1. Field of the Invention
The present disclosure relates to medical apparatus and methods. The present disclosure relates more particularly to apparatus and methods incorporating balloons that are positioned and inflated in one cavity of the body for the purpose of stabilizing an organ located outside that cavity for treatment of the organ. While the disclosure is primarily directed to apparatus and methods that help in the treatment of prostate and bladder cancer, the disclosure is not limited thereto.
2. State of the Art
Prostate cancer is a potentially lethal disease which affects nearly 200,000 men in the United States. External beam radiation therapy (EBRT) is a common method of treating prostate cancer. The goal of this treatment is to sterilize tumor cells and prevent the spread of disease beyond the prostatic capsule. For maximum efficacy, clinicians must deliver a lethal dose of radiation to the tumor while minimizing dosage to healthy surrounding tissue. This is often accomplished using fractionated treatments; i.e., a series of smaller doses delivered over a period of time. Unfortunately, the prostate, and tissue surrounding the prostate can move during and between fractionated treatments due to breathing, intestinal gas, patient movement due to discomfort or nervousness, the filling of the bladder, etc., resulting in less than maximum efficacy. As a result, it is not uncommon for a patient to be subjected to significant toxicity to normal tissue during radiation treatment. If the prostate could be immobilized, and/or if the surrounding tissue can be moved out of the treatment area, a more ideal radiation dose can be prescribed.
There are many known devices that are ostensibly adapted to aid in the positioning of the prostate for the purposes of maximizing radiation therapy. Medical balloons, such as the Foley catheter, have been expanded in the rectum in order to compress the prostate and thereby prevent prostate motion. These devices do improve treatment outcomes. At the same time, they are uncomfortable, do not necessarily permit ideal dose characteristics, and are often inconvenient for clinician usage. As a result, they have seen limited usage.
This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.
A medical apparatus includes a catheter having an inflatable balloon at its distal end. The balloon defines at least two spaced larger diameter areas defining a valley therebetween and is adapted to be inserted in a non-inflated condition into a cavity of the human body such as the rectum, and when inflated, is adapted to cradle an organ such as the prostate located in a different body cavity. The balloon is also rotationally non-directional (symmetric) about an axis defined by the catheter so that positioning issues are limited to axial positioning rather than rotational positioning. Because of the valley in the balloon, when the balloon is inflated, only a limited portion of the rectum is necessarily pushed into contact with the prostate, and thus, the radiation toxicity to the rectum is limited. The catheter includes at least one lumen adapted for use in inflating the balloon.
In one embodiment, the catheter defines a hole distal the balloon and is provided with an additional lumen for venting fluid from distal the balloon to proximal the balloon via the hole and lumen. In one embodiment, the catheter is provided with an additional lumen adapted to receive a stiffening rod that may be used to cause the catheter to assume a desired shape (e.g., an arc) along its length.
In one embodiment, a stop element may be placed on the catheter to prevent movement of the catheter after positioning. In one embodiment where the catheter is adapted to be inserted through the rectum, the stop element is an external ring that may be moved up against the rectal opening, thereby preventing the catheter from inadvertent distal movement. In another embodiment where the catheter is adapted to be inserted through the rectum, the stop element is an internal anal stop element that is adapted to be located proximal the balloon and to prevent inadvertent proximal movement of the catheter. In one embodiment, the internal stop element is another balloon that may be inflated separately from the balloon having at least two spaced larger diameter areas defining a valley therebetween. In another embodiment, the internal stop element is a more proximal large diameter area of the balloon having at least two spaced larger diameter areas defining a valley therebetween.
In one embodiment, the balloon having at least two spaced larger diameter areas defining a valley therebetween is a single shaped plastic balloon capable of being pressurized to a pressure of at least 6 psi.
In one embodiment, the balloon having at least two spaced larger diameter areas defining a valley therebetween has the outer diameter at the larger diameter areas being between 20% and 40% larger than the outer diameter of the valley.
In one embodiment, the balloon when inflated will not substantially deform when contacting an organ through a cavity wall. In one embodiment, a balloon has a hardness of at least 80A Durometer.
In one embodiment, the balloon having at least two spaced larger diameter areas defining a valley therebetween is a single balloon having a form constricting element arranged between the ends of the balloon so that, when inflated, the balloon forms two crests about the constricting element.
In one embodiment, the balloon having at least two spaced larger diameter areas defining a valley therebetween is a single balloon forming three or more crests and valleys between adjacent crests. With multiple valleys, tissue defining the cavity in which the balloon is located has an opportunity to rest in the valleys, thus reducing radiation toxicity to that tissue.
In one aspect, bladder cancer in a woman may be treated using a catheter with a balloon as previously described by inserting the catheter into the vagina and inflating the balloon, thereby pushing the bladder away from the rectum or vice versa.
Additional aspects and advantages of the embodiments will be appreciated with reference to the detailed description taken in conjunction with the drawings.
A first embodiment of a medical apparatus 10 is seen in
In the first embodiment, the balloon 30 is generally “peanut-shaped” with two spaced larger diameter areas 32a, 32b defining a valley 34 therebetween. In one embodiment, the diameter of the larger diameter areas 32a, 32b is approximately 4.8 cm, and diameter of the valley 34 is approximately 3.7 cm, and the length of the balloon is approximately 10 cm with a peak-to-peak distance of approximately 6 cm, and the balloon is generally adapted to cradle a prostate (not shown). The distal end of the balloon 30 is located approximately 3 cm from the end of the catheter 20. As seen by comparing
While multi-lumen catheter 20 is shown having two lumens, the catheter may have more than two lumens. A second embodiment of an apparatus 110 is seen in
Turning to
Turning now to
An apparatus 610 similar to apparatus 10 but with an internal stop element 680 is seen in
In one embodiment, the diameter of the spaced larger diameter areas is between substantially 4 and 10 cm, the diameter of the valley is between substantially 1 and 6 cm smaller than the diameter of the spaced larger areas, and the length of the balloon is between substantially 8 and 16 cm, wherein the term “substantially” is defined as ±10%.
In embodiments, the diameters of the spaced larger diameter areas of the balloon are different. In one embodiment, the more distal larger diameter balloon area has a larger diameter than the more proximal larger diameter balloon area. In one aspect a larger diameter distal balloon area can push distal seminal vesicles further from a radiation site, while a relatively smaller larger diameter proximal balloon area can reduce the urination urge of a patient. In some embodiments, both larger diameter balloon areas are between 20% and 40% larger in outer diameter than the outer diameter of the valley defined between the larger diameter areas.
In one aspect, aspects of the described embodiments may be used in conjunction with each other. Thus, by way of example only and not by way of limitation, different embodiments of the balloons 30, 130, 230, 330, 430, 530, 630 may be used in conjunction with different catheters. Similarly, markings on catheter 20 can be used in conjunction with any of catheters 120, 220, 320, 420, 520, 620. Internal and/or external stop elements 570, 680 may be used in conjunction with any of the described balloons and any of the catheters.
In one embodiment, apparatus 10, 110, 510, 610 using any of balloons 30, 130, 230, 330, 430, 530, 630 is used as follows. With respect to EBRT, before radiation treatment begins a planning or simulation session is required to pinpoint the tumor and determine the treatment sequence. A support mold is created that supports the back, pelvis and thighs of the patient to ensure accurate positioning over the course of radiation treatments. A tomographic (CT) scan of the pelvis is taken while the patient is supported by the mold and the CT scan is used to generated a 3D image of the pelvic anatomy including the prostate, bladder, rectum and pelvic bones. An x-ray simulator is then used to provide a picture of the tumor site and help determine how the radiation will be directed to it. The beams of the simulator are positioned to deliver the appropriate dose of radiation to the prostate while sparing surrounding healthy tissues and structures. Beam positioning is then verified using fluoroscopy. Using the x-rays as a guide, a radiation therapist may make marks on the treatment area on the patient's skin that are to be used as a guide during treatment. Treatment is accomplished over a period of weeks; usually five days a week for six to eight weeks. Each procedure during the treatment period lasts minutes at a time. The procedure involves positioning the patient in the mold on an x-ray table according to the map on the patient's skin and the information obtained from the simulation. Where a linear accelerator is used for treatment, the linear accelerator is activated and moves in a circular fashion around the tumor area of the patient. The radiation is applied over a period of minutes.
The apparatus 10, 110, 510, 610 using any of balloons 30, 130, 230, 330, 430, 530, 630 may be used during treatment, during x-ray simulation, and during CT scanning, if desired. In each situation, an introducer or shaft 150 is optionally shaped as desired, and optionally inserted into a lumen of the apparatus 10, 110, 510, 610 (e.g., into vent port lumen 20b via catheter portion 26b and vent port 29, or into introducer lumen 120c). The apparatus with the optionally inserted shaft 150 (and with the balloon in a deflated condition) is inserted through the rectal opening of the patient and moved to a location adjacent the prostate. In the case of use during treatment, the distance (extent of movement) of the apparatus into the rectum may have been predetermined either by previous experience during x-ray simulation and/or CT scanning, or by having taken measurements from the CT scan, and the markings (e.g., markings 31) may be used to establish positioning. Once the catheter and balloon are properly positioned axially, the introducer or shaft 150, if utilized, may be removed. Because the balloon is symmetric about the longitudinal axis of the catheter, there is no need to rotationally position the catheter and balloon. The balloon may then be inflated by injecting air or other fluid through the inflation port of the apparatus such that the balloon inflates and cradles the prostate, even though the rectum wall is located between the balloon and the prostate. The cradling of the prostate advantageously prevents movement of the prostate during a procedure. Also, because the balloon is provided with one or more valleys when the balloon is inflated, only a limited portion of the rectum is necessarily pushed into contact with the prostate, and thus, radiation toxicity to the rectum is limited during application of radiation. Prior to or after inflation of the balloon, an external stop 570, if available, may be moved into position against the outside of the rectal opening to prevent inadvertent distal movement of the apparatus. In addition, prior to, during, or after inflation of the balloon, an internal stop 580, if available, may be inflated inside the rectum to prevent inadvertent proximal movement of the apparatus. While the balloon is inflated, if desired, in some embodiments, negative pressure may be applied at the vent port so that digestive waste in the rectum that is distal the balloon may pass into the vent hole, through the catheter and out the vent port. After radiation is completed, the balloon (and internal stop 580, if any) is deflated via the inflation port, and the catheter may be removed from the patient by pulling on it proximally.
In one aspect, bladder cancer in a woman may be treated using a catheter with an apparatus as previously described by inserting the catheter of the apparatus into the vagina and inflating the balloon, thereby pushing the bladder away from the rectum or vice versa.
In one aspect, one or more diagnostic elements may be provided on the balloon of the apparatus. In one embodiment, one or more dosimeters are placed on the surface of the balloon. Where multiple dosimeters are utilized, the dosimeters may be arranged in an array or otherwise. The dosimeters may be spaced axially and circumferentially and may be located on the inside or outside surface of the balloon. In one embodiment the dosimeters are film dosimeters with films that increase in optical density in response to incident radiation. In another embodiment the one or more diagnostic elements include one or more pressure sensors. In one embodiment, multiple diagnostic elements of different types are utilized together. By way of example only, one or more dosimeters and one or more pressure sensors may be placed on the balloon of the apparatus.
In another aspect, one or more therapeutic elements may be provided on the balloon of the apparatus. In one embodiment, the balloon of the apparatus is provided with an agent such as a drug that may be beneficial to the rectal mucosa. By way of example only, the drug may be a poly (ADP-ribose) polymerase. The drug may be placed on the outer wall of the balloon and may elute when the balloon is pushed with force against the wall of the colon. Also by way of example only, the drug may be an oxygenation-decreasing drug that protects the healthy rectal mucosa.
There have been described and illustrated herein several embodiments of an apparatus and a method for treatment of an organ. While particular embodiments have been described, it is not intended that the teachings be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise. Thus, while particular embodiments of balloons with particular sizes and materials have been disclosed, it will be appreciated that other embodiments of balloons with other sizes and materials may be used as well. Also, while single balloons that are shaped to cradle the prostate have been disclosed, it will be appreciated that the single balloons can be replaced with multiple balloons that are arranged to simulate the single balloons. The multiple balloons can be individually inflatable and deflatable. It will therefore be appreciated by those skilled in the art that yet other modifications could be made to the provided without deviating from its spirit and scope of the claims.
This application claims priority from U.S. provisional Ser. No. 61/719,435 filed Oct. 28, 2012 and entitled “Apparatus for Improved Prostate Radiation Therapy” which is hereby incorporated by reference herein in its entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/US13/66829 | 10/25/2013 | WO | 00 |
Number | Date | Country | |
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61719435 | Oct 2012 | US |