Drug – bio-affecting and body treating compositions – Radionuclide or intended radionuclide containing; adjuvant... – Coated – impregnated – or colloidal particulate
Reexamination Certificate
1998-11-13
2002-05-21
Dudash, Diana (Department: 1619)
Drug, bio-affecting and body treating compositions
Radionuclide or intended radionuclide containing; adjuvant...
Coated, impregnated, or colloidal particulate
C424S001290, C424S001330, C424S001110, C600S001000, C600S002000, C600S003000, C600S008000
Reexamination Certificate
active
06391279
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to radioactive seeds for brachytherapy and a process for making the same. In particular, the present invention relates to radioactive seeds containing either Pd-103 or I-125 located within a cured resin matrix.
BACKGROUND OF THE INVENTION
Brachytherapy refers to the treatment of diseases, especially the treatment of tumors, including malignant tumors such as cancer, with radiation. Radioactive seeds (a.k.a., radioactive pellets, interstitial implants and discrete brachytherapy sources) are a well known means of delivering a radioactive source to a target. A variety of radioactive sources have been used, all with the goal of irradiating diseased tissue and minimizing irradiation of healthy tissue. Consequently, it is desirable to have a source which provides uniform radiation and which can be detected after implantation (i.e., X-ray). Thus, radioactive seeds often contain some type of X-ray marker to ensure their proper placement.
A number of different radioactive seeds are known to those of skill in the art. For example, U.S. Pat. No. 3,351,049 describes a radioactive seed which has a sealed container with a cavity (e.g., stainless steel or titanium), an isotope within the cavity (e.g., I-125), and a carrier for maintaining the isotope's uniform distribution within the cavity, and optionally, an X-ray visualizable means (e.g, gold and tungsten. U.S. Pat. No. 4,323,055 describes an improved seed wherein a carrier body which is an X-ray detectable silver or silver-coated rod coated with radioactive iodine is used.
U.S. Pat. No. 4,702,228 describes a seed for brachytherapy containing a Pd pellet. The Pd is enriched in Pd-102 so that the seed may be activated (i.e., Pd-103 is formed) by exposure to neutron flux. U.S. Pat. No. 5,405,309 depicts a seed containing an electroconductive support pellet, Pd-103 (carrier free) plated on the pellet and a biocompatible shell encapsulating the electroplated pellet. In order to overcome some of the problems of attaching a radioactive source to a carrier, U.S. Pat. No. 5,163,896 uses a metallic substrate having a radioactive-absorbing coating material containing polyamino acids (e.g., polytyrosine).
A number of problems exist with two of the currently used currently used radioactive sources Pd-103 and I-125. Sources like Pd-103 can be difficult to uniformly apply to a carrier. For example, when Pd-103 is plated onto a carrier, Pd-102 is used to enhance the plating process. Unfortunately, the presence of Pd-102 can attenuate a significant portion of the gamma rays emitted from Pd-103. Seeds containing either Pd103 or I-125 are generally prepared by coating the source onto a carrier and then manually assembling the seed. Such manual assembly can lead to numerous errors when a X-ray marker needs to be included. In addition, there is always an issue of operator exposure when a radioactive source is being handled.
Due to the importance of brachytherapy and the numerous inefficiences of current radioactive seed technology, it is thus desirable to find new radioactive seeds and reproducible ways of manufacturing radioactive seeds which provide uniform output of seeds.
SUMMARY OF THE INVENTION
Accordingly, one object of the present invention is to provide a novel radioactive seed.
It is another object of the present invention is to provide a process for manufacturing radioactive seeds.
These and other objects, which will become apparent during the following detailed description, have been achieved by the inventors discovery that a cured mixture of a resin and a radionuclide can be conveniently and reproducibly prepared and used for brachytherapy.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[1] In a first embodiment, the present invention provides a novel seed, comprising:
(a) a biocompatible capsule having a hollow core; and,
(b) a first length of a cured mixture disposed within the hollow core, the cured mixture, comprising:
(bi) a resin, and
(bii) a radionuclide suitable for brachytherapy.
[2] In preferred embodiment, the seed further comprises:
(c) a second length of a cured mixture disposed within the hollow core; and,
(d) a X-ray marker disposed within the hollow core, the X-ray maker being located between the first and second lengths of cured mixture.
[3] In a more preferred embodiment, the radionuclide is selected from Pd-103 and I-125.
[4] In an even more preferred embodiment, the radionuclide is Pd-103.
[5] In an even more preferred embodiment, the radionuclide is I-125.
[6] In another more preferred embodiment, the biocompatible capsule is comprised of a material selected from the group: titanium, aluminum, magnesium, and plastic.
[7] In an even more preferred embodiment, the biocompatible capsule is comprised of titanium.
[8] In another more preferred embodiment, the resin is selected from epoxy, polyurethane, polyimide, and polyamide.
[9] In another more preferred embodiment, each length of cured mixture is surrounded by plastic tubing.
[10] In another more preferred embodiment, the X-ray marker is selected from silver, gold, tungsten, and lead.
[11] In a second embodiment, the present invention provides a novel process for manufacturing a seed, comprising:
(1) blending a radionuclide suitable for brachytherapy and a resin to form a mixture;
(2) transfering the mixture into plastic tubing;
(3) curing the mixture;
(4) cutting the tubing and cured mixture to a suitable length;
(5) placing a cut length of cured mixture into a biocompatible capsule; and,
(6) sealing the capsule.
[12] In another preferred embodiment, the radionuclide is selected from Pd-103 and I-125.
[13] In another preferred embodiment, the resin is selected from epoxy, polyurethane, polyimide, and polyamide.
[14] In another preferred embodiment, the biocompatible capsule is comprised of a material selected from the group: titanium, aluminum, magnesium, and plastic.
[15] In another more preferred embodiment, the biocompatible capsule is comprised of titanium.
[16] In another preferred embodiment, the tubing is selected from polyethylene, polypropylene, polyvinyl chloride, polyvinyl acetate, polyimide, polyamide, polytetrafluoroethylene and polyvinylidene chloride.
[17] In another preferred embodiment, step (4), comprises:
(4i) removing the tubing from the cured mixture; and,
(4ii) cutting the cured mixture to a suitable length.
[18] In another preferred embodiment, step (5), comprises:
(5i) placing a first cut length of cured mixture into a biocompatible capsule;
(5ii) placing a X-ray marker into the capsule; and,
(5iii) placing a second cut length of cured mixture into the capsule, whereby the X-ray marker is positioned between the first and second lengths of cured mixture.
[19] In another preferred embodiment, the X-ray marker is selected from silver, gold, tungsten, and lead.
[20] In a third embodiment, the present invention provides a novel seed, comprising:
(a) a first biocompatible polymer in the shape of a seed; and,
(b) a radionuclide suitable for brachytherapy, the radionuclide being present within the first biocompatible polymer.
[21] In another preferred embodiment, the seed further comprises
(c) a X-ray marker disposed within the first biocompatible polymer material.
[22] In another preferred embodiment, the seed further comprises:
(d) a second biocompatible polymer encapsulating the first biocompatible polymer.
[23] In a more preferred embodiment, the radionuclide is selected from Pd-103 and I-125.
[24] In another more preferred embodiment, the X-ray marker is selected from silver, gold, tungsten, and lead.
[25] In another more preferred embodiment, the first and second biocompatible polymers are independently selected from polyimide, polyamide, epoxy and polyisocyanurate.
[26] In a fourth embodiment, the present invention provides a novel proce
Olewine Keith R.
Singh Prahlad R.
Tercho Gerald P.
Wentz Jack N.
Bristol-Myers Squibb Pharma Company
Dolan Peter L.
Dudash Diana
O'Brien Maureen P.
Sharareh Shahnam
LandOfFree
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