the most part, the drawings and the following description include specific elements which may therefore be used to better understand the present disclosure as well as contribute to its definition, where applicable.

[0051] 1 represents an assembly 1 for a hyperthermia treatment of a treated target region Rc of living tissue according to an embodiment of the present invention. The assembly 1 comprises a hyperthermia treatment device having an applicator 2 coupled to a thermal energy generator 3, an MRI image acquisition device 4, a planning unit 5 (UNIT PLANIF1), a unit 9 (UNIT SURV) for monitoring the state of the hyperthermia treatment in real time by generating at least one quantitative indicator of the state of the hyperthermia treatment, and a display unit 13 (UNIT VIS).

[0052] The thermal energy applicator 2 is configured to induce a temperature change in the target area Rc of the living tissue to be treated. The thermal energy applicator 2 may consist of a radio frequency applicator, a microwave applicator, a focused ultrasound applicator, an applicator of a laser beam or a cryogenic energy applicator. In FIG. 1 a transdermal applicator is shown positioned in the target area Rc to be treated. The thermal energy applicator 2 is powered by an energy generator 3. The thermal energy applicator may also be in the form of a non-invasive external transmitter (focused ultrasound, guided radio frequency) adapted to focus the application of thermal energy to the target area.

[0053] The MRI image acquisition device 4 is used during a pre-treatment phase to generate an MRI anatomical image (IMG_IRM_A), which is performed immediately before the start of the heating procedure. The MRI anatomical image (IMG_IRM_A) is then transmitted to a planning unit 5.

[0054] The MRI image acquisition device 4 also acquires temperature data throughout the duration of the warming treatment. change The MRI imaging device 4 is used to generate a phase image (IMG_IRM_P) from a sequence of images sensitive to the temperature. The MRI imaging device 4 is configured to acquire dynamic temperature imaging covering three predetermined regions Rc, Rp and Rn throughout the duration of the heating procedure. This dynamic imaging is obtained using a fast acquisition sequence in the range of 1 second or less for each acquisition volume with a spatial resolution in the range of 1 millimeter or better. The phase image (IMG_IRM_P) is transmitted to the monitoring unit 9.

[0055] The planning unit 5 comprises means for processing an MRI anatomical image 6 (TRAIT IMG_IRM_A), which are configured to define on the 3D MRI anatomical image a target region Rc, a region of importance Rp to be preserved and a neutral region Rn.

[0056] For example, a biological tissue is represented diagrammatically in Figure 1 with a target region called Rc surrounded by a critical region to be preserved called Rp and a neutral region called Rn. The target region Rc should include the entire pathological region to be treated and does not include the critical region to be preserved.

[0057] According to one embodiment, the means 6 for processing the MRI anatomical image is capable of segmenting the 3D MRI anatomical image in order to determine target pixels in the region Rc, to determine pixels to be preserved in critical regions to be preserved, and to determine neutral pixels in neutral regions.

[0058] The means 6 for processing the MRI anatomical images is also configured to define a heating treatment instruction in each of the three regions. More specifically, the means 6 for processing the MRI anatomical images is configured to assign to each pixel of each of the three regions a temperature and / or thermal dose set point to be observed.

[0059] In the target region Rc, the heating treatment set point may be either a minimum temperature to be reached, or a minimum amount of heat to be reached, or a predefined curve of temperature change over time, or a combination of several temperature and heat amount set points.

[0060] In the critical region Rp to be maintained, the warming treatment set point can be either a maximum temperature that cannot be exceeded, or a maximum amount of heat that cannot be exceeded.

[0061] In the neutral region Rn, the warming treatment set point can be either a maximum temperature that cannot be exceeded, or a maximum amount of heat that cannot be exceeded.

[0062] According to one embodiment of the present invention, the means 6 for processing the MRI anatomical images is also configured to define an acceptable temperature measurement uncertainty in each of the three regions. More specifically, the means 6 is configured to assign to each of the pixels determined in each of the three regions Rc, Rp and Rn an acceptable uncertainty for the temperature measurement. The uncertainty value may be related to a predefined temperature set point. For example, a temperature of 5° C. change When is defined in region Rc, for example, it is not acceptable to have an uncertainty of more than 3°C.

[0063] An MRI anatomical image (IMG_IRM_A) with information associated with each of the three regions is transmitted to a monitoring unit 9 .

[0064] The associated information is the temperature and / or thermal setpoints assigned to each of the determined pixels in the three regions Rc, Rp and Rn, as well as the allowable temperature measurement uncertainties.

[0065] The monitoring unit 9 is configured to receive phase images (IMG_IRM_P) arising from the MRI image acquisition device 4 in real time during the heating treatment and to generate a quantitative indicator of the progress of the heating treatment from the MRI anatomical images (IMG_IRM_A) and the phase images (IMG_IRM_P) in real time during the heating treatment.

[0066] Advantageously, the monitoring unit 9 is also configured to receive measurements originating from an internal sensor (not shown in FIG. 1) integrated into the warming treatment device and from additional external sensors (not shown in FIG. 1). For example, the internal sensor may be a sensor integrated into the thermal energy applicator 2 and transmitting information about the position of the thermal energy applicator 2 in space relative to the target area, the thermal energy delivered by the applicator, and / or point measurements of temperature by a temperature sensor. For example, measurements originating from additional external sensors may include physiological measurements, such as measurements related to respiration, cardiac activity and patient position.

[0067] The monitoring unit 9 is configured to process the data it receives in real time, with a data analysis and processing speed that is superior to that of the acquisition of phase images by the MRI image acquisition device 4, and is configured to dynamically generate, with minimal latency, quantitative indicators representative of the progress of the state of the warming treatment during the treatment phase.

[0068] The monitoring unit 9 comprises means 10 for generating temperature images (IMGT) from the phase images (IMG_IRM_P) acquired by the MRI image acquisition device 4. The temperature image generating means 10 further comprises algorithms adapted to compensate for motion artifacts, time and space drifts of the MRI imaging device and also integrates an analysis of data originating from an external sensor of the warming treatment device and from additional sensors, e.g. physiological sensors.

[0069] The monitoring unit 9 comprises means for calculating a reliability indicator 11 of temperature measurements (FIAB). The temperature measurements show temperature variations shown on a temperature image generated from the MRI phase images. The calculation of the reliability indicator of the temperature measurements is performed before the application of energy by the energy applicator. The calculation means 11 is configured to determine the uncertainty of the temperature at each pixel, for example from the variance of the measured temperature over a series of several consecutive temperature images. For example, the series of images may include 10 consecutive temperature images in order to calculate the variance. According to an embodiment, the reliability indicator calculation means is capable of generating a 2D or 3D map representative of pixels that meet a predefined acceptable uncertainty in the planning unit 5. The calculation means 11 is capable of determining the reliability indicator, i.e. the number or percentage of pixels that meet a predefined uncertainty in the planning unit 5.

[0070] The reliability indicator calculation means 11 is arranged to compare the determined reliability indicator with a threshold value predefined by the physician.

[0071] According to a first configuration, if the reliability indicator is below a predefined threshold, the reliability indicator calculation means 11 is able to generate a control signal indicating that the temperature change shown on the temperature image is not reliable for calculating a quantitative indicator of the state of the warming treatment and for initiating monitoring of the warming treatment. The control signal is a visual and / or audible signal transmitted to the display unit 13. The monitoring process is stopped and the physician is not allowed to start the warming treatment.

[0072] According to a second configuration, if the reliability indicator is below a predefined threshold, the reliability indicator calculation means 11 generates a signal indicating that the temperature change shown on the temperature image is not reliable for calculating a quantitative indicator of the state of the warming treatment and for initiating monitoring of the warming treatment, the decision being nevertheless taken by the physician whether to initiate the warming treatment or not.

[0073] According to yet another configuration, if the reliability indicator is below a predefined threshold but remains within the tolerance range for the physician to continue the warming procedure, the reliability indicator calculation means 11 can generate a signal prompting the physician to modify the MRI image acquisition parameters and / or apply filtering to reduce the value of the variance of the measured temperatures. In this way, the physician can manually adjust different parameters to find acceptable temperature measurement conditions to start monitoring and perform the warming procedure.

[0074] The monitoring unit 9 comprises means 12 for calculating a quantitative indicator (IND QUANT) of the state of the warming treatment from the temperature images and the MRI anatomical images with associated information originating from the planning unit 5 .

[0075] In a first calculation step, the means 12 for calculating quantitative indicators determines the temperature and thermal mass in each of the pixels of the regions Rc, Rp and Rn. To do so, the calculation means spatially matches the MRI anatomical image generated before the heating procedure and the temperature image generated during the heating procedure resulting from the planning unit 5. In this way, the pixels defined in the three regions Rc, Rp, Rn on the MRI anatomical image and the pixels of the generated temperature image are associated.

[0076] According to the present invention, "spatial matching" of images should be understood as any operation consisting of matching at least two images in order to be able to compare or combine their respective information.

[0077] In a second calculation step, the quantitative indicator calculation means 12 determines in real time during the warming treatment the number or percentage of pixels that meet the predetermined treatment setpoints in the planning unit for the three regions Rc, Rp and Rn. The means 12 for calculating the quantitative indicators calculates, for each pixel on the temperature image, change The value of is compared to the temperature setpoint assigned to the pixels in the corresponding region.

[0078] In determining the number of pixels that meet the warming treatment setpoints, the calculation means 12 can exclude pixels that are considered not to have usable or reliable temperature measurements. For example, the excluded pixels have an uncertainty that is greater than a given uncertainty in the planning unit. According to another example, the excluded pixels have a signal-to-noise ratio with an absolute value close to zero and therefore an undefined phase. It is therefore not possible to give reliable information about the compliance with the setpoints at these pixels. This information is transmitted to the physician, who then decides to carry out the treatment.

[0079] Advantageously, the calculation means 12 are configured to obtain a processing speed for the data originating from the MRI imaging device 4 and from the planning unit 5 that is faster than the acquisition speed for the modulus and phase images, so as to be able to process the temperature images dynamically and without latency.

[0080] The monitoring unit 9 transmits all data at the output of the monitoring unit in real time to the display unit 13, such as temperature and thermal mass maps, quantitative indicators of the status of the heating treatment, as well as data from physiological sensors and sensors integrated into the heating treatment device, for real-time display to the physician so that the physician can monitor the progress of the heating treatment and decide to continue or possibly stop the heating treatment according to the status of the heating treatment corresponding to predetermined treatment set points.

[0081] According to one embodiment, the display of the quantitative indicators of the heating treatment can take various forms. For example, the pixels in the target region Rc that reach a defined temperature setpoint are represented with a predefined colorimetric coding, allowing a 2D or 3D visualization with high reading accuracy of the treated volume during the treatment. This information complements the display of the temperature map and the thermal dose that are superimposed on the MRI anatomical image.

[0082] The display unit 13 further comprises means for generating visual and / or audible indicators indicating: - the treatment is terminated in region Rc when the number of pixels in region Rc that meet the specified temperature setpoint within region Rc reaches a predetermined threshold; - the temperature setpoint in the region Rp is not observed, - The temperature setpoints within the region Rn are not respected.

[0083] FIG. 2 illustrates a thermal treatment assembly 20 according to another embodiment.

[0084] The hyperthermia treatment assembly 20 includes a hyperthermia treatment device including an applicator 2 coupled to a thermal energy generator 3, a device 4 for acquiring MRI images and generating a magnetic resonance image, an imaging device 21 for generating an anatomical image (IMG_A), a planning unit 25 (UNIT PLANIF2), a unit 9 (UNIT SURV) for monitoring the status of the hyperthermia treatment in real time by generating a quantitative indicator of the status of the hyperthermia treatment, and a display unit 13 (UNIT VIS).

[0085] Similar to the first embodiment, the thermal energy applicator 2 is configured to induce a temperature change in the target region Rc of the living tissue to be treated. The MRI image acquisition device 4 is used during the pre-treatment phase to generate MRI anatomical images (IMG_IRM_A) and phase images (IMG_IRM_P) during the heating procedure. The MRI anatomical images (IMG_IRM_A) are transmitted to the planning unit 25 and the MRI phase images (IMG_IRM_P) are transmitted to the monitoring unit 9.

[0086] For example, the imaging device 21 may be another MRI image acquisition device, a computed tomography (TDM) or an ultrasound examination (US). Thus, the anatomical image (IMG_A) may be generated before the day of the warming procedure, for example during the planning stage. The anatomical image may also be generated from a pre-computed 3D model, from the imaging data or other data, such as for example a 3D mapping of the cardiac electrical signal. The anatomical image (IMG_A) is transmitted by the imaging device 21 to the planning unit 25.

[0087] The planning unit 25 comprises an anatomical image processing means 22 (TRAIT IMG_A), a recalibration means 23 (RECAL) and means 24 for processing MRI images (TRAIT IMG_IRM).

[0088] The means 22 for processing the anatomical image is configured to define three regions Rc, Rp and Rn on the anatomical image IMG_A generated by the imaging device 21 during the planning stage. More specifically, the anatomical image processing means 22 is adapted to segment the anatomical image IMG_A to determine target pixels in the region Rc, to determine pixels to be preserved in the to be preserved region and to determine neutral pixels in the neutral region. The anatomical image IMG_A with the three delimited regions is transmitted to the recalibration means 23.

[0089] The recalibration means 23 is configured to spatially match the anatomical image (IMG_A) with the MRI anatomical image (IMG_IRM_A) generated just before the start of the procedure by the MRI imaging device 4, in order to define three regions Rc, Rp and Rn on the MRI anatomical image (IMG_IRM_A). The MRI anatomical image with the three defined regions is then transmitted to the MRI image processing means 24.

[0090] As in the first embodiment, the MRI image processing means 24 is configured to define heating treatment setpoints and acceptable temperature measurement uncertainties in each of three regions defined on the MRI anatomical image.

[0091] The MRI anatomical image (IMG_IRM_A) is then transmitted to the monitoring unit 9 with information associated with each of the three regions: the temperature and / or thermal setpoints assigned to each of the determined pixels in the three regions Rc, Rp and Rn, as well as the allowable temperature measurement uncertainties.

[0092] The operation of the monitoring unit 9 is identical to the first embodiment shown in FIG. 1 and described below, and will not be detailed here.

[0093] Similarly, the operation of the display unit 13 is identical to that of the first embodiment shown in FIG. 1 and described below.

[0094] The present invention also relates to a method for monitoring the status of a thermal treatment in real time and for supporting the physician's decision making by generating a quantitative indicator of the status of the thermal treatment in real time, in terms of treated volume relative to the total volume of the target area to be treated, which allows the physician to see the progress of the application of thermal energy and the treated volume over time. The method is carried out using a thermal treatment assembly according to the present invention, according to the steps described below.

[0095] The method of implementing the thermal treatment assembly of FIG. 1, shown in FIG. 3, is described above.

[0096] The method includes a pretreatment step and a warming treatment step.

[0097] During the pre-treatment stage, the planning unit 5 generates an MRI anatomical image (IMG_IRM_A) with three defined regions Rc, Rp and Rn and information associated with each of the determined pixels in the three regions. The information includes a predetermined treatment instruction for each of the three regions and a predetermined temperature measurement uncertainty in each of the three regions. This pre-treatment stage is performed immediately before the heating treatment stage.

[0098] During the treatment phase, the monitoring unit 9 calculates quantitative indicators regarding the state of the warming treatment from the data resulting from the pre-treatment phase and from the temperature images generated during the warming treatment.

[0099] The pre-treatment stage includes acquiring 101 a 3D MRI anatomical image of the target region and its environment. The 3D MRI anatomical image is obtained using an MRI imaging device 4.

[0100] The pre-processing stage includes step 102 of defining a target region Rc, a region of importance to be preserved Rp, and a neutral region on the MRI anatomical image.

[0101] The method includes determining pixels in each of the defined regions 103. This step includes segmenting the MRI anatomical image to determine a first set of target pixels in the target region, a second set of pixels to be preserved in the to be preserved region, and a third set of neutral pixels in the neutral region.

[0102] The method includes a step 104 of assigning to each of the pixels the temperature and thermal setpoint to be observed for each of the three defined regions.

[0103] The method includes a step 105 of assigning to each of the pixels an allowable uncertainty in the temperature measurement for each of three regions defined on the MRI anatomical image (IMG_IRM_A).

[0104] The MRI anatomical image, the defined temperature setpoints and the defined temperature measurement uncertainties in the three regions Rc, Rp and Rn are transmitted to the monitoring unit 5.

[0105] The method comprises a step of calculating a reliability indicator of the temperature measurement 106 before starting the warming procedure, i.e. immediately before the application of energy by the applicator 2. The temperature measurement reliability indicator calculation step comprises the following sub-steps: - generating a series of temperature images from phase images transmitted by the MRI imaging device 4, the phase images being acquired without applying thermal energy to the target area; - spatially matching the MRI anatomical image and the temperature image transmitted by the planning unit 5 to define three regions Rc, Rp, Rn on the temperature image; - determining the variance of the measured temperatures for each of the pixels in the three regions; - calculating the uncertainty of the temperature measurements from the variance at each pixel; - comparing the determined uncertainties of each of the three regions with the given uncertainties in the planning unit 5; - determining the number of pixels that satisfy a given uncertainty, said number being the temperature shown on the thermal image; change and expressing a reliability indicator of the

[0106] According to one embodiment, it is possible to generate a map representing three regions showing pixels that meet the uncertainty predefined by the planning unit and pixels that do not meet the uncertainty predefined by the planning unit.

[0107] The method comprises a step 107 of controlling a reliability indicator of the temperature measurement. In particular, the monitoring unit controls whether the reliability indicator of the temperature measurement is acceptable, i.e. whether the number of pixels fulfilling a given uncertainty is sufficient to start a warming treatment by means of a quantitative monitoring of the progress of the warming treatment performed by the monitoring unit 9.

[0108] According to one embodiment, if the reliability indicator calculated in step 106 is below a predefined threshold, the reliability indicator calculation means 11 calculates the temperature indicated on the thermal image. change However, they are not reliable for calculating quantitative indicators of the state of the warming procedure and initiating monitoring. change A control signal can be generated indicating that the physician is not allowed to start the warming treatment. This is the step that stops the treatment process 111.

[0109] According to yet another embodiment, if the reliability indicator is below a predefined threshold but remains within the tolerance range for the physician to continue the warming procedure, the reliability indicator calculation means 11 can generate a signal prompting the physician to modify the MRI image acquisition parameters and / or apply filtering to reduce the value of the temperature variance. In this way, the physician can manually adjust different parameters to find acceptable temperature measurement conditions for performing the warming procedure.

[0110] If the determined reliability indicator is greater than a physician-predetermined threshold, the physician may initiate the heating treatment. The monitoring unit 9 is also operated to monitor the progress of the state of the heating treatment in real time during the heating treatment. The monitoring unit 9 is synchronized with the heating treatment device that applies thermal energy to the target area so as to initiate the heating treatment in the target area simultaneously with monitoring the state of the heating treatment.

[0111] The monitoring phase therefore comprises a step 108 in which the generation of temperature images and the heating treatment are synchronized. The temperature images are generated from phase images transmitted by the MRI imaging device 4 to the monitoring unit 9 in real time during the heating treatment.

[0112] The monitoring phase includes a step of calculating in real time an indicator of the state of the warming treatment 109, which corresponds to the number of pixels that meet the predefined temperature setpoints for the three regions. To do so, the calculation means 12 spatially matches the generated MRI anatomical image before the warming treatment resulting from the planning unit with the temperature image generated during the warming treatment. In this way, the pixels defined in the three regions Rc, Rp, Rn on the three-dimensional MRI anatomical image are associated with the pixels of the generated temperature image. The temperature image generated during the warming treatment is compared pixel by pixel with the predefined temperature setpoints to determine the number of pixels that meet the predefined process setpoints for the three regions Rc, Rp and Rn.

[0113] According to one embodiment of the present invention, pixels that are deemed not to have usable or reliable temperature measurements are excluded when counting the number of pixels that meet the treatment setpoint.

[0114] The method includes a step 110 of displaying indicators of the state of the warming treatment in the three regions Rc, Rp and Rn. The indicators may be expressed in various ways, for example as pixels or volume processed or as a percentage of the volume of the region considered. These indicators are displayed in real time on the display interface to inform the physician of the progress of the state of the warming treatment. For example, pixels that have reached a temperature setpoint in the target region are represented with a predefined colorimetric coding, allowing a 2D or 3D visualization with a highly accurate reading of the treated volume during the treatment. A dynamic display of the number of pixels that have reached a predefined temperature setpoint allows the physician to monitor the progress of the treatment in the target region as well as in the regions to be preserved and in the neutral region, and assists in taking decisions according to the state of the warming treatment. The display interface also allows the display of 2D or 3D maps of temperature and thermal mass superimposed on the anatomical image.

[0115] According to one embodiment of the present invention, the monitoring unit 9 generates a visual or audio indicator that the warming treatment is complete when the number of pixels in the target area reaching a set value reaches a predetermined threshold (e.g., 100% of the number of pixels counted in the target area).

[0116] Similarly, the monitoring unit generates a visual and / or audio indicator signal when one or more pixels do not meet a set value within the region of interest Rp to be preserved or when the temperature approaches within a few degrees of an allowed limit temperature.

[0117] Similarly, the monitoring unit generates a visual and / or audio indicator signal when the number of pixels in the neutral region not conforming to the set value reaches a predefined threshold, for example when the percentage of the changed volume is close to 5%.

[0118] The method of the present invention for quantitatively monitoring the progress of the state of a hyperthermia treatment is carried out during the hyperthermia treatment and makes it possible to provide a mapping of the treated volume in real time.

[0119] Another embodiment of a method for implementing the thermal treatment assembly of FIG. 2, shown in FIG. 4, has been described above.

[0120] The method includes a planning step, a pretreatment step, and a warming treatment step.

[0121] The planning stage is performed before the day of the warming procedure and includes step 201 of acquiring a 3D anatomical image (IMG_A) by, for example, a TDM or US imaging device, or generated from imaging data from a pre-computed 3D model. During this planning stage, the physician also determines the characteristics of the target area, identifies the target area, and selects a suitable thermal energy applicator in order to plan the procedure.

[0122] The planning stage includes step 202 of defining on the 3D anatomical image by the anatomical image processing means 22 a target region Rc, a region of importance to be preserved Rp, and a neutral region Rn.

[0123] The planning stage includes a step 203 of determining target pixels in the target region Rc, pixels to be preserved in the region to be preserved Rp, and neutral pixels in the neutral region Rn.

[0124] The pretreatment step occurs immediately prior to the warming treatment.

[0125] The pre-treatment stage includes acquiring an MRI anatomical image 204 by an MRI imaging device 4 .

[0126] The pre-treatment phase includes a recalibration step 205 for spatially matching the anatomical image (IMG_A) acquired during the planning phase with the MRI anatomical image (IMG_IRM_A) to define three regions Rc, Rp, and Rn on the MRI anatomical image.

[0127] The pre-treatment stage includes step 206 of defining heating treatment settings in each of three regions defined on the MRI anatomical image (IMG_IRM_A), which is similar to step 104 of the method according to the first embodiment described above.

[0128] The pre-processing stage includes step 207 of defining temperature measurement uncertainties in each of three regions defined on the MRI anatomical image (IMG_IRM_A), which is similar to step 105 of the method according to the first embodiment described above.

[0129] Then the 3D MRI anatomical image (IMG_IRM_A) with the information associated with each of the three regions is transmitted to the monitoring unit 9 for the warming treatment phase, the information being the temperature and / or thermal dose setpoints and the allowed temperature measurements assigned to each of the pixels determined in the three regions Rc, Rp and Rn. The different steps forming the treatment phase are identical to those of the treatment phase of the method according to the first embodiment described above. [Industrial Applicability]

[0130] The thermal treatment assembly according to the present invention for quantitatively monitoring the application of thermal energy is particularly suitable for any type of treatment with localized temperature change, particularly where thermal energy is applied locally by laser, microwave, radio frequency, focused ultrasound or cryotherapy.

Claims

1. An assembly (1) for the thermal treatment of a target area of ​​living tissue, comprising: a thermal energy generator (3), - an energy applicator (2) coupled to said generator and configured to apply thermal energy to said target area to induce a temperature change; - an MRI image acquisition device (4) configured to generate at least one MRI anatomical image (IMG_IRM_A) and at least one MRI phase image (IMG_IRM_P); a planning unit (5) comprising MRI image processing means (6) configured to define the target region Rc, the region to be preserved Rp and the neutral region Rn on said at least one MRI anatomical image (IMG_IRM_A), said MRI image processing means (6) being configured to assign a heating treatment setpoint to each of said three regions and to assign an acceptable temperature measurement uncertainty to each of said three regions; a unit (9) for monitoring the evolution of the state of the warming treatment, configured to receive data from the planning unit (5) and from the MRI image acquisition device (4) in real time during a warming treatment phase, said monitoring unit (9) comprising means (10) for generating a temperature image from said at least one MRI phase image (IMG_IRM_P), means (11) for calculating a reliability indicator of the temperature changes shown on said temperature image, and means (12) for calculating an indicator of the state of the warming treatment in each of said three regions, said means (12) for calculating a quantitative indicator of said state of said hyperthermia treatment, - spatially matching the MRI anatomical image with the temperature image generated during the heating procedure; - comparing the temperature and / or thermal mass associated with each pixel of said three regions with a predetermined heating treatment set point in each of said three regions; - determining the number of pixels that meet the predetermined warming treatment settings for each of the three regions, said number corresponding to a quantitative indicator of the status of the warming treatment in real time; - generating in real time signals representative of said state of said hyperthermia treatment and of the temporal evolution of said quantitative indicators in said three areas; - comparing the number of pixels that meet the predetermined heating treatment setting value with the number of pixels in the target region Rc before the start of the heating treatment to provide the percentage of the heated volume; 23. An assembly configured to:

2. The assembly of claim 1 , further comprising a second image acquisition device (21) configured to generate at least one anatomical image (IMG_A).

3. 3. The assembly of claim 2, wherein the planning unit (25) further comprises an anatomical image processing means (22) configured to define the three regions on the anatomical image (IMG_A) and a recalibration means (23) configured to spatially match the anatomical image with the MRI anatomical image from the MRI image acquisition device (4).

4. The means (11) for calculating a reliability indicator - determining the uncertainty of the measured temperature in each region from the temperature variance determined over the series of temperature images; - determining a number of the pixels in each of the three regions that satisfy the predetermined acceptable temperature measurement uncertainty, the number corresponding to the reliability indicator of the temperature change shown on the temperature image.

5. 5. The assembly according to claim 1, wherein the means (12) for calculating a quantitative indicator of the state of the warming treatment is configured to exclude the pixels for which the measured temperature change is not usable or is unreliable.

6. 6. The assembly according to claim 1, wherein the heating treatment setting assigned to the target region Rc corresponds to a minimum temperature to be reached, a minimum amount of heat to be reached, or a curve of the evolution of the temperature over a given time.

7. 7. The assembly according to claim 1, wherein the heating treatment setpoint assigned to the region Rp to be preserved corresponds to a maximum temperature that cannot be exceeded or a maximum thermal dose that cannot be exceeded.

8. The assembly of claim 1 , wherein the heating treatment setpoints assigned to the neutral zone correspond to a maximum temperature that cannot be exceeded or a maximum amount of heat that cannot be exceeded.

9. 9. The assembly according to any one of claims 1 to 8, wherein the energy applicator (2) is a laser beam applicator, a microwave applicator, a radio frequency applicator, a focused ultrasound applicator, or a cryogenic energy applicator.

10. 10. The assembly according to any one of claims 1 to 9, further comprising a display unit (13) configured to display the quantitative indicator of the condition of the treatment in each of the three regions.

11. A method (100) for quantitatively monitoring the state of thermal treatment of living tissue in real time, implementing a thermal treatment assembly according to any one of claims 1 to 10, comprising: - generating (101) at least one MRI anatomical image; - defining (102) a target region Rc, a region to be preserved Rp and a neutral region Rn on said MRI anatomical image; - determining (103) a first set of target pixels in said target region, a second set of pixels to be preserved in said region to be preserved Rp, and a third set of neutral pixels in said neutral region Rn; - assigning (104) a heating treatment setting to each of the pixels in the three regions Rc, Rp and Rn; - assigning (105) an allowable temperature measurement uncertainty to each of the pixels in the three regions Rc, Rp and Rn; - determining (106) a reliability indicator of said temperature variation shown on the thermal image, said reliability indicator corresponding to the number of pixels in said three regions that meet said predetermined acceptable temperature measurement uncertainty; - generating a temperature image from the phase images transmitted by the MRI image acquisition device (108); - calculating (109) for each of the three regions Rc, Rp and Rn a quantitative indicator of the state of the warming treatment corresponding to the number of pixels or the percentage of pixels that meet the predefined warming treatment settings; - displaying (110) a 3D temperature map and a 3D thermal mass map, the quantitative indicators of the status of the hyperthermia treatment in each of the three regions in real time.

12. The method further includes a planning step performed before the pretreatment step of the warming treatment, the planning step comprising: - generating (201) at least one anatomical image (IMG_A); - defining (202) on the anatomical image the target region Rc, the region to be preserved Rp and the neutral region Rn; - determining (203) a first set of target pixels in said target region, a second set of pixels to be preserved in said region to be preserved Rp, and a third set of neutral pixels in said neutral region Rn, 12. The method of claim 11, wherein the pre-processing step further comprises a step (205) of recalibration between the anatomical image and the MRI anatomical image to define the three regions on the MRI anatomical image.

13. The method of claim 11 or 12, wherein the display step generates a visual and / or audio indicator indicating that the warming treatment is completed in the region Rc when the number of pixels in the region Rc that satisfy the warming treatment setting value reaches a predetermined threshold.

14. 14. The method of claim 11, wherein the displaying step generates a visual and / or audio indicator that the safety setting in the region Rp is not being respected if the number of pixels in the region to be preserved that do not meet the predetermined setting is greater than a predetermined threshold.

Images