Patent Application
20100010287
This invention relates generally to the fields of medical treatment devices and methods of use. In particular, the invention relates to devices and methods for irradiating tissue surrounding a body cavity, such as a site from which cancerous, pre-cancerous, or other tissue has been removed.
In diagnosing and treating certain medical conditions, it is often desirable to perform a biopsy, in which a specimen or sample of tissue is removed for pathological examination, tests and analysis. A biopsy typically results in a biopsy cavity occupying the space formerly occupied by the tissue that was removed. As is known, obtaining a tissue sample by biopsy and the subsequent examination are typically employed in the diagnosis of cancers and other malignant tumors, or to confirm that a suspected lesion or tumor is not malignant. Treatment of cancers identified by biopsy may include subsequent removal of tissue surrounding the biopsy site, leaving an enlarged cavity in the patient's body. Cancerous tissue is often treated by application of radiation, by chemotherapy, or by thermal treatment (e.g., local heating, cryogenic therapy, and other treatments to heat, cool, or freeze tissue).
Cancer treatment may be directed to a natural cavity, or to a cavity in a patient's body from which tissue has been removed, typically following removal of cancerous tissue during a biopsy or surgical procedure. For example, U.S. Pat. No. 6,923,754, U.S. patent application Ser. No. 10/849,410, U.S. patent application Ser. No. 11/593,784 and U.S. patent application Ser. No. 11/716,758, the disclosures of which are all hereby incorporated by reference in their entireties, describe devices for implantation into a cavity resulting from the removal of cancerous tissue which can be used to deliver radiation to surrounding tissue. One form of radiation treatment used to treat cancer near a body cavity remaining following removal of tissue is “brachytherapy” in which a source of radiation is placed near to the site to be treated.
Lubock above describes implantable devices for treating tissue surrounding a cavity left by surgical removal of cancerous or other tissue that includes an inflatable balloon constructed for placement in the cavity. Such devices may be used to apply one or more of radiation therapy, chemotherapy, and thermal therapy to the tissue surrounding the cavity from which the tissue was removed. The delivery lumen of the device may receive a solid or a liquid radiation source. Radiation treatment is applied to tissue adjacent the balloon of the device by placing radioactive material such as radioactive “seeds” in a delivery lumen. Such treatments may be repeated if desired.
U.S. patent application Ser. No. 11/593,784, filed on Nov. 6, 2006, entitled “Asymmetrical Irradiation Device for A Body Cavity” describes a brachytherapy device having a plurality of individual tubular members which extend away from a central longitudinal axis and which are surrounded by an expandable member or balloon. A commercial embodiment of such a device, the Contura™ Multi-Lumen Radiation Balloon (MLB) Catheter, is now being sold by the present assignee SenoRx Inc.
Tissue cavities resulting from biopsy or other surgical procedures such as lumpectomy typically are not always uniform or regular in their sizes and shapes, so that radiation treatment often result in differences in dosages applied to different regions of surrounding tissue, including “hot spots” and regions of relatively low dosage. However, by conforming the tissue lining the cavity about an inflated member, such as a balloon, a more uniform or controlled radiation can be applied to the tissue.
However, making a robust, inflatable balloon which has a predictable inflated size and shape can be problematic, particularly with a balloon size suitable for breast biopsy/lumpectomy cavities which range from about 0.5 to about 4 inches in maximum diameter, and are typically about 2 inches.
The present invention is directed to a brachytherapy catheter having an elongated shaft, a distal shaft section, one or more toroidal shaped expandable. members surrounding a length of the distal shaft section and at least one radiation guide member having an inner guide or lumen for locating a radiation source along the length of the distal shaft section. Preferably, the one or more toroidal balloons are shorter than the length of the distal shaft section. The one or more balloons are secured to the balloon catheter, preferably to one or more of the radiation guide members or to the distal tip of the catheter. The connections may be stiff or flexible but the assembly must be suitable for advancement through a patient's tissue with minimal difficulty.
The present invention provides devices and methods for treatment of a patient's body cavity. Specifically, devices and methods having features of the invention may used to deliver radiation into a biopsy site or into a cavity left after removal of cancerous tissue from the patient's body.
The plurality of tubular guide members 13 and 17 may extend proximally to an adapter (not shown) on the proximal end of the catheter. Alternatively, the catheter 10 may have a proximal shaft section (not shown) having a plurality of lumens which are in fluid communication with the lumens in the tubular guides located in the distal shaft section and which are configured to receive one or more radiation sources and guide the sources to the inner lumens 16 and 18 of the tubular guide members 12 and 16. These features are shown in copending applications Ser. No. 11/593,784 and Ser. No. 11/716,758.
The tubular members 12 and 16 may have a support element shown in copending applications (Ser. No. 11/593,784 and Ser. No. 11/716,758), which would extend along length of the treatment location and have compartments which are designed to receive and support the tubular radiation guide members.
All of the tubular guide members which extend through the treatment location would not necessarily be used in a particular irradiation procedure, but they would be available for use by the physician if needed, e.g. when the balloon 12 of the radiation catheter 10 is not in a desired position and rotation of the catheter is not appropriate or desirable.
The radiation source for the brachytherapy device is preferably a radiation seed on the distal end of rod, but the radiation source may be a solid or liquid radiation source. Solid radionuclides suitable for use with a device 10 embodying features of the present invention are currently generally available as brachytherapy radiation sources available from Med-Tec, Orange City, Iowa. Suitable liquid radiation sources include, for example, a liquid containing a radioactive iodine isotope (e.g., I125 or I131), a slurry of a solid isotope, for example, 198Au or 169Yb, or a gel containing a radioactive isotope. The radiation source is usually loaded into the catheter device 10 after placement into a body cavity or other site of a patient.
The various device components can be provided, at least in part, with a lubricious coating, such as a hydrophilic material. The lubricious coating preferably is applied to the elongate shaft or tubular members and to the toroidal balloon, to reduce sticking and friction during insertion and withdrawal of the device 10. Hydrophilic coatings such as those provided by AST, Surmodics, TUA Systems, Hydromer, or STS Biopolymers are suitable. The surfaces of the device 10 may also include an antimicrobial coating that covers all or a portion of the device 10 to minimize the risk of introducing of an infection during extended treatments. The antimicrobial coating preferably is comprised of silver ions impregnated into a hydrophilic carrier. Alternatively the silver ions are implanted onto the surface of the device 10 by ion beam deposition. The antimicrobial coating may also be an antiseptic or disinfectant such as chlorhexadiene, benzyl chloride or other suitable biocompatible antimicrobial materials impregnated into hydrophilic coatings. Antimicrobial coatings such as those provided by Spire, AST, Algon, Surfacine, Ion Fusion, or Bacterin International would be suitable. Alternatively a cuff member covered with the antimicrobial coating may be provided on the elongated shaft of the delivery device 10 at the point where the device 10 enters the patient's skin.
The balloon 11 may also be filled with radiopaque inflation material to facilitate detection during CT, X-ray or fluoroscopic imaging. Such imaging allows the physician or other staff to detect the size and shape of the balloon and whether the balloon is properly located at the desired location. Alternatively, the exterior surface of an inner layer of the balloon may be coated at least in part with radiopaque material.
The device 10 may be used to treat a body cavity of a patient, e.g. a biopsy or lumpectomy site within a patient's breast, in the manner described in the previously referred to co-pending applications. Usually the proximal end of the catheter device extends out of the patient during the procedure when the balloon is inflated.
Radiation balloon catheters for breast implantation generally are about 6 to about 12 inches (15.2-30.5 cm) in length, typically about 10.6 inch (27 cm). The shaft diameter is about 0.1 to about 0.5 inch (2.5-12.7 mm), preferably about 0.2 to about 0.4 inch (5.1-10.2 mm), typically 0.32 inch (8 mm). The individual radiation lumens are about 0.02 to about 0.15 inch (0.5-3.8 mm), preferably about 0.04 to about 0.1 inch (1-1.5 mm). The balloons are designed for inflated configurations about 0.5 to about 4 inches (1.3-10.2 cm), typically about 1 to about 3 inches (2.5-7.5 cm) in transverse dimensions, e.g. outer diameters.
While particular forms of the invention have been illustrated and described herein, it will be apparent that various modifications and improvements can be made to the invention. To the extent not previously described, the various elements of the catheter device may be made from conventional materials used in similar devices. Moreover, individual features of embodiments of the invention may be shown in some drawings and not in others, but those skilled in the art will recognize that individual features of one embodiment of the invention can be combined with any or all the features of another embodiment. Accordingly, it is not intended that the invention be limited to the specific embodiments illustrated. All patents and all patent applications referred to above are hereby incorporated by reference in their entirety. Further details of brachytherapy catheters can be found in the patents and applications incorporated herein by reference.
Terms such as “element”, “member”, “component”, “device”, “means”, “portion”, “section”, “steps” and words of similar import when used herein shall not be construed as invoking the provisions of 35 U.S.C §112(6) unless the following claims expressly use the terms “means for” or “step for” followed by a particular function without reference to a specific structure or a specific action.
This application is related to provisional application Ser. No. 61/134,337, filed on Jul. 9, 2008, which is incorporated herein in its entirety and which is relied upon for priority.
| Number | Date | Country | |
|---|---|---|---|
| 61134337 | Jul 2008 | US |
