WO2017142747A1

WO2017142747A1 - Prone breast board for high-dose-rate partial breast irradiation brachytherapy

Info

Publication number: WO2017142747A1
Application number: PCT/US2017/016868
Authority: WO
Inventors: Jiaju ZHANG
Original assignee: Zhang Jiaju
Priority date: 2016-02-16
Filing date: 2017-02-07
Publication date: 2017-08-24

Abstract

The present invention discloses a radiation-shielding device, one-piece-inclination-adjustable board with at least one multileaf collimator and with a raised standing platform, and a prone breast treatment equipment. The shielding device comprises at least one radiation-shielding wall and at least one slidable shielding plate capable of properly pushing against a patient's breast after the breast has been inserted. The radiation shielding device is capable of reducing the amount of harmful radiation reaching unintended organs during a high-dose-rate brachytherapy for partial breast irradiation of breast cancer treatment.

Description

Prone Breast Board for High-Dose-Rate Partial Breast Irradiation Brachytherapy

BACKGROUND OF THE INVENTION

1 . Field of the Invention

The present invention generally relates to a medical support device, or a prone breast treatment equipment, capable of shielding radiation during high-dose-rate brachytherapy for partial breast irradiation to treat breast cancer. Specifically the present invention relates to a radiation-shielding device and a prone breast treatment equipment comprising the radiation shielding device capable of reducing harmful radiation reaching unintended organs during the high-dose-rate brachytherapy for partial breast irradiation of breast cancer treatment.

2. Description of the Prior Art

Breast cancer remains the most commonly diagnosed cancer and the second leading cause of cancer death among women in the United States. In the year 2016, estimated 246,660 new cases of breast cancer were diagnosed and 40,450 women died from it. A study revealed a significantly higher 15-year mortality rate from heart disease and secondary lung cancer among breast-cancer patients treated with radiation. Furthermore, another study revealed that more patients treated for left breast cancer died from heart disease than those treated for right breast cancer. There are two main types of radiation therapy, external beam and brachytherapy. The external beam radiation treatment applies a focused radiation beam outside of the breast. The brachytherapy uses a 4π un-focused high-dose-rate radiation source inserted inside the cavity of the targeted breast.

Radiation is known to cause damages to organs if the dosage is too high. It has been found that many patients developed heart failure or lung disease years after a conventional partial breast irradiation (PBI) treatment where a patient lies down in a supine (face-up) position for radiation treatment without any protection from radiation. To address this issue, radiation treatments involving prone (face-down) positions on prone breast boards have been disclosed in various patents and patent applications. Examples are US Pat. No. 7763864, US Pat. No. 7526066, US Pat. No. 5564438, US Pat. No. 8146186, US Pat. No. 8218723, US Pat. No. 8374312, US Pat. No. 8964936, US Pat. Appl. No. 2003/0004454, US Pat. Appl. No. 20090080604, WO201 197726, and WO2008106468. When a person lies down in the prone position, the radiation received by other unintended organs can be reduced since the distance between the breast and other body parts such as chest wall, heart and lung is further away than if the person is in a supine position. However, even in the prone position, the radiation received by other unintended organs such as heart and lung during treatment may still be excessive and damaging, especially if the high-dose-rate brachytherapy is used. The radiation shielding mechanisms in current arts are insufficient, expensive, or inconvenient.

US Pat. No. 7763864 was directed to external beam radiation treatments method and mentioned only a breast panel without any details regarding shielding of the unintended breast from the radiation while treating the targeted breast. In addition, the treatment table is in an elevated position and it may not be easy for some patients to get into the proper position.

US Pat. No. 7526066, also directed to external beam radiation treatments, disclosed a shielded table without a multileaf collimator and a beam stop/shielded base that can substantially absorb scattered radiation. In order to shield the source and the patient according to the disclosure, it would require a shielded table of full body length and a large shielded enclosure to enclose the radiation source, its path, and space around the breast to be treated. To do all these, it requires a large amount of shielding material and it is heavy and expensive. Furthermore, the one breast hole design is not comfortable for the other unintended breast while lied down.

US Pat. No. 8218723 disclosed a radiation shield during a breast radiation therapy in a leaning position of a standing patient using an external radiation. It didn't disclose any details about the design of the radiation shield. The radiation shield has a bottom section to shield, e.g., the hips and legs.

US Pat. No. 8374312, also directed to an external beam radiation treatment, disclosed a radiotherapy couch with a U-shaped opening for a breast to insert through. However, it didn't mention how to shield radiations.

The present invention is related to a high-dose-rate PBI brachytherapy in prone position for breast cancer treatment. Since the radiation is a 4π un-focused radiation and the dosage rate is high, it requires a special shielding mechanism to minimize the radiation hitting the unintended breast, heart, lung, or other organs. Since targeted breast of a patient undergoing the high-dose-rate PBI brachytherapy always has catheters or needles tethered to it, it also requires a special design to facilitate the insertion of the breast with the tethered catheters or needles into the breast hole. Therefore, there is a need for an economical and effective device that can minimize the radiation dosage received by unintended organs during high-dose-rate brachytherapy for breast cancer treatment.

SUMMARY OF THE INVENTION

The present invention relates to a radiation shielding device comprising at least one partially open shielding wall and at least one slidable shielding plate made of lead or other radiation absorbing material (such as a tungsten alloy) wherein the shielding device is capable of shielding the radiation emitted during a PBI treatment using a prone breast board, when the breast to be treated is placed inside the compartment of the shielding device, so that the radiation escaped from the shielding device, harmful to heart, lung, and other organs, is minimized. In addition, the present invention also relates to a prone breast treatment equipment comprising a shielding device of the present invention. Furthermore, the present invention also relates to a method of shielding radiations during PBI treatment comprising a patient standing on a raised platform on a one-piece-inclination-adjustable board, inserting the breasts to the breast hole cutouts on the one-piece-inclination- adjustable board, lowering the one-piece-inclination-adjustable board by a machine to a horizontal position, a medical personnel fitting the slidable shielding plate(s) and shielding walls against the breast to minimize the opening, and a medical personnel performing the PBI treatment.

Other objects and advantages will become apparent to those skilled in the art from the following detailed description in conjunction with the appended claims and drawings attached hereto. BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a prospective view of a radiation-shielding device of the present invention. Fig. 2 is a prospective view of the radiation-shielding device in Fig. 1 with a slidable shielding door.

Fig. 3 is an assembly view, in prospective, of a prone breast treatment equipment comprising the radiation shielding device of Fig. 2, a upper section, a middle section, and a lower section.

Fig. 4 is prospective view of a prone breast treatment equipment of Fig. 3.

Fig. 5 is a prospective view of a prone breast treatment equipment comprising two open breast holes.

Fig. 6 is a prospective view of a radiation-shielding device with a pair of slidable plates with curved edges.

Fig. 7 is a prospective view of a prone breast treatment equipment with a one-piece- inclination-adjustable board in an upright position.

Fig. 8 is a prospective view of a prone breast treatment equipment of Fig. 7 viewed from a different angle.

Fig. 9 is a prospective view of a prone breast treatment equipment of Fig. 7 in an inclined position.

Fig. 10 is a prospective view of a prone breast treatment equipment with a one-piece- inclination-adjustable board in a horizontal position.

Fig. 11 is a prospective view (top view) of the middle section of the prone breast board with multileaf collimators before breast insertion.

Fig. 12 is a prospective view of Fig. 1 1 viewed from below.

Fig. 13 is a prospective view (top view) of Fig. 1 1 after the multileaf collimators have been moved towards the breasts.

DETAILED DESPCRIPTION OF THE INVENTION

The drawings or figures are for illustration purpose only. In all figures, like numbers refer to similar parts. The drawings are not necessarily drawn in scale.

Referring to Fig. 1a, there is an illustration of an embodiment of a radiation shielding device comprising a half cylindrical shielding wall 1 , two slidable plates 2, two knobs 3 for controlling the movement of the two slidable plates 2, two front supporting poles 4, two rear supporting poles 5, one pinion housing 6 fixed to the each of the rear supporting pole 5, a middle cross beam 7, and a supporting frame 8. The shielding wall 1 can also take other shapes such as a "U" shape as long as there is an opening on the side of the wall. The side opening is important because the targeted breast for high-dose-rate

brachytherapy always has tethered catheters or needles to be connected to a long radiation delivery tube (or applicator) from the radiation-generating machine. The side opening allows medical personnel to make the connection between the tethered catheters or needles and the radiation delivery tube easily. The shielding wall 1 is secured by the front supporting pole 4, the rear supporting pole 5, the supporting frame 8, and the middle cross beam 7. The middle cross beam 7 is preferably made of radiation absorbing material such as lead or other metals, preferably a tungsten alloy. A tungsten alloy has better radiation absorbing property than a lead alloy. However, a tungsten alloy is more expensive than a lead alloy. Only when necessary, a tungsten alloy is used such as in the middle cross beam 7 and the plates 2 where thickness of the pieces is preferably small. Since breast size varies significantly, the slidable plates 2 can squeeze the breasts appropriately so as to minimize the escaped radiation. The presence of the middle cross beam 7 and the two slidable plates 2 can minimize the radiation reaching the heart, lung, or other organs.

The sliding movement of the slidable plates 2 preferably utilizes a rack and pinion mechanism well known to the skilled in the arts. Referring to Fig. 1 b, the control

mechanism of the left slidable plate 2 of Fig. 1a is shown with the knob 3, the slidable plate 2, the pinion housing 6, a rack 9 with tooth, and a rod 10 whose end is a pinion (not shown in the drawing) inside the pinion housing 6. The rack 9 is fixed to the bottom of the slidable plate 2 and the pinion housing 6 is connected to the rear support 5. As the knob 3 is turn, the rod 10 (hence the pinion inside the pinion housing 6) turns. The torque from meshing of the rack 9 with the pinion can be converted to a linear force, causing the rack 9, hence the slidable plate 2, moves in a straight line.

The radiation shielding device of Fig. 1 doesn't need a bottom piece for cost saving reasons. However, a radiation shielding device comprising a bottom piece is also within the scope of the present invention.

Referring to Fig. 2, there is an illustration of an embodiment of a radiation shielding device of Fig. 1 further comprising a stationary door 11 and a slidable door 12. Both doors 11 and 12 are made of radiation absorbing material such as lead. The slidable door 12, also called a multileaf collimator, comprises multiple slidable pieces 13 interlocking each other as shown in the insert of Fig. 2. After the targeted breast has inserted into the compartment of the shielding wall 1 and after the tethered catheters or needles to the breast has been connected to the radiation delivery tube, the slidable door 12 can be closed to further reduce stray radiation. All slidable pieces can touch the stationary door 11 except for one to allow the tethered catheters or needles or the radiation delivery tube to pass.

Referring to Fig. 3, there is an illustration, in assembly view, of an embodiment of a prone breast treatment equipment comprising the radiation shielding device of Fig. 2, a middle section 14 with one closed breast hole (or cutout) 15 for the untargeted breast to pass and one open breast hole 16 for the targeted breast to pass, a upper section 17 comprising a breathing hole 18 for head support when the patient is in the prone position, and a lower section 19 for lower body support.

Referring to Fig. 4, there is an illustration, in prospective, of a prone breast treatment equipment of Fig. 3, after the radiation shielding device of Fig. 2, the upper section 17, the middle section 14, and the lower section 19 have been assembled. The two breast holes 15 and 16 plus the breathing hole 18 designs provides comfort to the patient while lying down in prone position. The presence of the closed breast hole 15 means the radiation- shielding device is intended to treat one breast at a time. After treating one breast, if the other breast also requires treatment, the upper section 17 and lower section 19 can be detached and switched with each other, and the patient can stand up, switch position by 180°, and play the other breast into the open breast hole 16. This design is more economical because only one side is shielded.

Referring to Fig. 5, there is an illustration, in prospective, of an embodiment of a prone breast treatment equipment comprising dual radiation shielding walls 1 and dual open breast holes 16. The design is the same as shown in Fig. 4 except that it has two radiation shielding walls 1 and two open breast holes 16. This is a symmetrical design with a mirror image along a middle line 20.

Referring to Fig. 6, there is an illustration, in prospective, of a radiation-shielding device with a slidable shielding plate 21 with a curved edge and a stationary shielding plate 22 with a curved edge where the breast makes the contact. In fact, shielding plates with curved edges or a multileaf collimator 23 are preferred in the present invention because they can seal the breast better, leaving less room for radiation to escape upward to heart, lung, or other unintended organs. To a skilled in the art it is obvious that other configurations of radiation shielding device are also possible and they are within the scope of the present invention. A non-limiting summary of possible configurations are shown in the following table:

A slidable shielding plate may mean a multileaf co limator.

Optional, the shielding devices of Figs. 1-6 are sitting on a raised platform with a well- known method.

For economic reasons the shielding devices of the present invention can be adopted to use together with prone breast boards currently being used in hospitals or clinics.

Referring to Fig. 7, there is an illustration, in prospective, of a prone breast treatment equipment with a one-piece-inclination-adjustable board design and the board 24 is in an upright position. The one-piece-inclination-adjustable board comprises a board 24, an apparatus base 30, two board supporting legs 31 , a board jacking device 32, a board stop 35, and a shielding wall piece. The board 24 comprises a lower section, a middle section 14, and an upper section. The lower section of the board 24 comprises a raised standing platform 25 connected to a pair of rods 26. The mechanism of the raised standing platform 25 is well known. One non-limiting example of the method of raising the standing platform 25 is to use one (or two) linear actuator (or a DART linear actuator, omitted in Fig. 7) located above the rods 26 fixed inside the body of the board 24. In this example, the raised standing platform 25 is fixed with the rods 26 and the rods 26 are actually the extending arms of the linear actuator 32. The linear actuator 32 can extend or retract the rods 26. A patient can stand on the raised standing platform 25 when the board 24 is upright and the patient (or a technician) can adjust the fitting of her breasts by controlling the position of the raised standing platform 25 by the controlling the linear actuator 35. The middle section 14 of the board 24 comprises two open breast hole cutouts 16, two multileaf collimators (shown later in Fig. 11 ), and a multileaf collimator support (shown later in Fig. 11 ). The upper section of the board 24 comprises a head rest 27, a pair of arm rests 28, and a hand grip 29. The board 24 is connected to the apparatus base 30 through two board supporting legs 31. The board 24 is able to move (or pivot) with the help of the board jacking linear actuator 32. The base of the board jacking linear actuator 32 is connected to the apparatus base 30. The extended arm of the board jacking linear actuator 32 is connected to the board 24. When the board jacking linear actuator 32 retracts, it is able to pull the board 24 to an upright position. When the board jacking linear actuator 32 extends, it is able to push the board 24 to a horizontal position. The shielding wall piece comprises a shielding wall support piece 33 fixed on the apparatus base 30, a shielding wall platform 34, and a pair of shielding walls 1 sitting back-to-back on top of the shielding wall platform 34. The shielding wall platform 34 is on top of the shielding wall supporting piece 33, and the two shielding walls 1 are on top of the shielding wall platform 34. Optionally the shielding wall supporting piece 33 is able to lift up or lower down the shielding wall platform 34. In one embodiment the shielding wall supporting piece 33 is a linear actuator. The board stop 35 is fixed at the end of the apparatus base 30. The apparatus base 30 is able to move due to the wheels 36.

The one-piece-inclination-adjustable board design in Fig. 7 is helpful because sometimes it is not easy for a patient to properly fit the breasts into the breast holes 16 due to the tether catheters or needles on the breasts and due to the physical condition of the patient.

Referring to Fig. 8, there is an illustration, in prospective, of the prone breast treatment equipment of Fig. 7 viewed at a different angle. The dotted line 37 indicates the rotation axis of the board 24.

Referring to Fig. 9, there is an illustration, in prospective, of the prone breast treatment equipment of Fig. 7 with the board 24 in an inclined position.

Referring to Fig. 10, there is an illustration, in prospective, of the prone breast treatment equipment of Fig. 7 with the board 24 in a horizontal position. The board jacking linear actuator 32 is able to push the board 24 until it is stopped and supported by the board stop 35. In this position, the breast hole cutouts 16 in the middle section 14 of the board 24 are able to lineup with the shielding walls 1 properly.

Referring to Fig. 11 , there is an illustration, in prospective, of a middle section of the board 24, with the top cover removed, comprising a pair of multileaf collimators 38 sandwiched between the removed top cover and a multileaf collimator support 39. The multileaf collimator 38 comprises radiation absorbing materials, preferably a tungsten alloy. After the breasts have been inserted into the positions, the leaves in the multileaf collimators 38 are able to slide and push by hands against the breast to minimize the escaping radiation. The advantage of the one-piece-inclination-adjustable board design of the present invention over the prior arts is that the technician is able to adjust the fitting of the multileaf collimators 38 when the board 24 is in an upright, inclined, or horizontal positions. Adjusting the multileaf collimators 38 in an upright or inclined position is easier than in a prone position because the technician can see the fitting better and doesn't have to bend his/her body. Therefore, one embodiment is a one-piece-inclination-adjustable board in Fig. 7. Another embodiment is a prone breast treatment equipment of Fig. 7.

Referring to Fig. 12, there is an illustration, in prospective, of the middle section of the board 24 of Fig. 11 viewed from below. There is a fastening unit 40 in each leaf on the multi-leaf collimator 38. The fastening unit 40 also serves as the handle when moved by hands and it is able to move through a trough cutout 41. It is able to tighten the leaf and fix it to the multileaf collimator support 39. Mechanism of fastening unit 40 is well known in the art. One non-limiting example of the fastening unit 40 is a bolt and nut fastener.

Referring to Fig. 13, there is an illustration, in prospective, of the middle section of the board 24 of Fig. 11 when the multileaf collimators 38 have been moved against the breasts (omitted in Fig. 11 ) to minimize the gap.

In Figs. 7 - 13, the multileaf collimators 38 are fixed in the middle section of the board 24. In another embodiment, the multileaf collimators 38 are separated from the board 24 and they are on the shielding walls 1. Such a design can reduce the weight of the board 24. That is, the shielding device comprising the multileaf collimators 38 and the shielding walls 1 are fixed on the apparatus base 30.

In another embodiment the shielding walls 1 are together with the multileaf collimators 38 in the board 24. That is, the shielding device comprising the multileaf collimators 38 and the shielding walls 1 are fixed on the board 24. In all embodiments, soft padding can be placed on any surfaces which contact the skins. The radiation absorbing material can have a coating or "skin" to prevent direct contact with people.

Claims

What is claimed is:

1. A radiation shielding device comprising at least one partially open shielding wall and at least one slidable shielding plate, wherein the shielding materials comprise a tungsten alloy, a lead alloy, or other radiation absorbing substances, wherein the at least one slidable shielding plate is on top of the at least one partially open shielding wall, wherein the contact edge of the shielding plate with a breast to be treated is either curved or flat, and wherein the at least one slidable shielding plate is capable of moving horizontally to minimize the open space directly above the partially open shielding wall to minimize the stray radiation emitted during a high-dose-rate brachytherapy for breast cancer treatment using a prone breast board, wherein the breast to be treated is placed inside the compartment of the radiation shielding device.

2. The radiation-shielding device of claim 1 comprises two slidable shielding plates and one partially open shielding wall.

3. The radiation-shielding device of claim 2 comprises one slidable shielding plate and one stationary shielding plate wherein the one slidable shielding plate and one stationary shielding plate are on top of the at least one partially open shielding wall.

4. The radiation shielding device of claim 1 comprises two sets of partially open shielding walls and two sets of slidable shielding plates, wherein the arrangement of the two sets of the partially open shielding walls and the two sets of the slidable shielding plates allows placement of both breasts into the compartments of the radiation shielding device for radiation treatment at the same time.

5. The radiation-shielding devices of claims 1 to 4 wherein each of the partially open shielding wall further comprises a slidable door capable of closing the opening of the partially open shielding wall while allowing catheters or needles tethered to the breast to be treated or a radiation delivery tube to pass during the radiation treatment.

6. The radiation shielding device of claim 1 wherein the partially open shielding wall is either a partially open round cylinder, a "U" shaped tube, or a 3-sided rectangular tube.

7. The radiation shielding device of claims 1 to 6 wherein the slidable shielding plate is a multileaf collimator.

8. A prone breast treatment equipment comprising a radiation shielding devices of claims 1 to 7, a prone breast board comprising a middle section, a upper section, and a lower section wherein the middle section comprises two breast hole cutouts for breast insertion wherein at least one of the breast hole cutouts is an open breast hole cutout, wherein the upper section comprises head rest or a breathing hole capable of supporting the head, and wherein the lower section comprises lower body supports; wherein the radiation shielding device is located directly below the two breast hole cutouts and wherein the compartments of the radiation shielding device and the breast hole cutouts of the middle section is able to line up for ease of breast insertion.

9. The prone breast treatment equipment of claim 8 wherein the upper board and lower board are detachable and switchable to allow treatment of the other breast after the first breast is treated.

10. A one-piece-inclination-adjustable board comprising a board, an apparatus base, two board supporting legs, a board jacking device, and a board stop;

wherein the board comprises a middle section, a upper section, and a lower section; wherein the middle section comprises two open breast hole cutouts for breast insertion, two multileaf collimators associated respectively with the two open breast hole cutouts, and a multileaf collimator support wherein the multileaf collimators are sandwiched between the top cover of the middle section and the multileaf collimator support;

wherein the upper section comprises head rest or a breathing hole capable of supporting the head; and

wherein the lower section comprises lower body supports comprising a raised standing platform;

wherein the board supporting legs, the board jacking device, and the board stop are fixed on the apparatus base; and

wherein the board hangs on the board supporting legs along an axis and the board is able to assume a upright position, an inclined position, and a horizontal position controlled by the board jacking device.

11. A prone breast treatment equipment comprising the one-piece-inclination- adjustable board of claim 10 and two partially open shielding walls fixed on the apparatus base wherein the two partially open shielding walls are able to align with the two open breast hole cutouts and the multi collimators for breast insertion when the board is in a horizontal position.

12. The prone breast treatment equipment of claim 11 wherein the two partially open shielding walls are fixed on the board instead of on the apparatus base and aligned with the two open breast hole cutouts and the multileaf collimators.

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13. The prone breast treatment equipment of claim 11 wherein the multileaf collimators are not in the one-piece-inclination-adjustable board but instead are with the two partially open shielding walls on the apparatus base.

14. The prone breast treatment equipment of claims 10 to 13 wherein the board jacking device is a linear actuator.

15. The prone breast treatment equipment of claims 11 and 14 wherein the partially open shielding walls are sitting on a raised shielding wall platform.

16. A method of shielding radiations during a high-dose-rate brachytherapy for breast cancer treatment comprising a patient standing on a raised platform on a one-piece- inclination-adjustable board of claims 1 1 to 15, adjusting the raised platform position and inserting the breasts to the breast hole cutouts on the board, lowering the board by a board jacking device to a horizontal position, a medical personnel fitting the slidable shielding plate(s) while the board is in a upright position or an inclined position and fitting the shielding walls against the breast to minimize the opening, and a medical personnel performing the high-dose-rate brachytherapy for breast cancer treatment.

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