Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M37/00—Other apparatus for introducing media into the body; Percutany, i.e. introducing medicines into the body by diffusion through the skin
  • A61M37/0069—Devices for implanting pellets, e.g. markers or solid medicaments
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B90/00—Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
  • A61B90/04—Protection of tissue around surgical sites against effects of non-mechanical surgery, e.g. laser surgery
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N5/00—Radiation therapy
  • A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy
  • A61N5/1001—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy using radiation sources introduced into or applied onto the body; brachytherapy
  • A61N5/1027—Interstitial radiation therapy
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B2017/00831—Material properties
  • A61B2017/00867—Material properties shape memory effect
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B90/00—Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
  • A61B90/04—Protection of tissue around surgical sites against effects of non-mechanical surgery, e.g. laser surgery
  • A61B2090/0409—Specification of type of protection measures
  • A61B2090/0427—Prevention of contact
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N5/00—Radiation therapy
  • A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy
  • A61N2005/1092—Details
  • A61N2005/1094—Shielding, protecting against radiation

Definitions

• the present invention relates to methods and apparatus for use in treating proliferative tissue disorders, and more particularly to methods and apparatus for protecting sensitive tissue during radiation therapy.
• Radiotherapy can be used to supplement surgical resection by targeting the residual tumor margin after resection, with the goal of reducing its size or stabilizing it. Radiation therapy can be administered through one of several methods, or a combination of methods, including external-beam radiation, stereotactic radiosurgery, and permanent or temporary brachytherapy.
• brachytherapy refers to radiation therapy delivered by a spatially confined radioactive material inserted into the body at or near a tumor or other proliferative tissue disease site. Owing to the proximity of the radiation source, brachytherapy offers the advantage of delivering a more localized dose to the target tissue region. Brachytherapy can be performed by implanting radiation sources directly into the tissue to be treated. Interstitial brachytherapy is traditionally carried out using radioactive seeds such as 125 I seeds. These seeds, however, produce inhomogeneous dose distributions.
• U.S. Patent No. 5,913,813 discloses a double-wall balloon catheter including a balloon, or distensible reservoir, that can pushing tissues away from close proximity to a radiation source. This allows the irradiated tissue to be in a region of shallow dose gradient and results in a reduced risk of "hot-spots" and radionecrosis.
• the amount of radiation desired by the physician is a certain minimum amount that is delivered to a region up to about two centimeters away from the margin of the excised tumor. It is desirable to keep the radiation that is delivered to the tissue in the target treatment region within a narrow absorbed dose range to prevent over-exposure to tissue at or near the radiation source, while still delivering the minimum prescribed dose at the maximum prescribed distance from the radiation source. It is also desirable, at least in some applications, to provide these advantages while tailoring the radiation dosage to avoid fully dosing sensitive tissue or to reduce the amount of radiation that escapes the patient's body.
• an instrument which can be used to deliver radiation from a radioactive source to target tissue within the human body with a desired intensity and at a predetermined distance from the radiation source without over-exposure of sensitive body tissues, such as skin or organ tissue for example, disposed proximate to the radiation.
• the present invention provides a radiation device with a positioning or spacing member, and methods of use for positioning a radiation source at a distance apart from sensitive tissue.
• the spacing member is useful in that it is effective to limit the amount of radiation that comes into contact with the adjacent tissue, and thereby protect sensitive tissue from receiving more radiation than it can tolerate safely, and/or protect against radiation exposure outside of the patient's body which may affect healthcare providers or others who might come close to the patient.
• the spacing member can have any shape and size, but is preferably adapted to provide a sufficient amount of space, hereinafter referred to as the desired spacing, between a radiation source within a brachytherapy device and adjacent tissue.
• the spacing member may space sensitive tissue from a radiation source within a brachytherapy device.
• the desired spacing is preferably adapted to prevent damage to healthy tissue cells, while allowing cancerous cells to be destroyed.
• the spacing member can be mated to or disposed in conjunction with a brachytherapy device, or alternatively, can be formed as an integral part of a brachytherapy device.
• the spacing member is formed from an expandable balloon member.
• the balloon member In the closed, deflated position, the balloon member is disposed or folded around an insertion member to allow the insertion member to be inserted through an opening, e.g. an introducer sheath, into a surgical excision site.
• the balloon member can be inflated to the open position to provide a predetermined amount of space between a radiation source and the tissue surrounding the surgical excision site.
• the necessary spacing is preferably equal to the height of the spacing member which is predeterminable - that is, the height can be fixed and predetermined, or the spacing member can be of a variable height that is selectable in use.
• the balloon member can have a preformed shape such that, when inflated, the balloon member is effective to provide the necessary spacing between the radiation device and the adjacent tissue.
• a brachytherapy device having an insertion member with proximal and distal ends, a first expandable balloon disposed on the distal end of the insertion member, and a spacing member disposed on the distal end of the insertion member proximal to the first expandable balloon.
• the expandable balloon is effective to receive a radiation source for treating target tissue surrounding a surgical excision site
• the spacing member is effective to position the expandable balloon at a distance apart from tissue surrounding an excision site.
• the spacing member is a second expandable balloon adapted for spacing tissue from the first expandable balloon.
• a brachytherapy device may include proximal and distal expandable balloons that are separately inflatable and adapted for different functions (i.e., spacing and containing a radiation source).
• a single expandable balloon includes both a spacing member and a radiation containing portion.
• a brachytherapy device can include an expandable surface member having multiple lobes. In use, one lobe can provide tissue spacing and space sensitive tissue from the other lobe which contains a radiation source.
• an asymmetric portion of an expandable surface member can act as the spacing member.
• a generally cylindrically shaped expandable surface member can include a outwardly positioned asymmetric spacing area which does not conform to the generally cylindrical shape.
• the asymmetric spacing area can provide increased spacing to sensitive tissue.
• the asymmetric area can space tissue from a radiation source positioned within the expandable surface member such that the spaced tissue receives a radiation dose less than an isodose received by tissue adjacent to the cylindrically shaped portion of the expandable surface member.
• the expandable surface member includes an asymmetric shape such that the asymmetric spacing area provides reduced spacing between tissue adjacent to the asymmetric spacing area and a radiation source position within the expandable surface member.
• One such exemplary asymmetric spacing area includes an inwardly positioned asymmetric spacing area that does not conform to the generally uniform shape of the expandable surface member.
• FIG. IA is perspective view of a spacing member according to one embodiment of the present invention
• FIG. IB is a perspective view of the spacing member of FIG. IA in an open, extended position
• FIG. 2A is a perspective view of an additional embodiment of a spacing member of the present invention formed from a shape memory material
• FIG. 2B is a perspective view of the spacing member of FIG. 2A partially inserted into an introducer sheath;
• FIG. 2C is a perspective view of the spacing member of FIG. 2A fully inserted through an introducer sheath and into an excision site;
• FIG. 2D is a perspective view of the spacing member of FIG. 2A positioned to space a brachytherapy device a distance apart from sensitive tissue proximate to the excision site;
• FIG. 3 A is a perspective view of another embodiment of a spacing member having an inflatable balloon member according to the present invention.
• FIG. 3B is a perspective view of the spacing member of FIG. 3 A illustrating the balloon member in a partially inflated position
• FIG. 3C is a perspective view of the spacing member of FIG. 3 A illustrating the balloon member in a fully inflated position
• FIG. 4A is a perspective view of yet another embodiment of a spacing member of the present invention having a spacing element disposed on a brachytherapy device;
• FIG. 4B illustrates the spacing member of FIG. 4A in an open, extended position
• FIG. 5A is a side view of another embodiment of a spacing member of the present invention having a spacing member formed integrally with a balloon member of a brachytherapy device;
• FIG. 5B illustrates the brachytherapy device and spacing member of FIG. 5 A in an inflated position
• FIG. 6A illustrates a side view of another embodiment of the present invention including a expandable balloon with spacing member
• FIG. 6B is a cut-away view of FIG. 6A along the line A-A;
• FIG. 7A illustrates a brachytherapy device disposed within a surgical excision site, and a spacing member according to one embodiment of the present invention prior to insertion into the surgical excision site;
• FIG. 7B illustrates the spacing member shown in FIG. 5A partially inserted into the surgical excision site
• FIG. 7C illustrates the spacing member of FIG. 5 A fully inserted into the surgical excision site
• FIG. 7D illustrates a brachytherapy device positioned at a distance apart from tissue disposed adjacent a surgical excision site by the spacing member of FIG. 5 A, which is shown extended into an open position;
• FIG. 8 illustrates a brachytherapy device disposed within a surgical excision site including a spacing member according to one embodiment of the present invention.
• the present invention relates to methods and apparatus for controlling the proximity of a radiotherapy source to sensitive tissue.
• radiation therapy makes use of the inherent difference in radiosensitivity between tumor cells and the adjacent normal tissues cells to destroy cancerous tissue while causing minimal disruption to surrounding normal tissues.
• the percentage of exposed cells that survive treatment decreases with first-order kinetics in proportion to increasing radiation dose. With increasing cell death comes increasing risk of necrosis or tissue death in healthy tissue that is treated with a high dose of radiation.
• the present invention provides a spacing member, and methods of use for positioning a radiotherapy source, such as a radiation source within a brachytherapy device, at a distance apart from sensitive tissue.
• the instrument is effective to limit the amount of radiation that comes into contact with the adjacent tissue, and thereby protect sensitive tissue from hotspots, and/or protect against radiation exposure outside of the patient's body which may affect healthcare providers or others who might come close to the patient.
• brachytherapy device as used herein is intended to refer to radiation therapy delivered into the body at or near a tumor or other proliferative tissue disease site.
• brachytherapy devices can use a variety of radiation sources, such as for example radioisotopes, miniature X-ray emitters (miniature X-ray tubes), and other radiation sources which can be positioned in conjunction with a brachytherapy device.
• radiation sources such as for example radioisotopes, miniature X-ray emitters (miniature X-ray tubes), and other radiation sources which can be positioned in conjunction with a brachytherapy device.
• exemplary radioisotopes can include beta- emitters, gamma-emitters, and X-ray emitters.
• the radioisotope is a beta-emitter, it may be selected from the group consisting of .sup.90 Y, .sup.188 Re, .sup.32 P, .sup.186 Re, .sup.106 Rh, and .sup.89 Sr; if the radioisotope is a gamma- emitter, it may be selected from the group consisting of .sup.60 Co, .sup.137 Cs, and .sup.192 Ir; or if the radioisotope is an X-ray emitter, it may be selected from the group consisting of .sup.103 Pd, .sup.109 Cd, .sup.145 Sm, .sup.149 Pm, .sup.169 Yb, and .sup.125 I.
• the spacing provided by the spacing member of the present invention is not limited to positioning and spacing brachytherapy devices.
• the disclosed spacing member may be used to position any type of radiation device or other medical device at a distance apart from tissue surrounding a surgical site.
• the spacing member according to the present invention can have a variety of shapes and sizes, and is preferably adapted to provide a sufficient amount of space, hereinafter referred to as the desired spacing, between the radiation source and sensitive tissue.
• the desired spacing is preferably adapted to prevent damage to healthy tissue cells, while allowing cancerous tissue to be destroyed.
• the spacing member can provide the desired spacing with a number of different embodiments.
• the spacing member can be a separate structure for disposing in conjunction with a brachytherapy device.
• the spacing member can be mated to, or formed with, a portion of the brachytherapy device.
• the spacing member can be mated with a catheter member or balloon member of a brachytherapy device, or in yet another embodiment, the spacing member can be formed integrally with the balloon member of a brachytherapy device.
• FIGS. IA and IB illustrate one embodiment of a device 10 including a spacing member 12 for use with a separate brachytherapy device.
• the device includes a spacing member 12 and an elongate insertion member 14 having a proximal end 16 and a distal end 18.
• the elongate member 14 can optionally include an inner lumen 20, and can be a catheter, introducer sheath, or similar device.
• the spacing member 12 can be disposed within the inner lumen 20, disposed on or mated to a portion of the distal end 18 of the elongate member 14, or alternatively, can be formed integrally with the elongate member 14.
• the spacing member 12 is substantially disk-shaped and includes a height h.
• the height h defines the desired spacing between the adjacent tissue and the brachytherapy device.
• the height h can be determined based on the amount of radiation being provided, and the distance between the radiation source and the tissue surrounding the excision site. While the spacing member can have any height h, preferably, the height is between about 1 and 5 millimeters, and more preferably is about 3 millimeters.
• FIG. IB also illustrates the spacing member 12 having a diameter d, which extends in a direction substantially perpendicular to the elongate member 14.
• the diameter d of the spacing member can vary, but is preferably determined based upon the intended use of the spacing member.
• the spacing member can be adapted to protect or shield a particular area of tissue, and therefore the diameter can be determined based upon the amount of surface area to be protected and the configuration of the brachytherapy device.
• the diameter d is between about 20 and 60 millimeters, and more preferably is about 40 millimeters.
• FIG. IB illustrates a substantially disk-shaped spacing member 12
• the spacing member 12 can have any shape, such as square, oval, rectangular, etc.
• diameter dimension d of the spacing member could represent any major dimension of a non-disk-shaped spacing member other than its height.
• the spacing member 12 can be movable between a closed position, shown in FIG. IA, wherein the spacing member 12 is substantially disposed around the elongate member 14, and an open or deployed position shown in FIG. IB, wherein the spacing member 12 is extended outward from the elongate member 14 in a direction substantially perpendicular to the elongate member 14. As shown in FIG. IA, the spacing member 12 is disposed upward toward the proximal end 16 of the elongate member 14 to prevent the spacing member 12 from opening during insertion through an introducer sheath (not shown).
• the spacing member 12 can also be formed from an elastic material which allows the spacing member 12 to wrap around the elongate member 14 in the closed position, and stretch outwardly from the elongate member 14 in the open position.
• the spacing member 12 can be disposed in a distal facing direction in the closed position, or can be disposed around or within the elongate member 14 in any manner that allows the device to be inserted through an introducer sheath and then extended into the open position.
• the spacing member can be formed integrally with the elongate member 14.
• FIG. 2 A illustrates a device 30 including spacing member 32 integrally formed on the distal end 18 of an elongate member 28, and being formed from a shape memory material.
• the shape memory material can be a metal shape memory material such as, for example, those disclosed in U.S. Patent No.
• the spacing member 32 is shown having an L-shape such that the spacing member 32 extends in a direction substantially perpendicular to the elongate member 28 in its pre-formed position.
• the introducer sheath 34 holds the spacing member 32 adjacent the elongate member 28 during insertion through the introducer sheath 34, as shown in FIG. 2B.
• the spacing member 32 can be inserted through an introducer sheath in a substantially straight, fully extended position (not shown). Once the spacing member is fully inserted through the introducer sheath, shown in FIG.
• the spacing member 32 resumes (due either to a release of steric constraints or a temperature increase from being placed inside the body) its preformed shape.
• the apparatus can then be retracted to position the spacing member 32 adjacent the tissue 36 proximate to the excision site 38. While an L-shaped spacing member 32 is illustrated in FIG. 2B, a person of ordinary skill in the art will recognize that various shapes could be used, including a circularly shaped spacing member formable in a plane that is perpendicular to a longitudinal axis of elongate member 28. Movement of the spacing member 32 according to the present invention between the open and closed positions can be accomplished by a variety of techniques.
• the apparatus can optionally include an actuating member (not shown), such as a wire, pulley assembly, lever, or similar device, effective to move the spacing member 32 to a position adjacent to the elongate member 28 to allow for insertion of the device through an introducer sheath, and/or to return the spacing member 32 to the open position once inserted.
• an actuating member such as a wire, pulley assembly, lever, or similar device, effective to move the spacing member 32 to a position adjacent to the elongate member 28 to allow for insertion of the device through an introducer sheath, and/or to return the spacing member 32 to the open position once inserted.
• actuating member such as a wire, pulley assembly, lever, or similar device
• FIGS. 3A-3C illustrate yet another embodiment of a separate spacing member according to the present invention having a spacing member 24 formed from an inflatable balloon member, and an elongate member 14' similar in purpose and construction to elongate member 14 discussed with respect to FIGS. 1 A-IB.
• the elongate member 14' includes an inner lumen 20' defining a pathway, and a port 26 in communication with the inner lumen 20' for providing air or liquid to inflate the spacing member 24.
• the elongate member 14' can optionally include an open distal end in communication with a second inner lumen (not shown) for receiving a brachytherapy device.
• the spacing member 24 is primarily sealed around the port 26 on the distal end 18 of the elongate member 14', and can include a predetermined shape in its expanded form, shown in FIG. 3C, such that, when inflated, the balloon has a height h which is adapted to provide the desired spacing between the brachytherapy device and the tissue adjacent the excision site.
• the spacing member 24 can have any shape, height h, as well as any diameter d, so long as the spacing member 24 is effective to provide the desired spacing between a brachytherapy device and the tissue adjacent the excision site.
• the height h and the diameter d of spacing member 24 can be the same or similar to the height h and the diameter d of spacing member 12 described with respect to FIG. IB.
• the height h of spacing member 24 can be selectable during treatment by inflating the balloon to a desired level so as to have the selected height.
• the spacing member can be mated to or formed integrally with a brachytherapy device.
• FIG. 4A illustrates a brachytherapy device 40 having an elongate member 42, a spacing member 44, and an expandable balloon member 46 for receiving a radiation source.
• the expandable balloon member 46 and the spacing member 44 are disposed on a distal end 18 of the elongate member 42, the spacing member 44 being disposed proximally to the balloon member 46.
• the elongate member 42 includes at least one inner lumen 20 in communication with a port 26 formed in the distal end 18 of the elongate member 42.
• the inner lumen 20 is effective to carry a radioactive source and/or an inflation source to the expandable balloon member 46 for inflating the balloon 46, and/or applying radiation to the excision site.
• the spacing member 44 is preferably movable between a closed position shown in FIG. 4A, and an open position shown in FIG. 4B. Movement can be accomplished by an actuating member (not shown), or alternatively, the spacing member 44 can be formed from a shape memory material to allow the spacing member 44 to be positioned properly once disposed within the excision site.
• the expandable balloon member 46 is effective to move the spacing member 44 to the open position, shown in FIG. 4B, upon expanding the balloon member 46.
• spacing member 24 is a separate balloon member such that first and second balloon member are separately inflatable.
• spacing member 44 preferably includes means for carrying separate inflation sources to spacing member 44 and expandable balloon 46.
• the spacing provided by spacing member 44 can be adjusted by varying the inflation pressure of the spacing member.
• Spacing member 44 is similar in purpose and construction to spacing members 12 and 24 described with respect to FIGS. 1A-1B, and 3A-3C. Thus, spacing member
• brachytherapy 44 can have any shape and size, can be positioned with respect the expandable balloon as needed (proximately, distally, etc.), can be formed integrally with elongate member 42, can be an expandable balloon member disposed on, around, or within elongate member 42, or can be any other type of structure effective for positioning a brachytherapy device at a distance apart from the surface of sensitive tissue proximate to the excision site.
• the spacing member is formed integrally with the expandable balloon member of a brachytherapy device as shown in FIGS. 5 A and 5B.
• the illustrated brachytherapy device 60 represents a typical brachytherapy device including an elongate member 62 and expandable balloon 64 positioned on the distal end thereof.
• the expandable balloon 64 includes a portion that acts as a spacing member 66.
• FIG. 5B shows the inflated expandable balloon with spacing member 66.
• the distal portion of the expandable balloon receives a radiation source, while spacing member 66 provides additional spacing between the radiation source and adjacent tissue.
• the spacing member can protect sensitive tissue adjacent to the cavity entrance.
• an inflated spacing member 66 can keep skin tissue around an opening to a resected cavity spaced from a radiation source within the brachytherapy device.
• the inflation medium used to inflate the expandable balloon and spacing member, can freely travel between the interior of the expandable balloon 64 and spacing member 66.
• a single inflation lumen can therefore inflate both expandable balloon 64 and spacing member 66.
• expandable balloon 64 and spacing member 66 are separately inflatable and the brachytherapy device 60 preferably includes separate inflation lumens for independent operation of the expandable balloon 64 and spacing member 66.
• a separately inflatable spacing member also allows the user to select different inflation mediums for the expandable balloon and the spacing member.
• expandable balloon 64 could be inflated with generally radiation transparent fluid, such as saline, while spacing member 66 could be inflated with a radiation blocking fluid, such as contrast fluid.
• a radiation blocking fluid such as contrast fluid.
• FIG. 6A illustrates a brachytherapy device with elongate member 62 and expandable balloon member 64 including spacing member 66 provided by an asymmetric bulge in the expandable balloon.
• the outwardly positioned asymmetric spacing area increases the distance between radiation source 72 and tissue adjacent to spacing member 66.
• FIG. 6B illustrates a cross section of the device of FIG. 6 A cut perpendicular to the axis of the elongate member along the line A-A.
• the cross section illustrates the nonconcentric circumference of the expandable balloon created by spacing member 66.
• expandable balloon 64 includes a generally uniform shape and cross section, with the exception of spacing member 66.
• the tissue spaced by the spacing member receives a radiation dose less than an isodose received by tissue adjacent to other portions of the expandable balloon.
• the expandable surface member can include an asymmetric shape such that the asymmetric spacing area provides reduced spacing between tissue adjacent to the asymmetric spacing area and a radiation source position within the expandable balloon.
• One such exemplary asymmetric spacing area includes an inwardly positioned asymmetric spacing area that does not conform to the generally uniform shape of the expandable surface member.
• the expandable balloon includes an area of increased (or decreased) thickness such that as the balloon expands, the area of increased thickness expands to a lesser (or greater) extent.
• the resulting balloon has an asymmetric shape that provides an area of increased spacing between a radiation source and adjacent tissue.
• area 68 in FIGS. 5 A and 5B could be an area of increased thickness such that as expandable balloon 64 expands, area 68 expands at a slower rate.
• the resulting expandable balloon includes proximal and distal lobes. With a radiation source placed in the distal lobe of the expandable balloon, the proximal lobe provides a spacing member such that tissue proximate to the expandable member is spaced from the radiation source.
• Variable thickness expandable balloon walls can be achieved in a number of ways. For example, during the construction of molded balloons (e.g., molded silicon balloons) the mold thickness can be varied. In other manufacturing processes, such as blow-molding of polyurethane, varying pressure and/or temperature differential on one area of the mold, using a shaped mold cavity, and/or selectively positioning the extrusion hole can create variations in the mold. Other variations in the primary manufacturing steps which create variations in the balloon wall thickness are also included within the scope of the invention.
• the wall thickness of brachytherapy balloons with variable wall thickness preferably remains above certain minimums to retain sufficient material strength and shape control. These preferred minimums will vary depending on the choice in construction material. As an example, the minimum thickness for a balloon constructed primarily from silicon is about 0.01 inches, and even more preferably not below 0.018 inches. Similarly, the variation in wall thickness necessary to produce variations in shape also depends on the construction material. For silicon balloons, the variation in wall thickness between adjacent portions of the expandable balloon is preferably in the range of about 0.001 to 0.04 inches, and even more preferably in the range of about 0.02 to 0.035 inches.
• balloon shape can be controlled with a constraining sleeve positioned around the balloon.
• the sleeve preferably controls the rate of expansion for a portion of the balloon such as the balloon inflates, the sleeve constrains the amount of expansion over a portion of the balloon.
• the balloon when expanded the balloon includes an unconstrained area having relatively more spacing from a radiation source.
• area 68 in FIG. 5A and 5B could be a constraining sleeve wrapped around expandable balloon 62.
• the expandable balloon can be constructed from a variety of materials including plastic, metal, composite materials, and the like.
• the materials can have a variety of properties depending on the use of the expandable balloon.
• the expandable balloon can be constructed from materials having minimal, or no, elasticity. Radiopaque materials, or radiopaque coating are also contemplated on all or a portion of the spacing member.
• Suitable radiopaque materials include, for example, barium, tungsten, bismuth, tantalum and tin.
• the spacing member of the invention can be used in the treatment of a variety of malignant tumors, and is especially useful in the treatment of brain and breast tumors.
• Surgery and radiation therapy are the standard treatments for malignant tumors. The goal of surgery is to remove as much of the tumor as possible without damaging vital tissue. The ability to remove the entire malignant tumor is limited by its tendency to infiltrate adjacent normal tissue. Partial removal reduces the amount of tumor to be treated by radiation therapy and, under some circumstances, such as with brain tumors, helps to relieve symptoms by reducing pressure on the brain.
• a common method for treating these and other malignancies begins by surgical resection of a tumor site to remove at least a portion of the cancerous tumor and create a resection cavity. Following tumor resection, but prior to closing the surgical site, the surgeon intra-operatively places a brachytherapy catheter apparatus into the tumor resection cavity.
• the brachytherapy catheter apparatus can be implanted or inserted into the tumor resection cavity up to several months after surgery is complete.
• the brachytherapy catheter can be loaded with a radiation source either during surgery or following recovery from surgery as medically appropriate.
• the radioactive source dwells in the catheter until the prescribed dose of radiotherapy is delivered, or the radiation source can be inserted for prescribed amounts of time on a daily or other scheduled basis until the prescribed dosage has been achieved.
• the radiation source is then retrieved and the catheter is removed.
• the radiation treatment may end upon removal of the brachytherapy apparatus, or the brachytherapy may be supplemented by further doses of radiation supplied externally.
• FIGS. 7A-7D illustrate a spacing member 10, as described with respect to FIGS. 1A-1B, in use with a brachytherapy device 50 to treat a breast cancer.
• spacer 10 and brachytherapy device 50 can then be deployed to treat remaining cancer cells while protecting sensitive tissue such as skin 36.
• Brachytherapy device 50 comprising generally an inflatable balloon 46 for housing a radiation source disposed on the distal end of catheter 56, is inserted (FIG. 7A) into a resection cavity 38 through surgical entry site 52, which may be the surgical approach through which the tumor was resected or an opening created specifically for deployment of brachytherapy device 50.
• Spacing member 10 can be inserted (FIG. 7B) into resection cavity 38 through a separate entry site 54 through introducer sheath 34.
• spacer 10 and brachytherapy device 50 can be inserted into resection cavity 38 in any order, and that spacer 10 can be inserted through either separate entry site 54 or through surgical entry site 52 depending on the configuration of spacer 10.
• spacing member 30 of FIGS. 2A-2D because of its configuration, could be inserted through either surgical entry site 52 or separate entry site 54. In the example illustrated in FIGS. 7A-7D, separate entry site 54 is used.
• spacing member 10 is folly inserted into resection cavity 38, spacing member 12 is moved to its open position, as shown in FIG. 7C. Spacing member 10 can then be retracted, or can be pushed against an outer surface of the resection cavity 38 upon inflation of the balloon member 46 of the brachytherapy device 50. Introducer sheath 34 can optionally be removed, leaving spacing member 10 abutting an outer surface of resection cavity 38, as shown in FIG. 7D, and maintaining the brachytherapy device at the desired spacing apart from skin 36.
• the spacing member must be inserted through the same entry site as the brachytherapy device as the spacer is connected to the brachytherapy device.
• FIG. 8 illustrates the brachytherapy device 60 of FIGS. 5 A and 5B positioned in resection cavity 38 and ready for inflation. Once inflated, spacing member 66 can provide spacing to sensitive tissue, particularly around surgical entry site 52.
• the brachytherapy devices of FIGS. 4A, 4B, 6 A, and 6B can be similarly inserted into resection cavity 38 and used in the same manner.

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• 2005
  • 2005-07-19 CA CA002574412A patent/CA2574412A1/en not_active Abandoned
  • 2005-07-19 WO PCT/US2005/025603 patent/WO2006014654A2/en active Application Filing
  • 2005-07-19 JP JP2007522658A patent/JP2008507344A/ja active Pending
  • 2005-07-19 AU AU2005269734A patent/AU2005269734B2/en not_active Ceased
  • 2005-07-19 EP EP05777223A patent/EP1781369A2/de not_active Withdrawn

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