WO2018024630A1

WO2018024630A1 - Device for positioning patients in radiotherapy treatments

Info

Publication number: WO2018024630A1
Application number: PCT/EP2017/069158
Authority: WO
Inventors: Carles Muñoz Montplet; Ingrid ROMERA MARTINEZ; Diego Jurado Bruggeman; Jordi Marruecos Querol; Salvador BOU SANCHEZ; Roger Grèbol Canal
Original assignee: Institut Català D'oncologia; Institut d'Investigació Biomèdica de Girona Dr. Josep Trueta (IDIBGI)
Priority date: 2016-08-03
Filing date: 2017-07-28
Publication date: 2018-02-08
Also published as: ES1165083U; ES1165083Y

Abstract

A device for positioning patients in radiotherapy treatments, comprising a positioning arm (2) capable of varying the distance (D) thereof with respect to a support base (3) configured to receive a patient (P), wherein said positioning arm (2) has at least one contact sensor (4) for generating one or more control signals (S1, S2, S3) upon contact with a patient (P), arranged between the support base (3) and the positioning arm (2), and maintaining said control signal or signals (S1, S2, S3) activated while in contact with the patient (P).

Description

DEVICE FOR POSITIONING PATIENTS IN RADIOTHERAPY TREATMENTS

Field of the invention

The present invention relates to a device for positioning patients in radiotherapy treatments in general, and especially in treatments in which patients must be irradiated in a deep inspiration breath hold position, maintaining said position during the irradiation process, such as in the treatment for left breast cancer or supradiaphragmatic Hodgkin lymphoma, among others. Background of the invention

The cardiotoxicity caused by radiotherapy treatments, particularly in treating left breast cancer, is well documented. The risk begins within a few years after radiotherapy treatment and continues for decades. The most recent data [Sara C. Darby et al: Risk of Ischemic Heart Disease in Women after Radiotherapy for Breast Cancer. New England Journal of Medicine; 368:987-98] suggest that the incidence of severe coronary toxicity increases linearly by 7.4% for each gray of mean cardiac dose, with no apparent dose threshold below which no toxicity is detected.

The implementation of radiotherapy techniques that reduce the dose the heart receives is highly important. However, the doses received by the lung and the contralateral breast should not be ignored because patient monitoring shows that there is a risk of pulmonary fibrosis, as well as lung cancer and contralateral breast cancer.

In radiotherapy treatments in which the patient must be irradiated in the Deep Inspiration Breath Hold Irradiation (DIBHI) position, the thoracic cavity expands and the anterior thoracic wall moves in the anterolateral direction. Furthermore, the diaphragm contracts and, as a result, the heart moves backward and toward the diaphragm. These modifications in the position of the organs increase the distance between the heart and the volume of the irradiation dose, which reduces the dose received by the heart.

All radiotherapy techniques that use breathing control to reduce toxicity to the heart are based on these arguments, since they do not affect the treatment in any way, as long as it may be repeated. In this way they help reduce toxicity to the heart.

To control breathing, patients are trained in deep breathing techniques and in holding their breath for up to 30 seconds. This process is usually repeated 3 to 6 times per visit. Currently, in order to ensure that the patient has sufficient deep breathing capacity at the moment of irradiation, there are devices on the market, which emit and detect infrared radiation, among others. These devices are positioned over the patient and synchronized with the electron accelerator to emit radiation only when the patient is in the correct position, previously defined by software provided by the manufacturer of the device. In order for these devices to function properly, a custom adjustment of the position of the infrared emitter is required for each patient, with the aim of correctly synchronizing the same with the electron accelerator.

The problem with this type of device, as well as others based on spirometers or surface tracking systems, is the high cost, in addition to the need for daily calibrations and periodic quality controls. Thus, often these solutions are not within the reach of most treatment centers.

The present invention consists of a simple and affordable device which enables reliably reproducing the positioning of a patient and deep inspiration breath hold on a daily basis, the aim of the invention being to direct the irradiation exclusively at the target volume, avoiding that other risk organs may be damaged by said radiation, and thereby minimizing the cardiotoxicity caused by radiotherapy treatments.

In addition, the device of the present invention accelerates radiotherapy treatment with maximum reliability and comfort, both for the nursing and technical staff, as well as for the patients, it being easier to adjust on the patient, providing contact and visual reference of the amplitude of the deep inspiration breath hold, quickly detecting situations in which patients do not have a proper position or deep inspiration breath hold, as well as stopping the irradiation the moment this occurs. Description of the invention

The device for positioning patients in radiotherapy treatments of the present invention comprises a positioning arm capable of varying the distance thereof with respect to a support base configured to receive a patient. In turn, said positioning arm has at least one contact sensor which allows generating one or more control signals upon contact with a patient arranged between the support base and the positioning arm, and maintaining said control signal or signals activated while in contact with the patient.

The control signals are mainly luminous, acoustic and/or electric, controlled by an electric circuit associated with the contact sensor. They preferably serve to warn and/or inform both the staff and the patient with regard to whether the deep inspiration breath-hold technique is being performed correctly or not. Specifically, a correct inspiration occurs when the patient's chest is kept in contact with the sensor during the time established by the specialist, having previously adjusted the positioning arm, with the patient arranged on the support base (stretcher, treatment table, etc.). According to a preferred operating mode, once the patient is in the correct position, the device begins to emit a luminous signal and an acoustic signal, which serve as a reference for the patient and the radiotherapy technicians to know that the patient is in the correct position. Said signals remain active while the sensor detects contact with the patient. Each time said contact is lost, the device ceases to emit signals, so that the patient can correct their position, and/or so that the expert may act as they feel is most appropriate. However, there are many other options for carrying out this operating mode, for example, inversely to the case previously described, combining the signals in a different way, using different colors and/or sound tones as reference for each of the positions, etc.

Likewise, the signals can also be used, either independently or in combination, to activate or deactivate other complementary safety devices.

Among the different contact sensors that may be used in the device of the present invention, a force sensor is preferably used with a long and thin configuration in the form of a strip, which is capable of adhering to the lower face of the positioning arm by adhesive means. Nevertheless, it is also possible to use contact sensors such as limit switches conveniently arranged on said positioning arm.

Likewise, for the purpose of not interfering with radiotherapy treatment, most of the components of the device, and particularly all those that may interfere in the radiation field, are made of radiolucent materials, such as carbon fiber, fiberglass, quartz, or other equivalent radiolucent materials.

According to a preferred embodiment, the positioning arm comprises:

• a fixed bar able to be coupled to the support base; and

· a movable bar, in which is a contact sensor is arranged, joined to the fixed bar and configured to move along the same, maintaining a position parallel to the support base.

Preferably, the positioning arm has an L-shaped configuration, wherein the fixed bar is arranged in a vertical position, while the movable bar is arranged in a horizontal position, forming a 90° angle with respect to the fixed bar and parallel to the support base.

In order to facilitate the movement of the movable bar, the bar comprises a sliding carriage configured to move along a longitudinal rail, arranged on the fixed bar. At the same time, said carriage allows maintaining the movable bar secured to the fixed bar, preventing them from separating from one another.

In turn, the positioning arm comprises a retaining element, which enables fixing the vertical position of the movable bar with respect to the fixed bar once the desired distance is reached. To facilitate handling of the device, said retaining element preferably has a threaded pin with a knob at the end thereof, which facilitates handling with the hand, such that the action of screwing/unscrewing allows joining or releasing the movable bar with respect to the fixed bar.

In order to enable the user of the device to accurately know the value of the distance of the positioning arm with respect to the support base, the fixed bar comprises a graded length scale arranged according to the direction of the movement of the movable bar, and that allows choosing the fastening point with a margin of less than 1 mm.

The device for the positioning of patients in radiotherapy treatments of the present invention allows an operation based exclusively on the supervision of an expert, guided in turn by luminous and/or acoustic control signals. However, as mentioned above, said device may work in conjunction with other complementary safety systems or devices.

To this end, the movable bar comprises an auxiliary mechanism configured to couple an infrared reflective device, synchronized with an electron accelerator. Preferably, said auxiliary mechanism comprises:

· a mounting base configured to be secured to the movable bar above the contact sensor, with the aim of ensuring that it is not placed between the patient's chest and said contact sensor;

• a positioning guide having an upper end joined to the infrared reflective device and a lower end, configured to move vertically with respect to the mounting base, so as to enable the lower end to be brought from a lower position located below the contact sensor to an upper position located at the height of the contact sensor; and

• a guiding groove configured to receive a guiding pivot joined to the positioning guide, which enables delimiting the vertical displacement of the positioning guide and prevents the rotation thereof.

On the other hand, it should be noted that the positioning arm can be directly coupled to a support base, formed by a stretcher, treatment table, etc. or indirectly through a support base integrated in the device itself and configured to be coupled to said stretcher or treatment table. In any case, the support base must be made of materials that provide the necessary resistance, preferably radiolucent materials, such as carbon fiber.

In any case, the positioning arm has the particular feature of being removable with respect to the support base. In other words, it may be easily mounted on the support base and subsequently removed. In turn, the device can easily be coupled to any type of stretcher or treatment table. This is especially practical for significantly reducing preparation time prior to starting treatment. Specifically, once the device has been adjusted for a specific patient during the planning session (simulation session), said adjustments can be reproduced in subsequent treatment sessions, without having to repeat the initial adjustment process. To this end, images are usually taken by means of computerized axial tomography (CAT) during said planning session in order to obtain an anatomical record of the patient, and a tattoo is also made to mark the horizontal position of the positioning arm. Said tattoo is carried out with the movable bar in contact with the patient on the cranial side and without inspiration. Subsequently, the value of the vertical distance of said arm with respect to the support base is noted, with the patient in a deep inspiration breath hold position. In subsequent treatment sessions, the technical staff only has to follow these indications to reproduce the exact position between the patient and the device.

Thus, it is necessary to establish a fixed relative position between the support base and the positioning arm. To this end, the fixed bar comprises a coupling element which allows said fixed bar to be coupled to a fixed position of the support base, as well as the subsequent decoupling thereof. In turn, the support base comprises a receiving element, which allows fitting the coupling element and the subsequent removal thereof.

In order to fix the support base on any type of stretcher or treatment table, and subsequently be able to remove the same, the support base preferably comprises an anchoring mechanism that can be easily manipulated without using tools. For this purpose, the anchoring mechanism comprises:

• a first lateral stop located at a first end of the support base; and

• a second lateral stop located at a second end of the support base, wherein said second lateral stop forms a cam, configured to rotate with respect to a rotation axis by means of the rotation of a handle joined thereto.

The rotation of the cam allows increasing or reducing the horizontal distance between the first lateral stop and the second lateral stop, depending on the direction of rotation of the handle. Thus, by rotating the handle in one direction, the stops move toward one another to fasten the support base to the stretcher or treatment table, while in the opposite direction they move away from one another in order to release the same. This makes the use of the device compatible with stretchers or treatment tables of different widths.

Brief description of the drawings

What follows is a very brief description of a series of drawings that aid in better understanding the invention, and which are expressly related to an embodiment of said invention that is presented by way of a non-limiting example thereof.

Figure 1 shows a perspective view of the device of the present invention.

Figure 2 shows a first elevation view of Figure 1 , with the positioning arm arranged in an upper position.

Figure 3 shows a second elevation view of Figure 1 , with the positioning arm arranged in a lower position.

Figure 4 shows a partial bottom view of the movable bar.

Figure 5 shows a cross-section view along line A-A of Figure 6.

Figure 6 shows a plan view of Figure 5. Figure 7 shows a rear view of Figure 2.

Figure 8 shows a cross-section view along line B-B of Figure 7.

Figures 9a and 9b show an example of application of the device of the present invention.

Detailed description of the invention

As can be seen in Figure 1 , the device of the present invention comprises a positioning arm (2) capable of varying the distance (D) thereof with respect to a support base (3) configured to receive a patient (P), wherein said positioning arm (2) has at least one contact sensor (4), as shown in Figures 2-4, which enables generating one or more control signals (S1 , S2, S3) upon contact with a patient (P), arranged between the support base (3) and the positioning arm (2), and maintaining said control signal or signals (S1 , S2, S3) activated while in contact with the patient (P).

According to the present example, the contact sensor (4) allows generating a luminous control signal (S1 ) through a luminous indicator (5) arranged on the device (1 ) itself. Said luminous indicator (5) turns on or off depending on whether the position of the patient (P) is correct or not. In turn, the contact sensor (4) also allows generating an acoustic control signal (S2) through an acoustic indicator (6), which produces a sound when the position of the patient (P) is correct. The acoustic indicator (6) is also located in the device (1 ) so that it is more compact, autonomous and functional. However, in other possible embodiments said indicators (5, 6) may be separate from the device (1 ), forming part of a fixed installation of the treatment facility, conveniently located to allow their correct visualization and/or perception, and receiving the signals (S1 , S2, S3) wirelessly or by means of wiring from the device (1 ).

Likewise, the contact sensor (4) is configured to generate an electric control signal (S3) through an electric contact, in this case located in the control box and/or power supply unit (7) of the device (1 ), and which may be integrated into an electric control and/or power circuit. This electric contact can be used in many different ways, such as: to activate or deactivate other devices and/or indicators, or as an electrical safety interlock, etc.

According to the present example, the constructive configuration of the device (1 ), which allows varying the distance (D) is based on a positioning arm (2) made from carbon fiber, comprising:

• a fixed bar (21 ) able to be coupled to the support base (3); and

• a movable bar (22), in which a contact sensor (4) is arranged, joined to the fixed bar (21 ) and configured to move along the same, maintaining a position parallel to the support base (3).

As can be seen, the positioning arm (2) has an L-shaped configuration, wherein the fixed bar (21 ) is arranged in a vertical position, while the movable bar (22) is arranged in a horizontal position, forming a 90° angle with respect to the fixed bar (21 ) and parallel to the support base (3).

The positioning arm (2) is removable with respect to the support base (3). In other words, it may be easily mounted on the support base (3) and subsequently removed. To this end, the fixed bar (21 ) comprises a coupling element (28) which allows said fixed bar (21 ) to be coupled to a pre-established position (XYREF) of the support base (3), as well as to allow for the subsequent decoupling thereof. In turn, the support base (3) comprises a receiving element (31 ), which allows fitting the coupling element (28) and the subsequent removal thereof. For greater convenience of the technical staff, the coupling element (28) and the receiving element (31 ) are joined by means of screws or pins (29), which can be manipulated without tools.

According to the present example, the device (1 ) is adapted to work in conjunction with a complementary safety device. To this end, the movable bar (22) comprises an auxiliary mechanism (27) configured to couple an infrared reflective device (100) synchronized with the electron accelerator of the radiotherapy device to emit radiation only when the patient (P) is in the correct position.

Figures 2 and 3 show two elevation views with the positioning arm (2) arranged in different vertical positions, in order to show how the distance (D) thereof varies with respect to the support base (3). In Figure 2, the positioning arm (2) is located at a first distance (Di) further away from the support base (3) while in Figure 3 it is located at a second distance (D2) closer thereto.

Figure 4 shows the arrangement of the contact sensor (4) in greater detail. According to the present example, a force sensor with a long and thin configuration in the form of a strip is used, which is capable of adhering to the lower face of the positioning arm (2) by adhesive means.

As shown in Figure 5, in order to facilitate the movement of the movable bar (22), the bar comprises a sliding carriage (24) configured to move along a longitudinal rail (23), arranged on the fixed bar (21 ). At the same time, said carriage (24) allows maintaining the movable bar (22) secured to the fixed bar (21 ), preventing them from separating from one another.

In turn, the positioning arm (2) comprises a retaining element (25), which enables fixing the vertical position of the movable bar (22) with respect to the fixed bar (21 ) once the desired distance (D) is reached. Said retaining element (25) preferably has a threaded pin (251 ) with a knob (252) at the end thereof, such that the screwing/unscrewing thereof allows joining or releasing the movable bar (22) with respect to the fixed bar (21 ).

As shown in Figures 6 and 7, in order to fasten the support base (3) on any type of stretcher or treatment table (M), and subsequently be able to remove the same, the support base (3) preferably comprises an anchoring mechanism (32) that can be easily manipulated without using tools. For this purpose, the anchoring mechanism (32) comprises:

• a first lateral stop (33) located at a first end (3a) of the support base (3); and

· a second lateral stop (34) located at a second end (3b) of the support base (3), wherein said second lateral stop (34) forms a cam (35), configured to rotate with respect to a rotation axis (Z34) by means of the rotation of a handle (36) joined thereto.

The rotation of the cam (35) allows increasing or reducing the horizontal distance between the first lateral stop (33) and the second lateral stop (34), depending on the direction of rotation of the handle (36). Thus, by rotating the handle (36) in one direction, the stops (33, 34) move toward one another to fasten the support base (3) to the stretcher or treatment table (M), while in the opposite direction they move away from one another in order to release the same.

The handle (36) comprises a push button (37), which allows decoupling the rotation of the handle (36) from the cam (35), in order to avoid interference with a possible electron accelerator or (CAT) scanner. Thus, once the support base (3) is fixed, the push button (37) can be pressed so that the handle (36) rotates freely with respect to the cam (35), gathering it within the area defined by the stretcher or treatment table (M), as shown in Figure 9b.

In order to enable the user of the device (1 ) to accurately know the value of the distance (D) of the positioning arm (2) with respect to the support base (3), the fixed bar (21 ) comprises a graded length scale (26) arranged according to the direction of the movement of the movable bar (22), which interacts with a pointer (261 ) joined to the same.

Figure 8 shows the auxiliary mechanism (27) in greater detail, allowing the integration of the infrared reflective device (100). Said auxiliary mechanism (27) comprises:

• a mounting base (271 ) configured to be secured to the movable bar (22) above the contact sensor (4) with the aim of ensuring that it is not placed between the patient's (P) chest and said contact sensor (4);

• a positioning guide (272) having an upper end (2721 ) joined to the infrared reflective device (100) and a lower end (2722), configured to move vertically with respect to the mounting base (271 ), so as to enable the lower end (2722) to be brought from a lower position (Yi) located below the contact sensor (4) to an upper position (Ys) located at the height of the contact sensor (4); and

• a guiding groove (273) configured to receive a guiding pivot (2723) joined to the positioning guide (272), which enables delimiting the vertical displacement of the positioning guide (272) and prevents the rotation thereof.

The auxiliary mechanism (27) is completed with a separator (274), which allows limiting the downward movement of the positioning guide (272), preventing the guiding pivot (2723) from coming out of the guiding groove (273). Likewise, it is also possible to orient the reflectors (101 ), arranging them in the opposite direction to the position shown in Figure 7, after rotating the infrared reflective device (100) 180° in craniocaudal direction, and subsequent fastening thereof in the desired orientation.

The auxiliary mechanism (27) can be mounted in a symmetrical arrangement to that shown in Figure 8. To this end, simply loosen the screw (275), remove the auxiliary mechanism (27) completely, rotate it 180° and mount it once again on the movable bar (22).

Figures 9a and 9b show the operating mode of the device (1 ) of the present invention, comprising the following steps:

a) Placing the support (3) on the treatment table (M), approximately at mid-back of the patient (P).

b) Lying the patient (P) on the treatment table (M).

c) Fastening the positioning arm (2) in an inverted "L" arrangement and horizontally moving the entire device (1 ) until it reaches the patient's mark/tattoo.

d) Fastening the device (1 ) to the table (M) using the anchoring mechanism (32).

e) Positioning the movable bar (22) at the indicated height for the patient in question (the height recorded after performing the adjustment process in the previous session), using the graded length scale (26) arranged on the fixed bar (21 ).

f) Fastening the movable bar (22) to the fixed bar (21 ) at the indicated height by rotating the retaining element (25).

g) Electrically connecting the device (1 ).

h) Activating the luminous indicator (5) and the acoustic indicator (6) by means of a switch located on the control box and/or power supply unit (7).

i) Placing the infrared reflective device (100) on the movable bar (22), using the auxiliary mechanism (27).

Claims

1 A device for positioning patients in radiotherapy treatments, said device (1 ) characterized in that it comprises a positioning arm (2) capable of varying the distance (D) thereof with respect to a support base (3) configured to receive a patient (P), wherein said positioning arm (2) has at least one contact sensor (4) for generating one or more control signals (S1 , S2, S3) upon contact with a patient (P), arranged between the support base (3) and the positioning arm (2), and maintaining said control signal or signals (S1 , S2, S3) activated while in contact with the patient (P).

2. The device according to claim 1 , characterized in that the contact sensor (4) allows generating a luminous control signal (S1 ) through a luminous indicator (5).

3. The device according to any of claims 1 to 2, characterized in that the contact sensor (4) allows generating an acoustic control signal (S2) through an acoustic indicator (6).

4. The device according to any of claims 1 to 3, characterized in that the contact sensor (4) is configured to generate an electric control signal (S3) through an electric contact.

5. The device according to any of claims 1 to 4, characterized in that the contact sensor (4) is a force sensor.

6. The device according to any of claims 1 to 5, characterized in that the positioning arm (2) is made of radiolucent material.

7. The device according to any of claims 1 to 6, characterized in that the positioning arm (2) comprises:

• a fixed bar (21 ) able to be coupled to the support base (3); and

8. The device according to claim 7, characterized in that the fixed bar (21 ) comprises a longitudinal rail (23) and in that the movable bar (22) comprises a sliding carriage (24) configured to move along the longitudinal rail (23).

9. The device according to any of claims 7 to 8, characterized in that the positioning arm (2) comprises a retaining element (25) for fixing the position of the movable bar (22) with respect to the fixed bar (21 ) once the desired distance (D) is reached.

10. The device according to any of claims 7 to 9, characterized in that the fixed bar (21 ) comprises a graded length scale (26) which allows knowing the value of the distance (D).

1 1. The device according to any of claims 7 to 10, characterized in that the movable bar (22) comprises an auxiliary mechanism (27) configured to couple an infrared reflective device (100), synchronized with an electron accelerator.

12. The device according to claim 1 1 , characterized in that the auxiliary mechanism (27) comprises:

• a mounting base (271 ) configured to be secured to the movable bar (22) above the contact sensor (4);

· a positioning guide (272) having an upper end (2721 ) joined to the infrared reflective device (100) and a lower end (2722), configured to move vertically with respect to the mounting base (271 ), so as to enable the lower end (2722) to be brought from a lower position (Yi) located below the contact sensor (4) to an upper position (Ys) located at the height of the contact sensor (4); and

· a guiding groove (273) configured to receive a guiding pivot (2723) joined to the positioning guide (272), which enables delimiting the vertical displacement of the positioning guide (272) and prevents the rotation thereof.

13. The device according to any of claims 7 to 12, characterized in that the fixed bar (21 ) comprises coupling element (28) for coupling said fixed bar (21 ) to a pre-established position

(XYREF) of the support base (3), as well as allowing subsequent decoupling thereof.

14. The device according to claim 13, characterized in that the support base (3) comprises a receiving element (31 ) for fitting the coupling element (28) and for the subsequent removal thereof.

15. The device according to any of claims 1 to 14, characterized in that the support base

(3) comprises an anchoring mechanism (32) configured to fasten said support base (3) to a treatment table or stretcher (M).

16. The device according to claim 15, characterized in that the anchoring mechanism (32) comprises:

• a second lateral stop (34) located at a second end (3b) of the support base (3), wherein said second lateral stop (34) forms a cam (35), configured to rotate with respect to a rotation axis (Z34) by means of the rotation of a handle (36) joined thereto.