# US 2006/0224035 A1 · Plastic brachytherapy sources > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2006/0224035 A1 - Document ID: US20060224035A1 - Status: Published application - Kind: A1 - Application number: 10/568,728 - Filed: 2004-08-20 - Published: 2006-10-05 - Earliest claimed: 2003-08-20 - Assignees: International Brachytherapy s.a. - Inventors: John Russell Jr; John Carden Jr; Roy Coniglione; Dominque Moyaux - Web page: https://patentgrep.com/patent/US20060224035A1 ## CPC - A61N 5/1027: {Interstitial radiation therapy} - A61N 2005/1023: {Means for creating a row of seeds, e.g. spacers} - A61N 2005/1024: {Seeds} - A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B) ## Abstract An implantable source (40) of therapeutic radiation for brachytherapy is provided as a sealed, biocompatible capsule (410) of plastic (e.g. polyethylene or PEEK) transparent to the radiation. The capsule contains a radiation source (400) comprising particles of a radioactive isotope (e.g. Pd103, I125, Cs131) in a fluid carrier that is resistant to radiation polymerization but solidifies at elevated temperature. It also has a marker (420), and desirably has a socket (430) which accommodates attaching spacers (660) and makes possible linear strands and planar arrays of the capsules. The spacers may be functional, e.g. heat-generating or medication-releasing. ## Claims ### Claim 1 An implantable source of therapeutic radiation consisting of: a. A sealed, biocompatible capsule made of plastic that is transparent to therapeutic radiation, containing; b. The source of therapeutic radiation consisting of a radioactive isotope substantially uniformly mixed in a fluid carrier that is resistant to radiation polymerization in its fluid phase, but can be induced to solidify by raising its temperature. c. A marker visible by fluoroscope or x-ray film or ultrasound imaging or nuclear magnetic resonance imaging (MRI); d. A radioactive isotope selected from the group: Pd-103, I-125, Cs-131. ### Claim 2 (depends on 1) The implantable source of claim 1 in which the capsule is made of mechanically strong, biocompatible, plastic material such as high density polyethylene or PEEK. ### Claim 3 (depends on 1) The implantable source of claim 1 wherein the capsule is made from medical grade PEEK. ### Claim 4 (depends on 1) The implantable source of claim 1 having a socket or universal joint, or other connecting configuration as an integral part of the capsule, such that it accommodates attaching spacers and makes possible linear strands and planar arrays. ### Claim 5 (depends on 4) A functional unit with 2, 3, 4 or 6 connecting ends which, with capsules of claim 4, make possible linear strands of sources and spacers, and planar arrays of triangular, square, and hexagonal patterns of sources and spacers. ### Claim 6 (depends on 5) A functional unit of claim 5 wherein it controllably releases medicines of several types, including anti-inflammatory drugs, local anesthetics, antibiotics, anti-cancer adjuvants or radiation enhancing drugs. ### Claim 7 A functional unit comprising material that absorbs radio waves to produce heat, making possible an effective means of adding hyperthermia to the radiation treatment of the target organ. ### Claim 8 (depends on 1) A spacer or other attachment to a connection joint on the implantable source of claim 1 that has expandable petals or barbs which hinder the motion through tissue of the attachment and its attached seeds. ### Claim 9 (depends on 1) A functional unit, attached to a capsule of claim 1 by the socket or universal joint, consisting of a malleable plug forming a seal, if required, or a simple retaining element depending on interference with the interior wall on the needle, so that the seed train will only leave the needle as a result of the force applied by the therapist during the implant procedure. The plug can be made with plastic foam such that it is readily imaged with ultrasound so the physician can easily detect the first seed leaving the needle. ### Claim 10 (depends on 1) A plastic carrier of the radioisotope of claim 1b consisting of an epoxy based fluid that is substantially uniformly mixed with the radioisotope to form a fluid that can be jetted through an ink-jet head into the plastic capsule, or into a separate mold, where curing is initiated by heating and it is cured in place in the capsule, or in a separate mold. ### Claim 11 (depends on 10) The plastic carrier of claim 10 where the carrier is the formulation: (percentages are weight percent): (1) Radioactive residue 17% (2) Triethyleneglycoldivinylether 55% (3) epoxy resin 18% (4) Borontrifluoride monoethylamine 2% (5) Propylene carbonate 8% To perform the manufacturing method disclosed herein, the radioactive residue is dissolved in components (2) and (3), while component (4) is dissolved in a portion of the solvent (5). All of the liquids are then combined to form the source material. The source material is then jetted in the proper quantity into the volume of the seed shell that it is to occupy, and the source material is then heated to approximately 190° C., to initiate curing. ### Claim 12 A seed with a plastic carrier consisting of the radioisotope co-mingled with enough non-radioactive isotope such that the resulting carrier is visible with fluoroscope or x-ray film negating the need for a separate marker, but which remains sufficiently transparent to the curative radiation to be a practical therapeutic device. ### Claim 13 (depends on 12) The transmission of therapeutic radiation through the source of claim 12 is between 20% and 80%. ### Claim 14 (depends on 12, 13) The radioisotope of claims 12 and 13 is Pd-103, produced by neutron activation in a nuclear reactor and the remaining stable Pd isotopes, augmented by addition of high specific activity Pd-103 or non-radioactive palladium to adjust the transmission of the carrier. ### Claim 15 (depends on 12, 13) The radioisotope of claims 12 and 13 is I-125, augmented by addition of non-radioactive iodine, or other chemically compatible heavy element, to adjust the transmission of the carrier. ### Claim 16 An implantable source of therapeutic radiation comprising: e. A sealed, biocompatible capsule made of plastic that is transparent to therapeutic radiation, containing; f. The source of therapeutic radiation consisting of a radioactive isotope substantially uniformly mixed in a fluid carrier that is resistant to radiation polymerization in its fluid phase, but can be induced to solidify by raising its temperature. g. A marker visible by fluoroscope or x-ray film or ultrasound imaging or nuclear magnetic resonance imaging (MRI); h. A radioactive isotope selected from the group: Pd-103, I-125, Cs-131. ### Claim 17 (depends on 1) The implantable source of claim 1 in which the capsule is made of mechanically strong, biocompatible, plastic material such as high density polyethylene or PEEK. ### Claim 18 (depends on 1) The implantable source of claim 1 in which the capsule is made from medical grade PEEK. ### Claim 19 (depends on 1) The implantable source of claim 1 which has a socket or universal joint, or other connecting configuration as an integral part of the capsule, such that it accommodates attaching spacers and makes possible linear strands and planar arrays. ### Claim 20 (depends on 4) Biodegradable spacers with 2, 3, 4 or 6 connecting ends which, with capsules of claim 4, make possible linear strands of sources and spacers, and planar arrays of triangular, square, and hexagonal patterns of sources and spacers. ### Claim 21 (depends on 5) The spacers of claim 5 that are designed to controllably release medicines of several types, including anti-inflammatory drugs, local anesthetics, antibiotics, anti-cancer adjuvants or radiation enhancing drugs. ### Claim 22 (depends on 5) The spacers of claim 5 that contain material that absorbs radio waves to produce heat, making possible an effective means of adding hyperthermia to the radiation treatment of the target organ. ### Claim 23 (depends on 1) A spacer or other attachment to a connection joint on the implantable source of claim 1 that has expandable petals or barbs which hinder the motion through tissue of the attachment and its attached seeds. ### Claim 24 (depends on 1) A functional unit, attached to a capsule of claim 1 by the socket or universal joint, consisting of a malleable plug forming a seal, if required, or a simple retaining element depending on interference with the interior wall on the needle, so that the seed train will only leave the needle as a result of the force applied by the therapist during the implant procedure. The plug can be made with plastic foam such that it is readily imaged with ultrasound so the physician can easily detect the first seed leaving the needle. ### Claim 25 (depends on 1) A plastic carrier of the radioisotope of claim 1b consisting of an epoxy based fluid that is substantially uniformly mixed with the radioisotope to form a fluid that can be jetted through an ink-jet head into the plastic capsule, or into a separate mold, where curing is initiated by heating and it is cured in place in the capsule, or in a separate mold. ### Claim 26 (depends on 10) The plastic carrier of claim 10 where the carrier is the formulation: (percentages are weight percent): (1) Radioactive residue 17% (2) Triethyleneglycoldivinylether 55% (3) Cycloaliphatic epoxide resin 18% (4) Borontrifluoride monoethylamine 2% (5) Propylene carbonate 8% To perform the manufacturing method disclosed herein, the radioactive residue is dissolved in components (2) and (3), while component (4) is dissolved in a portion of the solvent (5). All of the liquids are then combined to form the source material. The source material is then jetted in the proper quantity into the volume of the seed shell that it is to occupy, and the source material is then heated to approximately 190° C., to initiate curing. ### Claim 27 A seed with a plastic carrier consisting of the radioisotope co-mingled with enough non-radioactive isotope such that the resulting carrier is visible with fluoroscope or x-ray film negating the need for a separate marker, but which remains sufficiently transparent to the curative radiation to be a practical therapeutic device. ### Claim 28 (depends on 12) The transmission of therapeutic radiation through the source of claim 12 is between 20% and 80%. ### Claim 29 (depends on 1) The device of claim 1 wherein the radioisotope is Pd-103, produced by neutron activation in a nuclear reactor and the remaining stable Pd isotopes, augmented by addition of high specific activity Pd-103 or non-radioactive palladium to adjust the transmission of the carrier. ### Claim 30 (depends on 1) The device of claim 1 wherein the radioisotope is I-125, augmented by addition of non-radioactive iodine, or other chemically compatible heavy element, to adjust the transmission of the carrier. ### Claim 31 A brachytherapy device for use in radiation treatment of an affected tissue region, the brachytherapy device comprising: a sealed hollow outside cylindrical capsule consisting of a biocompatible nonabsorbable polymeric matrix surrounding an inside cylindrical solid radioactive seed composed of a radioactive isotope uniformly mixed with and disbursed throughout a biocompatible nonabsorbable polymeric matrix. ### Claim 32 (depends on 31) A brachytherapy device of claim 31 wherein the radioactive isotope is comprised of a powder selected from the group consisting of Pd-103, I-125 or CS-131. ### Claim 33 (depends on 31) A brachytherapy device of claim 31 wherein the biocompatible nonabsorbable polymeric matrix is selected from the group consisting of high density polyethylene, high density polyaryletheretherketone or medical grade polyaryletheretherketone. ### Claim 34 (depends on 31) A brachytherapy device of claim 31 further comprising a radiographically detectible element for locating the brachytherapy device within the body of a patient. ### Claim 35 (depends on 31) A brachytherapy device of claim 31 further comprising a concave socket joint configuration disposed at either end of the external surface of the outside capsule so as to accommodate at either end, a biodegradable spacing connector comprised of one or more ball joint elements. ### Claim 36 (depends on 35) A brachytherapy device of claim 35 wherein the biodegradable spacing connector is selected from the group of said connectors comprised of one ball joint element, two ball joint elements, three ball joint elements, four ball joint elements or six ball joint elements. ### Claim 37 (depends on 31) A method of making a radioactive seed of the brachytherapy device of claim 31, comprising the steps of: (a) mixing a radioactive isotope dispersed in a solvent, with a biocompatible nonabsorbable polymeric matrix to form a fluid homogenous mixture; (b) injecting said fluid homogenous radioactive mixture through an ink-jet head into a cylindrical mold; (c) heating the mold to cure the fluid homogenous radioactive mixture into a solid radioactive cylindrical form; (d) removing the cured solid radioactive cylindrical form from the mold. ### Claim 38 (depends on 37) The process according to claim 37, wherein the cured solid radioactive cylindrical form is encased within a thin layer of biocompatible nonabsorbable polymeric matrix to seal. ### Claim 39 (depends on 38) The process according to claim 38, wherein a radiographically detectible element is inserted for locating the brachytherapy device within the body of a patient before the mold is heated to cure the fluid homogenous radioactive mixture into a solid radioactive cylindrical form. ### Claim 40 (depends on 38) The process according to claim 38, wherein the radioactive isotope is comprised of a powder selected from the group consisting of Pd-103, I-125 or CS-131. ### Claim 41 (depends on 38) The process according to claim 38 wherein the biocompatible nonabsorbable polymeric matrix is selected from the group consisting of high density polyethylene, high density polyaryletheretherketone or medical grade polyaryletheretherketone.