Implants for use in brachytherapy and other radiation therapy that resist migration and rotation

• US 20070021643A1
• Filed: 07/22/2005
• Published: 01/25/2007
• Est. Priority Date: 07/22/2005
• Status: Active Grant

• Current Assignee: Theragenics Corporation (Juniper Investment Co. LLC)
• Original Assignee: Worldwide Medical Technologies, LLC
• Inventors: Matons, James, Rice, Warren, Johnston, Warren, Bouffard, Matthew, Lamoureux, Gary
• Granted Patent: US 7,736,293 B2
• Time in Patent Office: Days
• US Class Current: 600/7
• CPC Class Codes: A61N 2005/1023 Means for creating a row of seeds, e.g. spacers
• CPC Class Codes: A61N 2005/1024 Seeds
• CPC Class Codes: A61N 5/1027 Interstitial radiation therapy

Abstract

In one embodiment a therapeutic member includes a radioactive source and a material (e.g., a bio-absorbable polymeric material) that encapsulates the radioactive source. An outer surface of the encapsulating material includes a plurality of protrusions to reduce a tendency of the member to migrate and rotate within a patient'"'"'s body after implantation. In an embodiment, the encapsulating material includes an anchor mechanism that extends from at least one of the longitudinal ends of the radioactive source to reduce a tendency of the member to migrate and rotate within a patient'"'"'s body after implantation. Embodiments of the present invention are also directed to strands that include similar protrusions and/or anchor mechanisms. Additionally, embodiments of the present invention are directed to spacers that resist migration and rotation. Embodiments are also directed to radiopaque markers that resist migration and rotation. This abstract is not intended to be a complete description of the invention.

Claims

1-46. -46. (canceled)

47. A spacer for use in separating radioactive sources from one another, comprising:

a first half;

a second half; and

a living hinge that connects the first and second halves and biases the first and second halves such that after the first and second halves are folded toward one another the first and second halves tend to unfold, causing the first and second halves to engage surrounding patient tissue after implantation and thereby reducing a tendency for the spacer to migrate and rotate after implantation.

48. The spacer of claim 47, wherein an outer surface of at least one of the first and second halves includes one or more protrusions.

49. A marker for use in radiation treatment, comprising:

a marker body including a radiopaque material; and

a polymeric material that encapsulates at least a portion of the marker body;

wherein an outer surface of the encapsulating material includes one or more protrusions to reduce a tendency of the marker to migrate and rotate within a patient'"'"'s body after implantation.

50. The marker of claim 49, wherein the polymeric material is bio-absorbable.

51. An anchor mechanism, comprising:

a sleeve to fit around a structure that is a radioactive source, a thermal ablation implant, a spacer, a strand or a radiopaque marker; and

one or more wings connected to the sleeve by a corresponding living hinge that enables the wing to be folded against the structure during implantation of the structure in a patient, wherein the living hinge biases the wing such that one end of the wing moves away from the structure to engage surrounding patient tissue after implantation of the structure into a patient, to thereby reduce a tendency for the structure to migrate and rotate after implantation.

52. A therapeutic member configured to be implanted in a similar manner as loose radioactive seeds are implanted, for use in brachytherapy, comprising:

a single radioactive source; and

a polymeric material molded to encapsulate the single radioactive source;

wherein an outer surface of the encapsulating material includes one or more protrusions to reduce a tendency of the member to migrate and rotate within a patient'"'"'s body after implantation.

53. The therapeutic member of claim 52, wherein the one or more protrusions are made from the polymeric material that encapsulates the single radioactive source.

54. The therapeutic member of claim 53, wherein the polymeric material is bio-absorbable.

55. The therapeutic member of claim 52, wherein the one or more protrusions are made of a non bio-absorbable material that is attached to the encapsulating material.

56. The therapeutic member of claim 52, wherein the single radioactive source comprises a single radioactive seed that includes radioactive material contained within a metallic housing, and wherein the polymeric material is molded to completely encapsulate the metallic housing of the seed.

57. The therapeutic member of claim 52, wherein an outer surface of the encapsulating material includes a plurality of ribbed shaped protrusions.

58. The therapeutic member of claim 57, wherein the one or more protrusions are defined by a shape of a mold that is used to encapsulate the seed.

59. The therapeutic member of claim 52, wherein the one or more protrusions include one or more ribs that encircle a radial circumference of the radioactive source.

60. The therapeutic member of claim 59, wherein the one or more ribs form one or more ring or a helix about the radial circumference of the radioactive source.

61. The therapeutic member of claim 59, wherein each rib extends at least 0.002 inches beyond portions of the material where there is not a protrusion.

62. The therapeutic member of claim 52, wherein the outer surface of the encapsulating material includes a plurality of the protrusions.

63. The therapeutic member of claim 52, wherein at least one of the plurality of protrusions extend at an acute angle with respect to a longitudinal axis of the radioactive source.

64. The therapeutic member of claim 52, wherein at least one of the plurality of protrusions extend in a radial direction with respect to the radioactive source.

65. The therapeutic member of claim 64, wherein one or more of the plurality of protrusions have one of the following shapes:

square;

rectangular;

circular;

triangular;

pyramidal;

oval; and

semi-spherical.

66. The therapeutic member of claim 52, wherein the plurality of protrusions form an irregular pattern on the outer surface of the encapsulating material.

67. The therapeutic member of claim 66, wherein the plurality of protrusions form a surface that resembles a rough stucco surface.

68. The therapeutic member of claim 52, wherein a thickness of the material that encapsulates the single radioactive seed is at least 0.002 inches.

69. The therapeutic member of claim 52, wherein at least one of the one or more protrusions extends at least 0.002 inches beyond portions of the material where there is not a protrusion.

70. The therapeutic member of claim 52, wherein the single radioactive source comprises a single radioactive rod.

71. The therapeutic member of claim 52, wherein the single radioactive source comprises a single radioactive coil.

72. The therapeutic member of claim 52, wherein the single radioactive source includes first and second longitudinal ends, and wherein the one or more protrusions include an anchor mechanism that extends from at least one of the longitudinal ends of the single radioactive source.

73. The therapeutic member of claim 52, wherein the single radioactive source includes first and second longitudinal ends, and wherein the one or more protrusions are located between the longitudinal ends of the single radioactive source.

74. A therapeutic member configured to be implanted in a similar manner as loose radioactive seeds are implanted, for use in brachytherapy, comprising:

a single radioactive source; and

a polymeric material that encapsulates at least a portion of the single radioactive source;

wherein an outer surface of the encapsulating material includes one or more protrusions to reduce a tendency of the member to migrate and rotate within a patient'"'"'s body after implantation.

75. A brachytherapy device, comprising:

a cartridge configured for use with a brachytherapy applicator; and

a plurality of anchor seeds stacked parallel to one another within the cartridge;

wherein each anchor seed includes a radioactive seed that is at least partially encapsulated by a polymeric material; and

wherein each anchor seed includes at least one protrusion on an outer surface of the encapsulating material to a reduce a tendency for the anchor seed to migrate and rotate within a body after the anchor seed is implanted.

76. The device of claim 75, wherein each radioactive seed includes first and second longitudinal ends, and wherein the at least one protrusion extends from at least one of the longitudinal ends.

77. The device of claim 75, wherein each radioactive seed includes first and second longitudinal ends, and wherein the at least one protrusion is located between the longitudinal ends.

78. The device of claim 75, wherein the polymeric material is bio-absorbable.

79. A strand for use in brachytherapy, comprising:

an elongate unitary member of bio-absorbable material; and

a plurality of radioactive sources spaced apart from one another and encapsulated within the unitary member,

wherein an outer surface of the elongate unitary member includes a plurality of protrusions to reduce a tendency of the strand to migrate and rotate within a patient'"'"'s body after implantation.

80. The strand of claim 79, wherein the protrusions are made from the same bio-absorbable material as the elongate unitary member.

81. The strand of claim 79, wherein the protrusions are made from a bio-compatible material that is not bio-absorbable.

82. The strand of claim 79, wherein at least one of the protrusions comprises an anchor mechanism that extends from a longitudinal end of the elongate unitary member.

83. The strand of claim 79, wherein each radioactive source comprises a radioactive seed that includes radioactive material contained within a metallic housing, and wherein the bio-absorbable material is molded to encapsulate the metallic housing of each seed.

84. The strand of claim 79, wherein the radioactive sources comprise a radioactive rods or coils.

85. The strand of claim 79, wherein at least one of the protrusions extends at least 0.002 inches beyond portions of the bio-absorbable material where there is not a protrusion.

86. A strand for use in brachytherapy, comprising:

an elongate unitary member of plastic material; and

a plurality of radioactive sources spaced apart from one another and encapsulated with the plastic material;

wherein a plurality of protrusions extend from an outer surface of the elongate member of plastic material, the protrusions to reduce a tendency of the strand to migrate and rotate within a patient'"'"'s body after implantation.

87. The strand of claim 86, wherein at least one of the protrusions extends at least 0.002 inches beyond portions of the material where there is not a protrusion

88. A strand for use in brachytherapy, comprising:

an elongate unitary member of bio-absorbable material including first and second longitudinal ends;

a plurality of radioactive sources spaced apart from one another and encapsulated with the bio-absorbable material; and

an anchor mechanism that extends from at least one of the first and second longitudinal ends of the elongate member to reduce a tendency of the strand to migrate and rotate within a patient'"'"'s body after implantation.

89. The strand of claim 88, wherein the anchor mechanism is formed from the bio-absorbable material.

90. The stand of claim 88, wherein the bio-absorbable material is polymeric.

91. The strand of claim 88, wherein a void is formed between the anchor mechanism and a portion of the bio-absorbable material that encapsulates the radioactive source that is closest to the anchor mechanism, the void to allow patient tissue to enter the void after implantation.

92. A spacer for use in separating implanted radioactive sources from one another,

wherein the spacer includes first and second longitudinal ends and a portion therebetween,

wherein the spacer is configured to be placed between a pair of radioactive sources such that one of the radioactive sources is adjacent the first longitudinal end of the spacer, and the other one of the radioactive sources is adjacent the second longitudinal end of the spacer, and

wherein at least one protrusion extends from the portion of the spacer, between the first and second longitudinal ends, to reduce a tendency for the spacer to migrate and rotate within a patient'"'"'s body after implantation.

93. The spacer of claim 92, wherein the spacer is made of a bio-absorbable material.

94. The spacer of claim 92, wherein the spacer includes a non-bio-absorbable body that is at least partially encapsulated with a polymeric material that is molded around the body, wherein an outer surface of the encapsulating polymeric material includes the at least one protrusion.