Method and apparatus for uniform radiation treatment of vascular lumens

Claim 1

An apparatus for localized intravascular radiotherapy of a tortuous blood vessel, such as a coronary artery, comprising: a catheter comprising an elongate member having a proximal section and a distal section, the distal section including a distal tip, said catheter being sized and of sufficient flexibility for introduction into a lumen of a patient's vascular system and advancement therethrough until the distal tip is disposed near a predetermined target area of tissue along the wall of the tortuous blood vessel, said elongate member having a longitudinal bore, the longitudinal bore having an opening in the proximal section and terminating proximate to the distal tip to form a treatment channel within said catheter for advancement of a radioactive source wire therein; and means for substantially centering the treatment channel radially within the lumen of the tortuous blood vessel over a predetermined length of treatment channel despite curvature of the blood vessel, in at least said predetermined target area; whereby a radioactive source wire, including a distal end having a radioactive source assembled thereto, when advanced along the treatment channel until the radioactive source is disposed at the target area, will have said radioactive source maintained substantially at the radial center of the lumen throughout the target area for delivery of a substantially uniform dosage of radiation to tissue at the wall of the blood vessel in the target area circumferentially about said source throughout a predetermined treatment interval.

Claim 2

An apparatus for localized intravascular radiotherapy of a tortuous blood vessel, such as a coronary artery, comprising: a catheter comprising an elongate member having a proximal section and a distal section, the distal section including a distal tip, said catheter being sized and of sufficient flexibility for introduction into a lumen of a patient's vascular system and advancement therethrough until the distal tip is disposed near a predetermined target area of tissue along the wall of the tortuous blood vessel, said elongate member having a longitudinal bore, the longitudinal bore having an opening in the proximal section and terminating proximate to the distal tip to form a treatment channel within said catheter for advancement of a radioactive source wire therein; and means for substantially centering the treatment channel radially within the lumen of the tortuous blood vessel over a predetermined length of treatment channel despite curvature of the blood vessel, in at least said predetermined target area; whereby a radioactive source wire, including a distal end having a radioactive source assembled thereto, when advanced along the treatment channel until the radioactive source is disposed at the target area, will have said radioactive source maintained substantially at the radial center of the lumen throughout the target area for delivery of a substantially uniform dosage of radiation to tissue at the wall of the blood vessel in the target area circumferentially about said source throughout a predetermined treatment interval.

Claim 3

An apparatus for localized intravascular radiotherapy of a tortuous blood vessel, such as a coronary artery, comprising: a catheter comprising an elongate member having a proximal section and a distal section, the distal section including a distal tip, said catheter being sized and of sufficient flexibility for introduction into a lumen of a patient's vascular system and advancement therethrough until the distal tip is disposed near a predetermined target area of tissue along the wall of the tortuous blood vessel, said elongate member having a longitudinal bore, the longitudinal bore having an opening in the proximal section and terminating proximate to the distal tip to form a treatment channel within said catheter for advancement of a radioactive source wire therein; and means for substantially centering the treatment channel radially within the lumen of the tortuous blood vessel in at least said predetermined target area; whereby a radioactive source wire, including a distal end having a radioactive source assembled thereto, when advanced along the treatment channel until the radioactive source is disposed at the target area, will have said radioactive source maintained substantially at the radial center of the lumen at the target area for delivery of a substantially uniform dosage of radiation to tissue at the wall of the blood vessel in the target area circumferentially about said source; said centering means comprising a wire form, said wire form comprising at least one wire mesh tube having a proximal end and a distal end slidably assembled over said elongate member; the distal end of said at least one wire mesh tube being attached to said elongate member proximate to the distal end thereof; further including a sleeve comprising a hollow, flexible, elongate tube having a proximal end and a distal end, said sleeve being slidably assembled over said elongate member, the proximal end of said wire mesh tube being attached to the distal end of said sleeve; whereby said at least one wire mesh tube is expanded radially to compliantly engage the interior surface of the blood vessel by exertion of an axial force along said sleeve to axially compress said wire mesh tube.

Claim 4

An apparatus for localized intravascular radiotherapy of a tortuous blood vessel, such as a coronary artery, comprising: a catheter comprising an elongate member having a proximal section and a distal section, the distal section including a distal tip, said catheter being sized and of sufficient flexibility for introduction into a lumen of a patient's vascular system and advancement therethrough until the distal tip is disposed near a predetermined target area of tissue along the wall of the tortuous blood vessel, said elongate member having a longitudinal bore, the longitudinal bore having an opening in the proximal section and terminating proximate to the distal tip to form a treatment channel within said catheter for advancement of a radioactive source wire therein; and means for substantially centering the treatment channel radially within the lumen of the tortuous blood vessel in at least said predetermined target area; whereby a radioactive source wire, including a distal end having a radioactive source assembled thereto, when advanced along the treatment channel until the radioactive source is disposed at the target area, will have said radioactive source maintained substantially at the radial center of the lumen at the target area for delivery of a substantially uniform dosage of radiation to tissue at the wall of the blood vessel in the target area circumferentially about said source; said centering means comprising a wire form, said wire form comprising at least one wire mesh tube having a proximal end and a distal end slidably assembled over said elongate member; the distal end of said at least one wire mesh tube being attached to said elongate member proximate to the distal end thereof; further including a sleeve comprising a hollow, flexible, elongate tube having a proximal end and a distal end, said sleeve being slidably assembled over said elongate member, the proximal end of said wire mesh tube being attached to the distal end of said sleeve; whereby said at least one wire mesh tube is expanded radially to compliantly engage the interior surface of the blood vessel by exertion of an axial force along said sleeve to axially compress said wire mesh tube.

Claim 13

An apparatus for localized intravascular radiotherapy of a tortuous blood vessel, such as a coronary artery, comprising: a catheter comprising an elongate member having a proximal section and a distal section, the distal section including a distal tip, said catheter being sized and of sufficient flexibility for introduction into a lumen of a patient's vascular system and advancement therethrough until the distal tip is disposed near a predetermined target area of tissue along the wall of the tortuous blood vessel, said elongate member having a longitudinal bore, the longitudinal bore having an opening in the proximal section and terminating proximate to the distal tip to form a treatment channel within said catheter for advancement of a radioactive source wire therein; and means for substantially centering the treatment channel radially within the lumen of the tortuous blood vessel in at least said predetermined target area, said centering means comprising a balloon positioned and adapted to be inflated to compliantly engage the interior surface along a portion of the wall of the tortuous blood vessel, said balloon including a distal end and a proximal end, said balloon being attached to said catheter at the proximal and distal ends of said balloon and at a location between the distal and proximal ends of said balloon to leave portions of the balloon unattached to the catheter between the proximal and distal ends thereof; whereby a radioactive source wire, including a distal end having a radioactive source assembled thereto, when advanced along the treatment channel until the radioactive source is disposed at the target area, will have said radioactive source maintained substantially at the radial center of the lumen at the target area for delivery of a substantially uniform dosage of radiation to tissue at the wall of the blood vessel in the target area circumferentially about said source; further including radio-opaque markers fixed to said catheter proximate to each of the distal end and the proximal end of the balloon to facilitate fluoroscopic observation of positioning of the balloon in the target area for irradiation of a region of the blood vessel corresponding to the length of the balloon engaging the interior surface of the blood vessel.

Claim 14

An apparatus for localized intravascular radiotherapy of a tortuous blood vessel, such as a coronary artery, comprising: a catheter comprising an elongate member having a proximal section and a distal section, the distal section including a distal tip, said catheter being sized and of sufficient flexibility for introduction into a lumen of a patient's vascular system and advancement therethrough until the distal tip is disposed near a predetermined target area of tissue along the wall of the tortuous blood vessel, said elongate member having a longitudinal bore, the longitudinal bore having an opening in the proximal section and terminating proximate to the distal tip to form a treatment channel within said catheter for advancement of a radioactive source wire therein; and means for substantially centering the treatment channel radially within the lumen of the tortuous blood vessel in at least said predetermined target area, said centering means comprising a balloon positioned and adapted to be inflated to compliantly engage the interior surface along a portion of the wall of the tortuous blood vessel, said balloon including a distal end and a proximal end, said balloon being attached to said catheter at the proximal and distal ends of said balloon and at a location between the distal and proximal ends of said balloon to leave portions of the balloon unattached to the catheter between the proximal and distal ends thereof; whereby a radioactive source wire, including a distal end having a radioactive source assembled thereto, when advanced along the treatment channel until the radioactive source is disposed at the target area, will have said radioactive source maintained substantially at the radial center of the lumen at the target area for delivery of a substantially uniform dosage of radiation to tissue at the wall of the blood vessel in the target area circumferentially about said source; further including radio-opaque markers fixed to said catheter proximate to each of the distal end and the proximal end of the balloon to facilitate fluoroscopic observation of positioning of the balloon in the target area for irradiation of a region of the blood vessel corresponding to the length of the balloon engaging the interior surface of the blood vessel.

Claim 15

An apparatus for localized intravascular radiotherapy of a tortuous blood vessel, such as a coronary artery, comprising: a catheter comprising an elongate member having a proximal section and a distal section, the distal section including a distal tip, said catheter being sized and of sufficient flexibility for introduction into a lumen of a patient's vascular system and advancement therethrough until the distal tip is disposed near a predetermined target area of tissue along the wall of the tortuous blood vessel, said elongate member having a longitudinal bore, the longitudinal bore having an opening in the proximal section and terminating proximate to the distal tip to form a treatment channel within said catheter for advancement of a radioactive source wire therein, the proximal section of said elongate member of the catheter further including an afterloader connector; and means for substantially centering the treatment channel radially within the lumen of the tortuous blood vessel in at least said predetermined target area; whereby a radioactive source wire, including a distal end having a radioactive source assembled thereto, when advanced along the treatment channel until the radioactive source is disposed at the target area, will have said radioactive source maintained substantially at the radial center of the lumen at the target area for delivery of a substantially uniform dosage of radiation to tissue at the wall of the blood vessel in the target area circumferentially about said source.

Claim 16

An apparatus for localized intravascular radiotherapy of a tortuous blood vessel, such as a coronary artery, comprising: a catheter comprising an elongate member having a proximal section and a distal section, the distal section including a distal tip, said catheter being sized and of sufficient flexibility for introduction into a lumen of a patient's vascular system and advancement therethrough until the distal tip is disposed near a predetermined target area of tissue along the wall of the tortuous blood vessel, said elongate member having a longitudinal bore, the longitudinal bore having an opening in the proximal section and terminating proximate to the distal tip to form a treatment channel within said catheter for advancement of a radioactive source wire therein, the proximal section of said elongate member of the catheter further including an afterloader connector; and means for substantially centering the treatment channel radially within the lumen of the tortuous blood vessel in at least said predetermined target area; whereby a radioactive source wire, including a distal end having a radioactive source assembled thereto, when advanced along the treatment channel until the radioactive source is disposed at the target area, will have said radioactive source maintained substantially at the radial center of the lumen at the target area for delivery of a substantially uniform dosage of radiation to tissue at the wall of the blood vessel in the target area circumferentially about said source.

Claim 17

An apparatus for localized intravascular radiotherapy of a tortuous blood vessel, such as a coronary artery, comprising: a catheter comprising an elongate member having a proximal section and a distal section, the distal section including a distal tip, said catheter being sized and of sufficient flexibility for introduction into a lumen of a patient's vascular system and advancement therethrough until the distal tip is disposed near a predetermined target area of tissue along the wall of the tortuous blood vessel, said elongate member having a longitudinal bore, the longitudinal bore having an opening in the proximal section and terminating proximate to the distal tip to form a treatment channel within said catheter for advancement of a radioactive source wire therein; and means for substantially centering the treatment channel radially within the lumen of the tortuous blood vessel in at least said predetermined target area; whereby a radioactive source wire, including a distal end having a radioactive source assembled thereto, when advanced along the treatment channel until the radioactive source is disposed at the target area, will have said radioactive source maintained substantially at the radial center of the lumen at the target area for delivery of a substantially uniform dosage of radiation to tissue at the wall of the blood vessel in the target area circumferentially about said source; further including an over-the-wire guidewire lumen, said over-the-wire guidewire lumen comprising a first longitudinal hole in said elongate member, said first longitudinal hole having an opening in the proximal section and an opening at the distal tip of said elongate member.

Claim 18

An apparatus for localized intravascular radiotherapy of a tortuous blood vessel, such as a coronary artery, comprising: a catheter comprising an elongate member having a proximal section and a distal section, the distal section including a distal tip, said catheter being sized and of sufficient flexibility for introduction into a lumen of a patient's vascular system and advancement therethrough until the distal tip is disposed near a predetermined target area of tissue along the wall of the tortuous blood vessel, said elongate member having a longitudinal bore, the longitudinal bore having an opening in the proximal section and terminating proximate to the distal tip to form a treatment channel within said catheter for advancement of a radioactive source wire therein; and means for substantially centering the treatment channel radially within the lumen of the tortuous blood vessel in at least said predetermined target area; whereby a radioactive source wire, including a distal end having a radioactive source assembled thereto, when advanced along the treatment channel until the radioactive source is disposed at the target area, will have said radioactive source maintained substantially at the radial center of the lumen at the target area for delivery of a substantially uniform dosage of radiation to tissue at the wall of the blood vessel in the target area circumferentially about said source; further including an over-the-wire guidewire lumen, said over-the-wire guidewire lumen comprising a first longitudinal hole in said elongate member, said first longitudinal hole having an opening in the proximal section and an opening at the distal tip of said elongate member.

Claim 19

An apparatus for localized intravascular radiotherapy of a tortuous blood vessel, such as a coronary artery, comprising: a catheter comprising an elongate member having a proximal section and a distal section, the distal section including a distal tip, said catheter being sized and of sufficient flexibility for introduction into a lumen of a patient's vascular system and advancement therethrough until the distal tip is disposed near a predetermined target area of tissue along the wall of the tortuous blood vessel, said elongate member having a longitudinal bore, the longitudinal bore having an opening in the proximal section and terminating proximate to the distal tip to form a treatment channel within said catheter for advancement of a radioactive source wire therein; and means for substantially centering the treatment channel radially within the lumen of the tortuous blood vessel in at least said predetermined target area, said centering means comprising a balloon positioned and adapted to be inflated to compliantly engage the interior surface along a portion of the wall of the tortuous blood vessel; whereby a radioactive source wire, including a distal end having a radioactive source assembled thereto, when advanced along the treatment channel until the radioactive source is disposed at the target area, will have said radioactive source maintained substantially at the radial center of the lumen at the target area for delivery of a substantially uniform dosage of radiation to tissue at the wall of the blood vessel in the target area circumferentially about said source; further including an over-the-wire guidewire lumen, said over-the-wire guidewire lumen comprising a first longitudinal hole in said elongate member, said first longitudinal hole having an opening in the proximal section and an opening at the distal tip of said elongate member.

Claim 20

An apparatus for localized intravascular radiotherapy of a tortuous blood vessel, such as a coronary artery, comprising: a catheter comprising an elongate member having a proximal section and a distal section, the distal section including a distal tip, said catheter being sized and of sufficient flexibility for introduction into a lumen of a patient's vascular system and advancement therethrough until the distal tip is disposed near a predetermined target area of tissue along the wall of the tortuous blood vessel, said elongate member having a longitudinal bore, the longitudinal bore having an opening in the proximal section and terminating proximate to the distal tip to form a treatment channel within said catheter for advancement of a radioactive source wire therein; and means for substantially centering the treatment channel radially within the lumen of the tortuous blood vessel in at least said predetermined target area, said centering means comprising a balloon positioned and adapted to be inflated to compliantly engage the interior surface along a portion of the wall of the tortuous blood vessel; whereby a radioactive source wire, including a distal end having a radioactive source assembled thereto, when advanced along the treatment channel until the radioactive source is disposed at the target area, will have said radioactive source maintained substantially at the radial center of the lumen at the target area for delivery of a substantially uniform dosage of radiation to tissue at the wall of the blood vessel in the target area circumferentially about said source; further including an over-the-wire guidewire lumen, said over-the-wire guidewire lumen comprising a first longitudinal hole in said elongate member, said first longitudinal hole having an opening in the proximal section and an opening at the distal tip of said elongate member.

Claim 22

An apparatus for localized intravascular radiotherapy of a tortuous blood vessel, such as a coronary artery, comprising: a catheter comprising an elongate member having a proximal section and a distal section, the distal section including a distal tip, said catheter being sized and of sufficient flexibility for introduction into a lumen of a patient's vascular system and advancement therethrough until the distal tip is disposed near a predetermined target area of tissue along the wall of the tortuous blood vessel, said elongate member having a longitudinal bore, the longitudinal bore having an opening in the proximal section and terminating proximate to the distal tip to form a treatment channel within said catheter for advancement of a radioactive source wire therein; and means for substantially centering the treatment channel radially within the lumen of the tortuous blood vessel in at least said predetermined target area; whereby a radioactive source wire, including a distal end having a radioactive source assembled thereto, when advanced along the treatment channel until the radioactive source is disposed at the target area, will have said radioactive source maintained substantially at the radial center of the lumen at the target area for delivery of a substantially uniform dosage of radiation to tissue at the wall of the blood vessel in the target area circumferentially about said source; further including a distal monorail guidewire lumen, said lumen comprising a second longitudinal bore and a transverse opening; said second longitudinal bore extending from the distal tip of said elongate member to a point proximate to the distal end of the treatment channel; and said transverse opening comprising a hole intersecting said second longitudinal bore and opening to a lateral surface of said elongate member.

Claim 23

An apparatus for localized intravascular radiotherapy of a tortuous blood vessel, such as a coronary artery, comprising: a catheter comprising an elongate member having a proximal section and a distal section, the distal section including a distal tip, said catheter being sized and of sufficient flexibility for introduction into a lumen of a patient's vascular system and advancement therethrough until the distal tip is disposed near a predetermined target area of tissue along the wall of the tortuous blood vessel, said elongate member having a longitudinal bore, the longitudinal bore having an opening in the proximal section and terminating proximate to the distal tip to form a treatment channel within said catheter for advancement of a radioactive source wire therein; and means for substantially centering the treatment channel radially within the lumen of the tortuous blood vessel in at least said predetermined target area; whereby a radioactive source wire, including a distal end having a radioactive source assembled thereto, when advanced along the treatment channel until the radioactive source is disposed at the target area, will have said radioactive source maintained substantially at the radial center of the lumen at the target area for delivery of a substantially uniform dosage of radiation to tissue at the wall of the blood vessel in the target area circumferentially about said source; further including a distal monorail guidewire lumen, said lumen comprising a second longitudinal bore and a transverse opening; said second longitudinal bore extending from the distal tip of said elongate member to a point proximate to the distal end of the treatment channel; and said transverse opening comprising a hole intersecting said second longitudinal bore and opening to a lateral surface of said elongate member.

Claim 24

An apparatus for localized intravascular radiotherapy of a tortuous blood vessel such as a coronary artery, comprising: a catheter comprising an elongate member having a proximal section and a distal section, the distal section including a distal tip, said catheter being sized and of sufficient flexibility for introduction into a lumen of a patient's vascular system and advancement therethrough until the distal tip is disposed near a predetermined target area of tissue along the wall of the tortuous blood vessel said elongate member having a longitudinal bore, the longitudinal bore having an opening in the proximal section and terminating proximate to the distal tip to form a treatment channel within said catheter for advancement of a radioactive source wire therein; and means for substantially centering the treatment channel radially within the lumen of the tortuous blood vessel in at least said predetermined target area, said centering means comprising a balloon positioned and adapted to be inflated to compliantly engage the interior surface along a portion of the wall of the tortuous blood vessel; whereby a radioactive source wire, including a distal end having a radioactive source assembled thereto, when advanced along the treatment channel until the radioactive source is disposed at the target area, will have said radioactive source maintained substantially at the radial center of the lumen at the target area for delivery of a substantially uniform dosage of radiation to tissue at the wall of the blood vessel in the target area circumferentially about said source; further including a distal monorail guidewire lumen, said distal monorail guidewire lumen comprising a second longitudinal bore extending from the distal tip of said elongate member to a point proximate to the distal end of the treatment channel and a transverse opening comprising a hole intersecting said second longitudinal bore and opening to a lateral surface of said elongate member.

Claim 25

An apparatus for localized intravascular radiotherapy of a tortuous blood vessel such as a coronary artery, comprising: a catheter comprising an elongate member having a proximal section and a distal section, the distal section including a distal tip, said catheter being sized and of sufficient flexibility for introduction into a lumen of a patient's vascular system and advancement therethrough until the distal tip is disposed near a predetermined target area of tissue along the wall of the tortuous blood vessel said elongate member having a longitudinal bore, the longitudinal bore having an opening in the proximal section and terminating proximate to the distal tip to form a treatment channel within said catheter for advancement of a radioactive source wire therein; and means for substantially centering the treatment channel radially within the lumen of the tortuous blood vessel in at least said predetermined target area, said centering means comprising a balloon positioned and adapted to be inflated to compliantly engage the interior surface along a portion of the wall of the tortuous blood vessel; whereby a radioactive source wire, including a distal end having a radioactive source assembled thereto, when advanced along the treatment channel until the radioactive source is disposed at the target area, will have said radioactive source maintained substantially at the radial center of the lumen at the target area for delivery of a substantially uniform dosage of radiation to tissue at the wall of the blood vessel in the target area circumferentially about said source; further including a distal monorail guidewire lumen, said distal monorail guidewire lumen comprising a second longitudinal bore extending from the distal tip of said elongate member to a point proximate to the distal end of the treatment channel and a transverse opening comprising a hole intersecting said second longitudinal bore and opening to a lateral surface of said elongate member.

Claim 27

A method of intravascular radiotherapy treatment of a predetermined target area of tissue along a portion of the wall of a tortuous blood vessel, such as a coronary artery, comprising: introducing into the vascular system of a patient an elongate flexible member having a proximal end and a distal end and a longitudinal bore, and having a length and a diameter adapted to permit said member to traverse a tortuous path through a lumen of the patient's vascular system to said target area, said member further including means for centering said distal end radially in the lumen of the blood vessel over a predetermined length at said distal end substantially equivalent to the entire length of lumen of the target area despite curvature thereof attributable to the tortuosity of the blood vessel; advancing said member until the distal end is disposed within the target area of the blood vessel; radially centering the longitudinal bore along the entire length of lumen of the target area of the blood vessel by compliantly engaging the centering means with the wall of the blood vessel; advancing a source wire including a distal tip having a radioactive source assembled thereto along the longitudinal bore until the radioactive source is disposed within the lumen at the target area of the blood vessel; substantially centering the radioactive source radially in the lumen along the target area over a predetermined period of treatment time to deliver a substantially uniform dosage of radiation to tissue in a circumferential band about said source sufficient to inhibit hyperplasia of smooth muscle cells in the irradiated tissue; and withdrawing the source wire from the patient's vascular system upon completion of the predetermined period of treatment time.

Claim 28

A method of intravascular radiotherapy treatment of a predetermined target area of tissue along a portion of the wall of a tortuous blood vessel, such as a coronary artery, comprising: introducing into the vascular system of a patient an elongate flexible member having a proximal end and a distal end and a longitudinal bore, and having a length and a diameter adapted to permit said member to traverse a tortuous path through a lumen of the patient's vascular system to said target area, said member further including means for centering said distal end radially in the lumen of the blood vessel over a predetermined length at said distal end substantially equivalent to the entire length of lumen of the target area despite curvature thereof attributable to the tortuosity of the blood vessel; advancing said member until the distal end is disposed within the target area of the blood vessel; radially centering the longitudinal bore along the entire length of lumen of the target area of the blood vessel by compliantly engaging the centering means with the wall of the blood vessel; advancing a source wire including a distal tip having a radioactive source assembled thereto along the longitudinal bore until the radioactive source is disposed within the lumen at the target area of the blood vessel; substantially centering the radioactive source radially in the lumen along the target area over a predetermined period of treatment time to deliver a substantially uniform dosage of radiation to tissue in a circumferential band about said source sufficient to inhibit hyperplasia of smooth muscle cells in the irradiated tissue; and withdrawing the source wire from the patient's vascular system upon completion of the predetermined period of treatment time.

Claim 32

A method of inhibiting restenosis of a selected portion of a human coronary artery after angioplasty or other trauma to said selected portion, comprising: selecting a catheter comprising an elongate flexible member having a proximal section and a distal section, the distal section including a distal tip, said catheter further including a longitudinal bore having an opening in the proximal section and terminating proximate to the distal tip to form a treatment channel within said catheter, said treatment channel having a proximal portion and a distal portion, the distal section of said catheter further including means for substantially centering a length of the distal portion of the treatment channel substantially corresponding to the length of said selected portion of the artery radially within the lumen of the coronary artery despite curvature of the artery; introducing and advancing said catheter within the cardiovascular system of a patient to place the distal section of said catheter in proximity to said selected portion in the lumen of the coronary artery; engaging the centering means with the wall of the coronary artery to substantially center said distal portion length of the treatment channel radially in the lumen of the artery throughout the length of said selected portion thereof despite any said curvature of the artery over said length of the selected portion; advancing a source wire having a distal end along the treatment channel until a radioactive source assembled at said distal end of the source wire is disposed substantially at the radial center of the lumen of the coronary artery within said selected portion thereof, maintaining the radioactive source substantially at the radial center of the lumen of the coronary artery in advancement of the source along the length of said selected portion throughout a predetermined treatment period to deliver a substantially uniform dosage of radiation to tissue in a circumferential band about said radioactive source at the wall of the coronary artery in said selected portion thereof; and withdrawing the source wire from the patient upon completion of the treatment period.

Claim 33

A method of inhibiting restenosis of a selected portion of a human coronary artery after angioplasty or other trauma to said selected portion, comprising: selecting a catheter comprising an elongate flexible member having a proximal section and a distal section, the distal section including a distal tip, said catheter further including a longitudinal bore having an opening in the proximal section and terminating proximate to the distal tip to form a treatment channel within said catheter, said treatment channel having a proximal portion and a distal portion, the distal section of said catheter further including means for substantially centering a length of the distal portion of the treatment channel substantially corresponding to the length of said selected portion of the artery radially within the lumen of the coronary artery despite curvature of the artery; introducing and advancing said catheter within the cardiovascular system of a patient to place the distal section of said catheter in proximity to said selected portion in the lumen of the coronary artery; engaging the centering means with the wall of the coronary artery to substantially center said distal portion length of the treatment channel radially in the lumen of the artery throughout the length of said selected portion thereof despite any said curvature of the artery over said length of the selected portion; advancing a source wire having a distal end along the treatment channel until a radioactive source assembled at said distal end of the source wire is disposed substantially at the radial center of the lumen of the coronary artery within said selected portion thereof, maintaining the radioactive source substantially at the radial center of the lumen of the coronary artery in advancement of the source along the length of said selected portion throughout a predetermined treatment period to deliver a substantially uniform dosage of radiation to tissue in a circumferential band about said radioactive source at the wall of the coronary artery in said selected portion thereof; and withdrawing the source wire from the patient upon completion of the treatment period.