111111
`
`1111111111111111111111111111111111111111111111111111111111111111111111111111
`US 20080177179Al
`
`(19) United States
`c12) Patent Application Publication
`Stubbs et al.
`
`(10) Pub. No.: US 2008/0177179 A1
`Jul. 24, 2008
`(43) Pub. Date:
`
`(54) TARGET TISSUE LOCATOR FOR IMAGE
`GUIDED RADIOTHERAPY
`
`(22) Filed:
`
`Dec. 18, 2007
`
`(75)
`
`Inventors:
`
`James Stubbs, Palo Alto, CA (US);
`Gregory K. Edmundson, Rough &
`Ready, CA (US); Srihari
`Yamanoor, Sunnyvale, CA (US);
`Russel M. Sampson, Palo Alto, CA
`(US)
`
`Correspondence Address:
`CYTYC CORPORATION
`250 CAMPUS DRIVE
`MARLBOROUGH, MA 01752
`
`(73) Assignee:
`
`Cytyc Corporation, Marlborough,
`MA(US)
`
`(21) Appl. No.:
`
`11/959,106
`
`Related U.S. Application Data
`
`(60) Provisional application No. 60/875,776, filed on Dec.
`19,2006.
`
`Publication Classification
`
`(51)
`
`Int. Cl.
`A61B 5100
`A61B 18118
`
`(2006.01)
`(2006.01)
`
`(52) U.S. Cl. ........................................... 600/431; 607/88
`
`(57)
`
`ABSTRACT
`
`The present invention relates to different methods of delin(cid:173)
`eating target tissue from non-target tissue using differences in
`radiographic properties of a medical device.
`
`Focal Exhibit 1013 Page 1
`
`

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`US 2008/0177179 A1
`
`Jul. 24, 2008
`
`1
`
`TARGET TISSUE LOCATOR FOR IMAGE
`GUIDED RADIOTHERAPY
`
`FIELD OF THE INVENTION
`
`[0001] A method for treating tissue surrounding a cavity
`that is subject to a proliferative tissue disorder is provided.
`The method includes a tissue fixation device to position the
`tissue surrounding a resection cavity in a predetermined
`geometry. The tissue fixation device contains a negative con(cid:173)
`trast agent for localizing target tissue by visualizing the nega(cid:173)
`tive contrast agent in three dimensions. Methods of delineat(cid:173)
`ing target tissue from non-target tissue using differences in
`radiographic properties of a device are also presented.
`
`A BACKGROUND OF THE INVENTION
`
`[0002] The invention relates generally to systems and
`methods for use in treating proliferative tissue disorders, and
`more particularly to systems and methods for the treatment of
`such disorders in the breast by positioning tissue and applying
`radiation.
`[0003] Malignant tumors are often treated by surgical
`resection of the tumor to remove as much of the tumor as
`possible. Infiltration of the tumor cells into normal tissue
`surrounding the tumor, however, can limit the therapeutic
`value of surgical resection because the infiltration can be
`difficult or impossible to treat surgically. Radiation therapy
`can be used to supplement surgical resection by targeting the
`residual tumor margin after resection, with the goal of reduc(cid:173)
`ing its size or stabilizing it. Radiation therapy can be admin(cid:173)
`istered through one of several methods, or a combination of
`methods, including permanent or temporary interstitial
`brachytherapy, and external-beam radiation.
`[0004] 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.
`[0005] For example, brachytherapy is performed by
`implanting radiation sources directly into the tissue to be
`treated. Brachytherapy is most appropriate where 1) malig(cid:173)
`nant tumor regrowth occurs locally, within 2 or 3 em of the
`original boundary of the primary tumor site; 2) radiation
`therapy is a proven treatment for controlling the growth of the
`malignant tumor; and 3) there is a radiation dose-response
`relationship for the malignant tumor, but the dose that can be
`given safely with conventional external beam radiotherapy is
`limited by the tolerance of normal tissue. In brachytherapy,
`radiation doses are highest in close proximity to the radio(cid:173)
`therapeutic source, providing a high tumor dose while sparing
`surrounding normal tissue. Interstitial brachytherapy is use(cid:173)
`ful for treating malignant brain and breast tumors, among
`others.
`[0006] Williams U.S. Pat. No. 5,429,582, entitled "Tumor
`Treatment," describes a Brachytherapy method and apparatus
`for treating tissue surrounding a surgically excised tumor
`with radioactive emissions to kill any cancer cells that may be
`present in the tissue surrounding the excised tumor. In order
`to implement the radioactive emissions, Williams provides a
`catheter having an inflatable balloon at its distal end that
`defines a distensible reservoir. Following surgical removal of
`a tumor, the surgeon introduces the balloon catheter into the
`surgically created pocket left following removal of the tumor.
`
`The balloon is then inflated by injecting a fluid having one or
`more radionuclides into the distensible reservoir via a lumen
`in the catheter.
`[0007] While brachytherapy procedures have successfully
`treated cancerous tissue, alternative radiation treatments are
`sometimes preferable, including radiation therapies which
`are delivered from a source external to the patient. For
`example, External Beam Radiation Therapy involves direct(cid:173)
`ing a "beam" of radiation from outside the patient's body,
`focused on the target tissue within a patient's body. The
`procedure is painless and often compared to the experience of
`having an x-ray.
`[0008] As with any radiation therapy, the goal is to deliver
`a prescribed dose of radiation to the target tissue while mini(cid:173)
`mizing damage to healthy tissue. More recent advances in
`radiation therapy such as Three-Dimensional Conformal
`Radiation Therapy (3DCRT) and Intensity Modulated Radia(cid:173)
`tion Therapy (IMRT) have increased the precision of external
`radiation therapy with sophisticated shaping and directing of
`therapeutic radiation beams. In addition, imaging techniques
`allow delineation of a more complex planning target volume
`("PTV", PTV refers to the mass of tissue which includes both
`the residual malignancy as well as a margin of surrounding
`healthy tissue). These imaging procedures use cross-sec(cid:173)
`tional imaging modalities including computed tomography
`(CT), magnetic resonance imaging (MRI), positron emission
`tomography (PET), single photon emission computed tomog(cid:173)
`raphy (SPECT) and portal imaging to visualize target tissue.
`Treatment planning software combines the anatomical details
`from the imaging procedures and a PTV outlined by the
`physician, to optimize the number, size and shape of the
`radiotherapy beams used to treat the patient. The goal of the
`treatment plan is to deliver a conformal radiation dose to the
`PTV and minimize the radiation delivered to adjacent normal
`tissue outside the PTV.
`In use, 3DCRT provides radiation beams shaped to
`[0009]
`"conform" to a target tissue volume, and with the ability to
`visualize and to arrange the radiation therapy beams, physi(cid:173)
`cians can maximize coverage of the target tissue and mini(cid:173)
`mize exposure to normal tissue. IMRT similarly conforms
`radiation beams to the size, shape and location of the target
`tissue by using hundreds to thousands of small, modulated
`radiation beams, striking the target tissue with varying inten(cid:173)
`sities. The multitude of beams treats the target tissue and
`minimizes damage to healthy tissue. Yet, even the most
`advanced procedures require the patient and the target tissue
`to be properly positioned, and in some cases immobilized.
`Unfortunately, the irregular surface of a cavity created by the
`resection of tissue can make it difficult for the imaging tech(cid:173)
`niques to determine the exact location of the target tissue, and
`even with the opportunity to completely map the target area,
`the unsupported tissue surrounding the resected cavity may
`shift during the procedure or between imaging and treatment,
`particularly where the treatment regimen involves radiation
`doses provided over the course of several days or weeks.
`[0010] As a result, there is still a need for additional meth(cid:173)
`ods for delivering radiation from an external radiation source
`to tissue adjacent to a resected tissue cavity with a desired
`accuracy and without over-exposure of surrounding tissue.
`External beam radiation therapy involves directing or focus(cid:173)
`ing a "beam" of radiation from the outside of a patient's body
`to an area of target tissue within the patient's body. The
`procedure is a non-invasive and relatively painless medical
`procedure which is used to treat abnormal or cancerous tissue
`
`Focal Exhibit 1013 Page 2
`
`

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`US 2008/0177179 A1
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`Jul. 24, 2008
`
`2
`
`in a patient. External radiation therapies rely on precise imag(cid:173)
`ing and/or targeting techniques to locate tissues of interest for
`treatment. Patient positioning is often critical to the success of
`radiation therapy and great measures are often taken to ensure
`that patients are correctly positioned and immobilized. Even
`with the patient immobilized, internal movement of a
`patient's tissues as well as incorrect positioning of a patient's
`body can result in the damaging of normal healthy tissue by
`the radiation.
`[0011] Radiographic imaging systems are commonly used
`in conjunction with external beam radiation systems (e.g.,
`linear accelerators) to identify and target tissues. Targeting an
`external beam of radiation to a specific volume of interest
`requires a means of delineating the target tissues (e.g., a
`tumor), which have certain radiographic properties, from the
`surrounding non-target tissues (e.g., bone, soft tissue) which
`have different radiographic properties. There are different
`methods of delineating target tissue from non-target tissue
`using these differences in radiographic properties of the tis(cid:173)
`sues. One such method is the insertion of radiographic mark(cid:173)
`ers around the targets volume's surface (or filing a cavity
`within the target) which further delineates the different radio(cid:173)
`graphic properties of the tissues. The inserted markers are
`more radio-opaque than either the target tissue or the non(cid:173)
`target tissue which allows the precise focusing of the external
`beam radiation to the target tissue. An example of such a
`method and markers can be found in copending, commonly
`assigned U.S. patent application Ser. No. 2005/0101860, filed
`Nov. 7, 2003, titled "Tissue Positioning Systems and Methods
`for Use with Radiation Therapy" which is incorporated by
`reference herein.
`
`SUMMARY OF THE INVENTION
`
`[0012] The present invention provides methods, systems
`and devices for treating a proliferative tissue disorder by
`positioning tissue surrounding a resected tissue cavity and
`applying external radiation. The method includes first surgi(cid:173)
`cally resecting at least a portion of proliferative tissue and
`thereby creating a resection cavity. A tissue fixation device
`having an expandable surface is then provided, the expand(cid:173)
`able surface being sized and configured to reproducibly posi(cid:173)
`tion tissue surrounding the resection cavity in a predeter(cid:173)
`mined geometry upon expansion of the expandable surface
`into an expanded position. Next, the expandable-surface is
`positioned within the resection cavity and the expandable
`surface is expanded to position the tissue surrounding the
`resection cavity in the predetermined geometry. Finally, an
`external radiation treatment is applied to the tissue surround(cid:173)
`ing the resection cavity.
`[0013]
`In another aspect of the invention, the resected cav(cid:173)
`ity and the expanded tissue fixation device positioned therein
`can be visualized in three dimensions. The invention can also
`preferably include applying at least one of an external beam
`radiation treatment, a three-dimensional conformational
`radiation therapy treatment, and an intensity modulation
`radiation therapy treatment. The method may further include
`repeating the treatment steps several times during a treatment
`regimen.
`[0014]
`In one embodiment, the expandable surface of the
`tissue fixation device includes a solid distensible surface
`defining a closed distensible chamber, and in a further
`embodiment the tissue fixation device is a balloon catheter. In
`yet a further embodiment, a second balloon can be positioned
`with in the first balloon. The balloons can be expanded with a
`
`variety of mediums including a non-radioactive substance. In
`other aspects of the invention, a treatment material is used to
`expand the balloon. The treatment material can include a drug
`such as a chemotherapy drug which is delivered through the
`wall of the balloon to the surrounding tissue.
`[0015]
`In another aspect of the present invention, fiducial
`markers can be positioned on the tissue fixation device to
`determine the spatial location of the device and the surround(cid:173)
`ing PTV. For example, by determining the spatial position of
`the markers relative to the origin of a coordinate system of the
`treatment room (e.g., relative to the treatment beam isocenter
`or beam source), the location of the device and the PTV can be
`compared to their desired locations. If there are any changes
`in the PTV or in the location of the device, adjustments can be
`made to the position of the patient's body, the device, and/or
`the direction and/or shape of the planned radiation beams
`prior to initiation of the radiation fraction. The fiducial mark(cid:173)
`ers and their detection systems can be radio-opaque markers
`that are imaged radiographically or transponders that signal
`their position to a receiver system.
`[0016] Another embodiment of the present invention
`includes a system for treating tissue surrounding a resected
`cavity that is subject to a proliferative tissue disorder. The
`system includes a tissue fixation device having a catheter
`body member with a proximal end, a distal end, an inner
`lumen, and an expandable surface element disposed proxi(cid:173)
`mate to the distal end of the body member, the expandable
`surface element being sized and configured to reproducibly
`position tissue surrounding a resected tissue cavity in a pre(cid:173)
`determined geometry upon expansion. An external radiation
`device is positioned outside the resected cavity such that the
`external radiation device can deliver a dose of radiation to the
`tissue surrounding the expandable surface element. With the
`tissue fixation device positioned within the resected tissue
`cavity and expanded to position the surrounding tissue, the
`accuracy of radiation from the external radiation device is
`greatly improved.
`[0017]
`in yet a further embodiment, the invention includes
`a device for treating a proliferative tissue disorder after a
`lumpectomy procedure. The device including an elongate
`body member having an open proximal end defining a pro xi(cid:173)
`mal port, a distal end and an inner lumen extending from the
`open proximal end, the elongate body member being sized for
`delivering an expandable surface element into a resection
`cavity created by a lumpectomy procedure. A spatial volume
`is defined by an expandable surface element disposed proxi(cid:173)
`mate to the distal end of the body member, the expandable
`surface element sized and configured to reproducibly position
`tissue surrounding a resected tissue cavity in a predetermined
`geometry upon expansion. The expandable surface element is
`size to fill a tissue cavity created in a breast during a lumpec(cid:173)
`tomy procedure so as to position the surrounding tissue and
`allow an external radiation source to accurately deliver a dose
`of radiation. This invention generally relates to a method and
`device for the improved targeting of tissues during external
`beam radiation therapy (EBRT). Improved targeting of tis(cid:173)
`sues during EBRT would allow for reduced volumes of tissue
`surrounding the target site that receives a therapeutic dose of
`radiation. Lower doses of radiation to non-target tissues
`would lower complications due to tissue toxicities as well as
`allowing for a reduction in the fractionation scheme.
`[0018] The device of the present invention is comprised of
`a catheter with a proximal and distal end, connected to an
`expandable reservoir on the distal end such as a balloon.
`
`Focal Exhibit 1013 Page 3
`
`

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`US 2008/0177179 A1
`
`Jul. 24, 2008
`
`3
`
`In another aspect of the present invention, a device
`[0019]
`does not use a balloon catheter to target tissue. The device
`may be comprised of a catheter or introduction device for the
`placement ofbiocompatible materials, (foam, plastic, etc.) to
`occupy a resected tissue or natural cavity. The biocompatible
`material may or may not contain contrast medium.
`[0020] The placement device serves as a guide for a suit(cid:173)
`ably protected radiation source which is able to increase the
`radiation delivered to the target tissue from within the body.
`The placement device may also be used to guide other tools
`including those for treatment such as tools for the application
`of energy (e.g., heat, microwave, RF, etc.) to resect portions of
`tissue from the surrounding area.
`In yet another aspect of the present invention, the
`[0021]
`biocompatible materials are bioabsorbable. Once the bio(cid:173)
`compatible materials are placed within the resected tissue or
`cavity, the material may remain within the patient's body for
`a period sufficient to complete the course of therapeutic treat(cid:173)
`ment. Once the course of therapeutic treatment has been
`completed, the biocompatible material will be absorbed into
`the patient's body thus removing the requirement of addi(cid:173)
`tional invasive surgery or an additional visit to a doctor's
`office to undergo a procedure to remove a medical device.
`
`DETAILED DESCRIPTION OF THE INVENTION
`
`[0022] The present invention provides systems and meth(cid:173)
`ods for treating proliferative tissue disorders, such as malig(cid:173)
`nant tumors of the breast, by surgically resecting at least a
`portion of the proliferative tissue to create a resection cavity,
`followed by external radiation therapy of residual tumor mar(cid:173)
`gin. To improve the accuracy of the radiation treatment, a
`tissue fixation device is provided to position and/or stabilize
`the tissue surrounding the resected cavity.
`[0023] External radiation therapies rely on precise imaging
`and/or targeting techniques, and any movement of the target
`tissue can introduce error. Patient positioning is often critical
`and great measures are taken to position and immobilize
`patients, including for example, marking the patient's skill
`and using foam body casts. Yet even with the patient immo(cid:173)
`bilized, shifting of the target tissue still presents a problem,
`including for example, shifting of tissue as a result of the
`patient breathing and inconsistencies in the positioning of the
`patient's body between radiotherapy fractions.
`[0024] Tissue cavities present an even greater difficulty
`because the tissue surrounding the cavity is often soft, irregu(cid:173)
`lar tissue which lacks the support usually provided by adja(cid:173)
`cent tissue. The irregular surface of the cavity wall, including
`the residual tumor margin, is therefore difficult to image.
`Unpredictable shifting of the tissue surrounding the cavity,
`possibly caused by slight patient movement, can further com(cid:173)
`plicate the procedure and result in unacceptable movement of
`the target tissue. For example, where the target tissue changes
`position after visualization, but before radiation treatment,
`the shifting tissue may result in radiation beams encountering
`primarily healthy tissue. As a result, the residual tumor mar(cid:173)
`gin may be substantially untreated, while healthy tissue may
`be damaged by the treatment. The present invention over(cid:173)
`comes these prior art problems by providing a tissue position(cid:173)
`ing device which can be inserted into the resected cavity and
`expanded to position the surrounding tissue in a predeter(cid:173)
`mined geometry. The methods of the present invention also
`facilitate tissue imaging by positioning tissue against a
`defined surface.
`
`[0025] The methods of the present invention also provide
`for systems and methods for the treatment of early stage
`breast cancers. For example, a breast cancer is removed sur(cid:173)
`gically by resecting a lesion to create a resection cavity. After
`resection, the margin of the cavity is exposed to external beam
`radiation therapy. In order to improve the accuracy of the
`radiation treatment, a tissue fixation device is provided to
`position and/or stabilize the tissue surrounding the resected
`cavity. The method of the present invention provides for a
`means for directing or targeting the radiation beams using
`radiographic imaging of the device or other fiducial markers
`with real-time feedback for direction of the radiation beams.
`[0026] The method of the present invention is based upon
`features of a balloon brachytherapy catheter (e.g., Mam(cid:173)
`moSite System, Cytyc Corporation, Marlborough Mass.) as
`provided in U.S. Pat. Nos. 5,611,923 and 5,931,774, to Wil(cid:173)
`liams eta!. and U.S. Pat. Nos. 6,200,257 and 6,413,204, and
`6,482,142 to Winkler eta!. all of which are incorporated by
`reference herein. Features of a balloon brachytherapy cath(cid:173)
`eterwhich serves to bring radiation of the lumpectomy cavity
`margins can be applied in the method of the present invention
`for external beam radiation sources. Specifically, the implan(cid:173)
`tation and inflation of a balloon catheter within a lumpectomy
`cavity provides for internal target fixation; external target
`fixation; and target localization.
`[0027] The use of a balloon brachytherapy catheter allows
`for the fixation of an internal target.
`[0028] The inflation of a balloon brachytherapy catheter in
`a resected lumpectomy cavity configures the target volume
`reproducibly in a shaped geometry (i.e., a spherical).
`[0029] Having a regular and reproducible target volume
`allows for easier and more efficient radiation beam shaping to
`conform the radiation therapy to the target tissue, thus mini(cid:173)
`mizing the radiation delivered to the adjacent healthy tissue.
`A more focused radiation beam also allows for reducing the
`size of the normal tissue margins typically added to the plan(cid:173)
`ning target volume (PTV).
`[0030] The use of a balloon brachytherapy catheter also
`allows for the fixation of an external target. A portion of an
`implanted brachytherapy device will extend percutaneously
`through the skin. This external portion of the device can be
`coupled to a rigid fixture providing a means for holding-the
`target volume (i.e., the tissue surrounding the balloon) fixed
`relative to the 3-dimensional space of the treatment facilities
`(e.g., a radiation treatment couch). Thus, while the target
`volume is held in a constant position in regard to an external
`fixture, other patient tissue (e.g., breast tissue) remains
`slightly mobile relative to the same external fixture or even
`relative to the patient's body (e.g., chest wall). The fixation of
`the target tissue by an external means allows for better target(cid:173)
`ing of the radiation beams which again allows for reducing
`the size of the normal tissue margins typically added to the
`planning target volume. Also, the fixation of target tissue to an
`external fixture reduces the movement of target tissue due to
`movement of the patient. For instance, even the slightest
`movement of a patient can have a deleterious effect on locat(cid:173)
`ing and targeting tissues. In particular, the target motion of
`lumpectomy cavities due to a patient's respiration can affect
`beam efficiencies. Thus, the fixation of target tissue can
`reduce or eliminate the movement of target tissue by invol(cid:173)
`untary patient movements.
`[0031] The use of a balloon brachytherapy catheter also
`allows for target localization. A brachytherapy balloon
`inflated with air or other contrast material provides a radio-
`
`Focal Exhibit 1013 Page 4
`
`

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`US 2008/0177179 A1
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`Jul. 24, 2008
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`4
`
`graphic method for real time aiming of the planned radiation
`beams. The location of the inflated device can be otherwise
`ascertained via a number of other fiducial marking systems
`that can telegraph their location within the treatment room
`(specifically relative to the linear accelerator's isocenter). An
`example of this capability is target localization via the Bea(cid:173)
`con® Electromagnetic Transponder (Calypso Medical
`Seattle, Wash.). Thus, radiation beams can be shaped on the
`fly to account for target location changes or can provide a
`means to tum the beam on and off as the target moves in space
`and intersects the beams.
`[0032] The present invention including a system for treat(cid:173)
`ing tissue surrounding a resected cavity that is subject to a
`proliferative tissue disorder. The system includes a tissue
`fixation device which includes a catheter body member hav(cid:173)
`ing a proximal end, a distal end, an inner lumen and an
`expandable surface element. Expandable surface element is
`preferably disposed proximate to distal end of catheter body
`member and is sized and configured to reproducibly position
`tissue surrounding a resected tissue cavity in a predetermined
`geometry upon expansion. The system also includes an exter(cid:173)
`nal radiation device positioned outside the resected cavity
`such that external radiation device can deliver a dose of radia(cid:173)
`tion to the tissue surrounding expandable surface element.
`External radiation device can be any external radiation source
`known in the art or later developed, however, in preferred
`embodiments of the invention, precisely targeted sources
`such as those used in 3DCRT and IMT are employed. The
`tissue fixation device can be positioned within a resected
`tissue cavity, for example within a patient's breast following
`a lumpectomy, and expanded to position the surrounding
`tissue such that the dose of radiation beams from external
`radiation device is accurately delivered.
`[0033] The expandable surface of the device can be defined
`by an inflatable balloon. It will be understood that the term
`"balloon" is intended to include distensible devices which can
`be, but need not be, constructed of an elastic material. The
`balloon of the present invention may include the variety of
`balloons or other distensible devices designed for use with
`surgical catheters. The balloon can be expanded by injecting
`an inflation material through body and into the balloon, and
`preferably, the inflation material comprises non-radioactive
`liquids or gases.
`In one embodiment, the balloon is constructed of a
`[0034]
`solid material that is substantially impermeable to active
`components of a treatment fluid with which it can be filled,
`and is also impermeable to body fluids, e.g., blood, cere(cid:173)
`brospinal fluid, and the like. An impermeable balloon is use(cid:173)
`ful in conjunction with a treatment fluid, to prevent the mate(cid:173)
`rial from escaping the treatment device and contaminating the
`surgical field or tissues of the patient.
`In another embodiment, the balloon is permeable to
`[0035]
`a treatment fluid, and permits a treatment fluid to pass out of
`device and into a body lumen or cavity. A permeable balloon
`is useful when the treatment fluid is a drug such as for
`example, a chemotherapeutic agent which must contact tissue
`to be effective. U.S. Pat. Nos. 5,611,923 and 5,931,774 to
`Williams et a!. disclose exemplary permeable balloons and
`treatment substances. Semi-permeable balloons can also find
`use in the method of the present invention. For example, a
`semi-permeable material that is capable of preventing the
`passage of a material through the balloon wall can be used to
`contain a treatment fluid, where certain fluid components can
`pass through the membrane while the components of the
`
`treatment fluid are retained within the balloon. Examples of
`which can be found in co-pending, commonly assigned U.S.
`patent application Ser. No. 2005-0107653.
`In another embodiment, materials may be impreg(cid:173)
`[0036]
`nated or incorporated into the expandable surface of the
`implantable device. For example, the expandable surface may
`be made of metal, be coated with a metal, or may contain
`metal in a matrix which is integrated into the expandable
`surface of the device. When the expandable surface is
`deployed in a patient's body, the metal in the expandable
`surface provides contrast between soft tissue and the surface
`of the device and thus imaging capability of the device
`becomes integral to the device (i.e., no longer needs a contrast
`agent). Examples of metals which may be incorporated into
`the expandable surface include any high Z material such as
`gold, silver, tungsten, etc., or stretchable metallized fabric
`mesh which is preferably knitted from a nylon and spandex
`knit plated with gold or other conductive material.
`[0037] Although the balloon and body member can mate in
`a variety of ways, in some embodiments, the balloon is mated
`to body member at substantially a single point on, or a single
`side of, the balloon body. Such attachment permits the bal(cid:173)
`loon (e.g., a spherical balloon) to maintain a substantially
`constant (e.g., spherical) shape over a range of inflation vol(cid:173)
`umes. That is, the balloon is not constrained in shape by
`multiple attachment points to the body member, as is com(cid:173)
`monly the case with, e.g., balloons for Foley catheters. In
`other embodiments, the balloon is attached to the body mem(cid:173)
`ber at multiple points on the balloon body, while allowing the
`balloon to maintain a constant shape over a range of inflation
`sizes. For example, a balloon attached to a body member at
`both distal and proximal points on the balloon body can be
`unconstrained upon inflation where the body member
`includes an expansion element (e.g., a slidable engagement
`element) that permits the body member to adjust in length as
`the balloon expands or contracts. A balloon which maintains
`a substantially constant shape over a range of inflation vol(cid:173)
`umes permits a surgeon to select a balloon with less concern
`over the size of the cavity.
`[0038] The body member of device provides a means for
`positioning expandable surface within the resected tissue cav(cid:173)
`ity and provides a path for delivering inflation material (if
`used).
`[0039] Although the exemplary body members have a tubu(cid:173)
`lar construction, one of skill in the art will appreciate that
`body members can have a variety of shapes and sizes. Body
`members suitable for use in the invention can include cath(cid:173)
`eters which are known in the art. Although body members can
`be constructed of a variety of materials, in one embodiment
`the body member material is silicone, preferably a silicone
`that is at least partially radio-opaque, thus facilitating x-ray
`location of body member after insertion of device. The body
`members can also include conventional adapters for attach(cid:173)
`ment to a treatment fluid receptacle and the balloon, as well as
`devices, e.g., right-angle devices, for conforming body mem(cid:173)
`bers to contours of the patient's body.
`[0040] The position of the device with in a patient's body
`can also be determined using fiducial markers. By positioning
`the markers on the device (for example on expandable surface
`member or on body member), a user can determine the spatial
`position of the device and the surrounding target tissue. The
`spatial data can be used to correct errors in target tissue
`location by adjusting the patient's body location on the treat-
`
`Focal Exhibit 1013 Page 5
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`

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`US 2008/0177179 A1
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`Jul. 24, 2008
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`5
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`ment couch or by altering the radiotherapy beams' shape and
`direction. Fiducial markers are discussed in more detail
`below.
`[0041] The device of the present invention can also include
`a variety of alternative embodiments designed to facilitate
`tissue positioning. For example, the device can include mul(cid:173)
`tiple spatial volumes, as well as, a variety of shapes adapted to
`conform and shape the resected cavity. In addition, the
`expandable surface can be positioned on and mated with
`tubular body member in various ways to facilitate placement
`of the expandable surface within a tissue cavity. The expand(cid:173)
`able surface can also be adapted to allow delivery of a treat(cid:173)
`ment material to the tissue surrounding the cavity.
`[0042] The invention also contemplates the use of multiple
`balloons, e.g., a double-walled structure. Such a balloon can
`comprise, for example, an impermeable inner wall and a
`permeable outer wall. In this embodiment, the inner