Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS3351049 A
Publication typeGrant
Publication dateNov 7, 1967
Filing dateApr 12, 1965
Priority dateApr 12, 1965
Publication numberUS 3351049 A, US 3351049A, US-A-3351049, US3351049 A, US3351049A
InventorsLawrence Donald C
Original AssigneeHazleton Nuclear Science Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Therapeutic metal seed containing within a radioactive isotope disposed on a carrier and method of manufacture
US 3351049 A
Images(1)
Previous page
Next page
Description  (OCR text may contain errors)

3,351,049 IVE ISOTOPE TURE N V- 7. 9 D. c. LAWRENCE THERAPEUTIC METAL SEED CONTAINING WITHIN A RADIOACT DISPOSED ON A CARRIER AND METHOD OF MANUFAC Filed April 12, 1965 Fig.2

INVENTOR.

Q m 2 C mfl O m Y B Fig.4

Attorneys United States Patent This application is a continuation-in-part of my copending application Serial No. 325,332, filed November 21, 1963, now abandoned.

This invention relates to therapeuti radiology. More particularly, it relates to a radioactive X-ray emitting source usually referred to as a seed and a method of manufacture therefor.

Radiation therapy refers to the treatment of diseases especially the treatment of tumors including malignant tumors, such as cancer, with radiation. In radiation therapy, it is desired to destroy the malignant tissue without causing excessive radiation damage to nearby healthy and possibly vital tissues which, because of their proximity, are likely to receive considerable irradiation.

Special methods have been developed for preferentially irradiating deep seated diseased tissue. These include the use of high energy X-ray beams together with cross-fire and rotational techniques by which a radiation pattern is created which has a maximum value localized at the site of the diseased tissue. Even so, some absorption and damage inevitably occurs to the normal tissues through which the radiation beam must pass in order to arrive at such deep seated tissue.

Another method of excellent potential for limiting the region of irradiation utilizes radioactive substances in the form of seeds which are implanted at the region to be irradiated. Radioactive materials which have been used to make such seeds have included radon, radium, and radiogold. Seeds constructed of these materials have been made by methods developed over the last several decades and have been used quite beneficially in therapy. However, the seeds heretofore employed have had several disadvantages which have reduced their use.

The high energy penetrating power of the characteristic radiations of these materials of prior use makes it very diflicult to adequately shield the administering personnel from these emitted radiations. For example, the surgeon who makes the implant of the seed can receive a considerable dosage in his hands or other parts of his body. While under treatment, the patient must be segregated and shielded from others which causes additional expense and inconvenience. Another disadvantage results from the irradiation of the patients healthy tissues outside of the diseased area being treated due to the excessive penetrating power of the radiation produced by the hitherto employed radiation source materials. The characteristic half-lives of some of these prior art materials are rather long, and thus it is necessary that such seeds be removed after the predetermined radiation dosage has been administered to prevent overirradiation and attendant ill efiects. As this usually requires an additional surgical pr cedure, another undesired irradiation of the surgeons hands will occur. When treating inoperable malignancies and especially those which affect vital organs, the removal of such seeds may even be impossible, necessitating, in the case of materials of long half life, separation of the patient from others, including his family, for a long period of time.

Therefore, it is an object of the resent invention to provide an improved therapeutic radioactive source and method of manufacture therefor which will overcome the above named disadvantages.

Another object of the invention is to provide a source and method of manufacture of the above character in which a therapeutic dosage of the desired radioactive material is confined in an encapsulating medium which prevents any migration of leakage from such encapsulation.

Another object of the invention is to provide a improved source and method of manufacture therefor of the above character which will last sufliciently Ion-g to provide a desired amount of radiation and yet not so long as to require removal by surgery after it has performed its function.

Another object of the invention is to provide a source and method of manufacture therefor of the above character in which a therapeutic amount of the appropriate radioactive isotope is encapsulated.

Another object of the invention is to provide a source and method of manufacture therefor of the above character in which the encapsulating medium is nontoxic, corrosion resistant and compatible with biological fluids so that the seed can be left indefinitely in place.

Another object of the invention is to provide a source and method of manufacture therefor of the above character in which the encapsulating medium represents a uniform shadowing effect with respect to the radiations emanated therefrom so that the value of the radiation pattern about the seed is substantially uniform.

Another object of the invention is to provide a source and method of manufacture therefor of the above character in which the radioactive material is uniformly distributed throughout the seed interior so as to prevent localization of the radioactive material and consequent undesirable point source effects.

Another object of the invention is to provide a source and method of manufacture therefor of the above character which can be detected by standard X-ray techniques so that the position of each source can be plotted and the dosage distribution computed.

Another object of the invention is to provide a source and method of manufacture therefor of the above character which retains the substantially uniform radiation pattern thereabout.

Other objects and features of the invention will be ap' parent from the following description and from the accompanying drawings of which:

FIGURE 1 shows a greatly enlarged view of a radioactive source made in accordance with the present invention with portions thereof partially broken away.

FIGURE 2 is a greatly enlarged view of a radioactive source of another embodiment of the invention with the portions thereof partially broken away.

FIGURE 3 is an enlarged view of another embodiment of the invention and showing, in particular, ball means for making the source X-ray detectable.

FIGURE 4 shows a greatly enlarged view of yet another radioactive source made in accordance with the present invention and showing wire means for making the radioactive source X-ray detectable.

This invention is predicated upon the observation that there is a class of radioactive isotopes which characteristically emit a radiation principally limited to low energy X-rays and which have half-lives which are appropriate for obtaining optimum benefits of radiation therapy with seeds while avoiding disadvantages of prior radiation source materials. These isotopes are unique in that their half-lives are sutficiently short that they decay predictably to a negligible output level and therefore can be left permanently and indefinitely implanted within the biological specimen treated. Yet, the radiation energy output intensity and half-lives are sufficiently long to deliver a radiation exposure over an ideal period of time for the optimal therapeutic effect. Thus, the radiation exposure lasts long enough to provide the desired amount of irradiation and yet not so long as to require that the seed be removed by surgery after it has performed its function.

Further, the characteristic radiations of such isotopes are essentially free of alpha and beta emissions, greater than 95% of the radiation being low energy X-rays of energy less than 100 thousand electron volts (hereinafter kev.). Thus, the tissue can be effectively treated while at the same time such radiations can be easily and completely shielded by a relatively thin layer of dense, high-atomic-number material.

The preferred isotopes for use with the invention have radiation characteristics which satisfy the following criteria: a half-life in the range of about 5 to 100 days and preferably about 8 to 80 days. The preferred isotopes are selected with a radiation energy in the soft-X-ray region from about 20 to 100 kev. Preferably, the radiation energy has a value of about 30 kev. Soft X-rays of the above limited energies are easily shielded by thin layers of gold, silver, etc.,"and yet have a reasonable range in soft tissue, the half-value layer being about 2 centimeters. Radioisotopes with half-lives of less than 5 days are generally too short to permit practical processing of the radioisotopes for fabrication and use. Radioisotopes having halflives longer than 100 days emit significant radiation for years and therefore would necessitate removal.

Examples of such suitable isotopes are the monoenergetic X-ray emitting isotopes iodine-125 and cesium- 131. These isotopes have characteristic radiations chiefly consisting of approximately 30 kev. energy X-rays and they also possess half-lives of about 60 and 10 days, respectively. Another isotope example is the isotope palladium-103 having characteristic radiation of about 20 kev. energy and a half-life of about 17 days.

Unfortunately, radioactive iodine has not heretofore been usable for localized treatment of diseased tissue except in the treatment of thyroid tissue, since when iodine is introduced into the body, it tends to concentrate almost entirely in that gland. Consequently, treatment of tissues in other parts of the body with radioactive iodine has not been possible. Similarly, in the case of cesium-131, this isotope has not been used due to the 'fact that it typically distributes uniformly throughout the body and is not long retained in effective concentrations at the location to be treated.

The radioactive seed device of the invention is characterized in that the selected radioisotope is encapsulated in such a manner that it cannot migrate through the encapsulating medium, thereby preventing escape and distribution of the radioisotope throughout the body and possible assimilation and concentration of it in healthy tissues, while, at the same time, permitting the soft X-rays to pass through the capsule wall. Thus, the present invention is able to utilize to advantage the ideal properties of this particular class of radioactive isotopes (i.e. an optimum half-life and characteristic radiation energy) so that advantage can be made of the absorption characteristics of soft X-rays, and that the radiation level is sufiiciently high for a period of time adequate to destroy the diseased tissue and yet the irradiation period is sufficiently short so that the effective exposure terminates predictably decaying away after that tissue is destroyed. Thus, the seed need not be surgically removed from the body but may be left in place indefinitely.

More specifically, there is shown in the accompanying drawing a radioactive seed 10 constructed according to the present invention. The seed 10 comprises a therapeutic amount of a selected X-ray emanating radioisotope 11 appropriately distributed on a carrier body 12 disposed interiorly of a tubular container 13. The container is sealed at its ends 14 and 15 and serves to isolate the radioisotope from physical or chemical interchange between body fluids and the interior of the container while at the same time permitting the radiation to pass through the walls of the container. The selected radioisotope is preferably uniformly distributed along the carrier body 12 to avoid having a point source and to maintain a permanent distribution of the radioactive isotope in a fixed bed throughout the extent of the seed. This configuration assures the optimum dose distribution and the best therapeutic effect. In the case of the palladium-l03 isotope, the distribution of the radioisotope can take the form of a uniform laminar distribution along the carrier body and within the capsule.

As shown in the drawing, the container 13 is preferably designed for implantation as by perforate penetration or injection, e.g., by hypodermic needle or similar device especially designed therefor. As such, the container 13 is preferably constructed in an elongated outside shape, having a relatively narrow outside diameter of from about .5 to 1 millimeter, and about 5 millimeters in length. The interior of the container 13 includes a cavity for receiving the carrier body 12, as hereinafter described. For permanent implantation, as by hypodermic injection, the outside diameter of the seed is constructed about 0.75 millimeter and is thus small enough to pass through a hypodermic needle. For permanent implantation, the seed is constructed approximately 4 mm. long so that it will have a minimal movement in tissue and will not migrate from the area to be treated.

It will be understood that some absorption of the easily attenuated radiation by the wall of the container 13 occurs and that such absorption tends to diminish the amount of radiation useful for irradiating the tissue to be treated. Accordingly, an allowance in the dosage amount is made for such absorption. There is, in any event, a balance between sufficient mechanical strength of the container and the minimum absorption characteristics of the wall which must be obtained for optimum results. I have found that the capsule material should be selected from low-atomic-number materials, preferably of atomic number lying in the range of 4-28. The material must be corrosion resistant, compatible with body tissue and nontoxic, or be provided with a coating possessing these properties. By utilizing low-atomic-number material, absorption is held to a satisfactory low level, consistent with a wall thickness sufficient for structural integrity.

In the embodiment shown in FIGURE 1, the container 13 is constructed of the low atomic numbered metal such as stainless steel alloy or titanium. The stainless steel alloy has been found to have several advantages in that it can be sealed to avoid any migration of contents and it is corrosion resistant, compatible, an nontoxic in use and has a sufficiently low atomic number so that it does not unduly absorb the soft X-rays. The attenuation of stainless steel is about 15% per thousandths of an inch for which additional radioisotope is added to compensate for absorption losses in the container walls. The optimum thickness of stainless steel Wall is in the range of .0005- .003 of an inch. A preferred thickness is about .002 of an inch which represents the best compromise between strength and attenuation losses.

Titanium, having a lower atomic number and higher strength to weight ratio than stainless steel, is exceptionally corrosion resistant and is equally satisfactory from the standpoint of compatibility and nontoxicity in the intended use. Titanium should be selected as a rather pure alloy to assure good working characteristics. The wall thickness of the titanium may vary from .001 of an inch to .005 of an inch, the attenuation being about 5% per thousandths of an inch. An optimum value of wall thickness is approximately .002 of an inch. Titanium has several advantages over stainless steel as a container material. It has high strength to weight ratio, about one-third the attenuation, and it can be sealed by various simple techniques, such as cold compression bonding.

atomic number, such as gold or platinum were used, the

It will be noted that if a metal having a relatively high wall thickness of the container would have to be so small for a source containing a given amount of radioisotope and having the same strength, that the physical strength of the source would be impaired. Otherwise, the amount of radioisotope would have to be increased so much that cost considerations would prevent its use. High atomic numbered materials may be useful, however, as plating over a toxic metal of a low atomic number, without absorbing too great an amount of the radiation. Therefore, to use a low atomic numbered material, such asberyllium, requires that it be supplied with an outer coating of nontoxic, corrosion resistant material such as gold. As to absorption, a container constructed of beryllium can have a wall thickness as high as .035 inch.

The carrier body 12 is provided for collecting, concentrating and supporting the radioisotope and for maintaining it in an appropriately distributed form throughout the container. The carrier body 12 may be formed in a shape generally conforming to that of the interior of the container in which it is to be disposed so that it will not shift in the container. Thus, when disposed in a cylindrical container, the carrier body 12 extends in a cylindrical form substantially throughout the interior thereof and has a diameter approximating that of the inside diameter of the container 13. The carrier body 12 is constructed of any suitable material which will chemically or physically capture the selected radioisotope to thereby maintain a uniform distribution of the isotope in a fixed bed. Such material is preferably selected from the materials composed of elements of low-atomic-number so as to minimize internal absorption of the X-ray radiations.

In the preferred method of preparing the seed of the present invention, the body 12 of selected carrier material is impregnated with the appropriate radioactive isotope at a level suflicient to make up the therapeutic dosage, making allowance for absorption by the encapsulating material. After the carrier body 12 is impregnated, it is placed within the container 11 which is then sealed. The seal of the container must prevent migration of the radioisotope and must not possess undesirable radiation shielding properties which may result from the geometrical configuration of the end. Such undesirable properties causes a shadow effect in the radiation pattern at the region near the ends of the tube.

In accordance with the present invention, the ends 14 and 15 of the container are closed and sealed. For a metallic container 13, this can be accomplished conveniently by closing over the end of the container as by swaging it shut with a swage block having an interior configuration corresponding to the desired exterior configuration at the end of the container. After forming, the end of the container is fused, as by welding, into a uniform shell. By this technique, the container is made into a one-piece unitary structure having a substantially uniform wall thickness. The particular method of formation of the end seal differs somewhat depending upon the par: ticular material chosen for the container. In the case of stainless steel and titanium, the end is mechanically deformed, as by swaging or spinning, to generally close .over the end and then is fused by welding. It is also possible for the ends to be formed by intermetallically joining the walls under pressure or by ultrasonic welding.

Specifically, with respect to stainless steel, ends have been fused by capacitor discharge arc welding. This may tend to thicken the end wall of the container in which case the fused portion is easily trimmed down so that the finished container has a uniform wall thickness throughout.

Titanium metal, which should be selected from a relatively pure alloy having good formability and heat treatability characteristics, is sealed by-spinning the end of the tube down to a point as by turning and spinning by well known techniques. After this, the end may be fused by welding to obtain the end wall of uniform thickness.

Referring now to FIGURE 2, there is shown another embodiment of the invention utilizing a combination of low atomic number materials for the container member. Specifically, the radioactive isotope is distributed uniformly along the length of an elongate carrier body member 21 which is placed inside an aluminum alloy tube 22 (such as that designated by 3003) which is closed over and sealed at its ends 23. The aluminum tubing is sealed in an inert overcoating or container of plastic, ceramic, or precious metal, to prevent reaction of the aluminum with the body fluids over long periods of time. Organic plastic material, such as nylon, silicone rubber, polyester resin, or fluorinated hydrocarbons may be used to form the container 24.

The fluorinated hydrocarbon Teflon FEP has been found to be a very suitable material in that it is exceptionally nonreactive and nontoxic in biological tissues and is available as a heat shrinkable and heat sealable tubing of small diameter. The seed, as shown in FIGURE 2, is very easily manufactured. A short length of aluminum tubing is cut off and sealed at one end. The carrier body 21 containing the active materials is disposed in the aluminum tubing which is then formed to close upon itself at the open and sealed end. The sealed tubing 22 is then placed inside .a plastic tubing which is cut and sealed at its ends by heating. For heat shrinkable plastics, the application of heat, as by an air blast torch, causes not only the ends to seal but the Whole shell to shrink about the tubing 22 to make a very neat, smooth source.

As described, the embodiment as shown in FIGURE 2 is suitable for any of the isotopes contemplated and, in particular, for the isotope iodine-125. The seal provided at the ends of the metal tubing 22 effectively acts to prevent any migration of the iodide out of the capsule.

However, it will be understood that with isotopes such as cesium-131 such seal is not absolutely necessary and the ends of the aluminum tubing may be left open or unsealed. For while a metallic seal is required to prevent migration of 1-125, the plastic seal alone is entirely adequate to contain the Cs131.

The necessary selection of materials of construction of the radioactive seed, according to the present invention, raises a problem which has' not heretofore existed in that the selection requires the use of low-atomic-number materials for surrounding the carrier body. Thus, prior art materials used for other isotopes, such as platinum, iridiurn, gold, and other high atomic number materials are not suitable as an encapsulating medium. In use, it is desirable that the position and number of seeds in the tissue be deter-mined by standard X-ray photographic techniques. That is to say the patient is given an X-ray from which the location of the seeds is plotted. Typically, this information is analyzed by a computer which computes the dose distribution in the tissue being treated. If any cold spots (insufliciently'irradiated areas) are found, they can then be treated by external radiation therapy or other means to greatly improve the chances for destroying the malignancy completely. In the case of the above described X-ray emitting seed, the necessary low atomic number materials of the seeds are not normally visible on an X-ray.

Therefore, there is provided a modified embodiment which incorporates means for blocking the transmission of X-rays to thereby make the seed capable of being detected by X-ray photographic techniques.

Referring specifically to FIGURES 3 and 4, there are shown two embodiments utilizing suchmeans. In FIG- URE 3, there is provided a small ball 26 which is positioned midway in the seed, the carrier body within the seed being formed into portions 27a and b. The ball 26 is constructed of a dense, high-atomic-number material, such as gold, tungsten, etc. The ball 26 is constructed to have a diameter of approximately .002 to .020 of an inch in order to render an image in the X-ray. The carrier bodies 27a and b and ball 26 are housed in a container 28 in the manner heretofore described in connection with the embodiment of FIGURE 1.

Referring specifically to FIGURE 4, there is shown another embodiment utilizing a wire 31 located centrally at the axis of symmetry of the carrier body 32 which is disposed in the low atomic numbered material container 33 in the manner previously described with respect to the embodiment of FIGURE 1. The wire is made of a high atomic number dense material, such as gold, tungsten, etc., and is about .002 to .005 inch in diameter. Tungsten is a particularly suitable material in that its absorption for X-rays of the energy commonly employed to take X-ray photographs is somewhat higher than its absorption of the lower energy X-rays which are emitted by the radioactive isotopes utilized in this invention.

The geometrical disposition of these high atomic numbered materials within the container is especially important in view of their inherent absorption of the low energy X-rays which are provided by the radioisotope in the seed. If large amounts of such high atomic number and dense material were located about the seed, it would severely attenuate radiation therefrom and materially increase the amount of the total radioisotope required for a given strength, making for very inefficient utilization of the radioactivity. As is easily seen in the embodiment of FIGURES 3 and 4, the primary portion of the radiation emanated from the radioisotope can pass out of the seed without encountering these high atomic numbered materials used for rendering the seed X-ray detectable. Furthermore, the location of the high atomic number material should be such as to permit as uniform a radiation pattern as possible from the seed. In this connection, the ball 26 of FIGURE 3 presents some shielding effects about the midsection of the seed, but this shielding appears to be tolerably small.

The following examples are illustrative of the practice of the invention:

IODINE125 A nylon filament 82 mm. long was placed in an aqueous 'bath of 25 millicuries of carrier free I-125. The pH was adjusted to a pH higher than seven by the addition of NaOH, and suflicient NaHSO added to assure that essentially all the iodine-125 was in the iodide oxidation state. The pH was then adjusted to acidic (about pH 3) by the addition of sulfuric acid, sodium nitrite (NaNO was then added to oxidize the iodide to free iodine (I Due to the relative insolubility of free iodine in water and the afiinity of the nylon organic for free iodine, substantially all of the free iodine selectively entered the nylon filament and was removed from the bath. The filament was then taken from the bath and dried and cut into lengths of about 3 /2 mm. The filament lengths were mounted into stainless steel tubular containers. Each container was about 4 mm. long and had an outside diameter of approximately .025 inch and was previously sealed at one end. The containers were then sealed at the other end by being shaped and fused shut in the manner previously described.

CESIUM131 Cesium-131 is separated from the parent barium-131 (which may be produced by neutron irradiation of barium-l30) by selective ion exchange in a column containing [ammonium phosphomolybdate (NH 3 [PMo O (AMP) together with asbestos. Afterwards, the purified cesium- 131 is eluted from the AMP and formed into a bath.

Suitable carrier bodies comprise extruded rods, formed of cellulose acetate binder, acetone and AMP. These rods are used as carrier bodies for absorbing and carrying the predetermined dosage level of cesium-131 available in the bath. The bath is made at least slightly acidic and the rods are placed therein. The preferential affinity of the AMP in the rod absorbs the cesium out of the bath and after which the rods are removed from the bath, dried and sealed with a plastic sealer, such as acrylic plastic, for easier handling. The rods are then encapsulated in suitable containers, such as stainless steel or plastic covered aluminum containers previously described.

PALLADIUM-103 Palladium strongly self-absorbs soft X-rays. To prevent this undesirable circumstance, a thin layer of the radioactive palladium-103 (preferably carrier free) is plated on a plastic rod (nylon) approximately 3 /2 mm. long to a strength of a few millicuries. The rod is then encapsulated in plastic covered (nylon or fluorinated hydrocarbon) aluminum containers as in FIGURE 2. Since the characteristic radiation of the palladium-103 is about 20 kev., an appreciable amount would be absorbed and attenuated by use of material such as stainless steel, rendering the latter economically impractical as an encapsulating material for this radioisotope. For maximum utilization of palladium-103, the effective atomic number of the materials of construction should be as low as practicable (preferably between 4 and 13). For this purpose, an aluminum-plastic capsule is quite suitable.

It is apparent from the foregoing that there has been provided a new and improved radioactive seed and method of manufacture therefor which can be positioned in the region of the body to be treated, and left there indefinitely. After the desired tissue irradiation has been completed, the selected radioactive materials decay away so that the therapy is automatically and gradually cut off without the need for surgical removal of the seed. The container, according to one embodiment, can be detected in X-ray photographs to thereby enable the location and dose distribution to be determined.

While I have disclosed three specific radioactive materials which are especially suited to this application, there are others such as xenon-133 and ytterbium-169 which can be used if proper precautions are taken. The latter isotopes emit only about 50% characteristic X-ray radiations of the desired type, the remainder being essentially higher energy gamma and beta rays which would require additional shielding.

I claim:

1. A radioactive seed for use in radiation therapy of tissue comprising a sealed container having an elongate cavity therein and constructed with walls of substantially uniform thickness, a therapeutic amount of soft X-ray emanating radioisotope disposed within said cavity, said soft X-ray emanating isotope having a characteristic radiation substantially all of which lies between about 20 kev. and kev. and being essentially free from alpha and beta radiations and higher energy X-ray and gamma radiations, said isotope having a half-life from about 8 to 100 days, and means disposed within said cavity for maintaining said radioisotope in a substantially uniform distribution along the length of said cavity, said last named means being made of a material selected to have low absorption for soft X-rays to thereby minimize internal absorption, said container including walls being made of a metal selected to have a relatively low atomic number to thereby minimize the absorption of soft X-rays while completely containing the isotope, said metal being further selected to be nontoxic and nonsoluble in the tissue being treated.

12. A seed for use in radiation therapy of tissue comprising a sealed container having an elongate cavity therein and constructed with walls of substantially uniform thickness, a carrier body means having dimensions for fitting within said cavity and a therapeutic amount of soft X-ray emanating radioisotope uniformly distributed along said carrier body means, said radioisotope being selected from the group consisting of iodine-125, cesium-131, and palladium-103, said carrier body means serving to physically retain the radioisotope in such uniform distribution, said carrier body means being further selected to have a low absorption for soft X-rays to thereby minimize internal absorption, said container being made of a metal having a relatively low atomic number to minimize absorption of soft X-rays while completely containing the isotope, said metal being selected to be nontoxic and nonsoluble in the tissue to be treated.

3. A radioactive seed as in claim 2 in which said isotope is cesium-131 and in which said carrier body means includes ammonium phosphomolybdate for capturing cesium-131.

4. A radioactive seed as in claim 2 in which said radioisotope is palladium-103, and in which the carrier body means is a plastic rod, the palladium-103 being plated on the plastic rod.

5. A radioactive seed as in claim 1 in which the length of the seed is about four mm. and the lateral crosssectional dimension is small enough to permit injection through a hypodermic needle.

6. A seed as in claim 5 in which the lateral crosssectional dimension of said seed is from about .5 to 1.0 millimeters.

7. A seed as in claim 1 in which said metal selected to have a relatively low atomic number is stainless steel having a thickness from about .0005 inch to .003 inch.

8. A seed as in claim 1 in which said metal selected to have a relatively low atomic number is titanium having a thickness from about .001 inch to .005 inch.

9. A seed as in claim 1 in which said container is constructed of an aluminum alloy overcoated with an inert plastic.

10. A radioactive seed for use in radiation therapy comprising a stainless steel tube having its ends fused, and carrier body means formed of an organic polymer containing the radioactive iodine isotope I dispersed therealong, said carrier body being disposed axially within said stainless steel tube.

11. A radioactive seed for use in radiation therapy comprising a stainless steel tube of relatively narrow diameter having its ends fused, a nylon filament containing the radioactive iodine isotope I dispersed therealong, said nylon filament being disposed axially within said stainless steel tube.

12. A radioactive seed in accordance with claim 11 wherein said stainless steel tube has a diameter of less than about of an inch and said nylon filament contains about 5 millicuries of said I per centimeter.

13 A radioactive seed for use in radiation therapy as in claim 1 further including means for blocking the transmission of X-rays comprising a mass of a high atomic number element so placed as to make the seed X-ray visualizable while minimizing the absorption of soft X-rays generated within the seed.

14. A radioactive seed as in claim 13 in which said means for blocking the transmission of X-rays comprises an elongate member having a substantially smaller size than said means disposed within the cavity for maintaining the radioisotope in a substantially uniform distribution, said member being disposed longitudinally and centrally within said cavity.

15. A radioactive seed as in claim 13 in which said means for blocking the transmission of X-rays is a solid ball disposed interiorly of the seed.

16. A method for making a therapeutically radioactive seed comprising soaking a nylon carrier body of an organic polymer in a solution containing the radioactive iodine isotope I so that said body contains a thera eutic amount of the I then placing said body axially inside of a stainless steel tube, and fusing the ends of said tube to seal the same.

References Cited UNITED STATES PATENTS 1,494,826 5/1924 Viol 128-12 2,328,105 12/ 1940 Strobino 252478 2,811,471 10/ 1957 Homeyer. 2,814,296 11/1957 Everett. 3,121,041 2/1964 Stern et a1. 16751 OTHER REFERENCES Silicone Digest, vol. 1, No. 1, October 1959.

C & E News, 39 No. 21; Caged Isotopes May Help Fight Cancer, May 22, 1961, p. 40.

Nuclear Science Abstracts, vol. 16, No. 18, abstract No. 8499, 1962, p. 1091.

Nuclear Science Abstracts, vol. 17, No. 18, abstract No. 30012, 1963, p. 3961.

CARL D. QUARFORTH, Primary Examiner. BENJAMIN R. PADGETT, Examiner. S. J. LECHERT, JR., Assistant Examiner.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1494826 *Sep 29, 1920May 20, 1924Standard Chemical CompanyRadium applicator
US2328105 *Dec 28, 1940Aug 31, 1943Strobino Louis JX-ray shield
US2811471 *May 10, 1954Oct 29, 1957Connecticut Hard Rubber CoPolytrifluorochloroethylene-coated aluminum
US2814296 *Apr 11, 1955Nov 26, 1957S & R J Everett & Company LtdSurgical needles
US3121041 *Jul 20, 1960Feb 11, 1964Olin MathiesonCapsule containing a pharmaceutically useful radioactive material
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3663685 *Apr 1, 1968May 16, 1972Minnesota Mining & MfgBiodegradable radioactive particles
US3750653 *Sep 8, 1970Aug 7, 1973School Of Medicine UniversityIrradiators for treating the body
US4323055 *Apr 8, 1980Apr 6, 1982Minnesota Mining And Manufacturing CompanyRadioactive iodine seed
US4398089 *Jan 4, 1972Aug 9, 1983The United States Of America As Represented By The Secretary Of The ArmyPenetration sensing system with radiation-emitting material
US4584991 *Dec 15, 1983Apr 29, 1986Tokita Kenneth MMedical device for applying therapeutic radiation
US4697575 *Nov 21, 1984Oct 6, 1987Henry Ford HospitalDelivery system for interstitial radiation therapy including substantially non-deflecting elongated member
US4702228 *Jan 24, 1985Oct 27, 1987Theragenics CorporationX-ray-emitting interstitial implants
US4733653 *Nov 25, 1985Mar 29, 1988The Ontario Cancer InstituteRadiotherapy apparatus
US4754745 *Jul 7, 1986Jul 5, 1988Horowitz Bruce SConformable sheet material for use in brachytherapy
US4763642 *Apr 7, 1986Aug 16, 1988Horowitz Bruce SIntracavitational brachytherapy
US4784116 *Jul 29, 1987Nov 15, 1988Theragenics CorporationCapsule for interstitial implants
US4815449 *Mar 30, 1987Mar 28, 1989Horowitz Bruce SDelivery system for interstitial radiation therapy including substantially non-deflecting elongated member
US4827493 *Oct 5, 1987May 2, 1989Amersham CorporationRadiographic source
US4861520 *Oct 28, 1988Aug 29, 1989Eric van't HooftCapsule for radioactive source
US4891165 *Jul 28, 1988Jan 2, 1990Best Industries, Inc.Device and method for encapsulating radioactive materials
US4994013 *Jul 28, 1988Feb 19, 1991Best Industries, Inc.Pellet for a radioactive seed
US5163896 *Jan 16, 1991Nov 17, 1992Best Industries, Inc.Used in radiation therapy, metal rod coated with a polyamino acid which absorbs radioactive material
US5405309 *Apr 28, 1993Apr 11, 1995Theragenics CorporationX-ray emitting interstitial implants
US5503614 *Jun 8, 1994Apr 2, 1996Liprie; Samuel F.Flexible source wire for radiation treatment of diseases
US5683345 *Oct 27, 1994Nov 4, 1997Novoste CorporationMethod and apparatus for treating a desired area in the vascular system of a patient
US5713828 *Nov 27, 1995Feb 3, 1998International Brachytherapy S.AHollow-tube brachytherapy device
US5833593 *Nov 9, 1995Nov 10, 1998United States Surgical CorporationFlexible source wire for localized internal irradiation of tissue
US5857956 *Jun 7, 1995Jan 12, 1999United States Surgical CorporationFlexible source wire for localized internal irradiation of tissue
US5899882 *Apr 4, 1996May 4, 1999Novoste CorporationCatheter apparatus for radiation treatment of a desired area in the vascular system of a patient
US5997463 *Mar 26, 1998Dec 7, 1999North American ScientificLaser welded brachytherapy source and method of making the same
US6007475 *Aug 12, 1998Dec 28, 1999Cns Technology, Inc.Radioactive therapeutic seeds
US6060036 *Mar 25, 1998May 9, 2000Implant Sciences CorporationRadioactive seed implants
US6066083 *Nov 27, 1998May 23, 2000Syntheon LlcImplantable brachytherapy device having at least partial deactivation capability
US6080099 *Aug 12, 1998Jun 27, 2000Syntheon, LlcRadioactive therapeutic seeds
US6093141 *Jul 17, 1997Jul 25, 2000Hadasit Medical Research And Development Company Ltd.Stereotactic radiotreatment and prevention
US6099458 *Feb 11, 1999Aug 8, 2000Robertson; RobertEncapsulated low-energy brachytherapy sources
US6132359 *Jan 7, 1999Oct 17, 2000Nycomed Amersham PlcBrachytherapy seeds
US6143431 *May 4, 1998Nov 7, 2000Webster; Brian A.Irradiating target material with protons or deuterons; coating a silver device by emersion plating in an acidified palladium solution
US6163947 *Jul 31, 1997Dec 26, 2000International Brachytherapy S.A.Method of making a hollow-tube brachytherapy device
US6183409Feb 9, 1999Feb 6, 2001Implant Sciences CorporationSoft x-ray emitting radioactive stent
US6200258Aug 10, 1999Mar 13, 2001Syntheon, LlcRadioactive therapeutic seed having selective marker configuration
US6264599Aug 10, 1999Jul 24, 2001Syntheon, LlcRadioactive therapeutic seeds having fixation structure
US6273851May 14, 1999Aug 14, 2001Syntheon, LlcRadioactive therapeutic seeds
US6306074May 4, 1999Oct 23, 2001Novoste CorporationMethod and apparatus for radiation treatment of a desired area in the vascular system of a patient
US6347443Dec 22, 2000Feb 19, 2002International Brachytherapy S.A.Method of making a hollow-tube precursor brachytherapy device
US6391279Nov 13, 1998May 21, 2002Bristol-Myers Squibb Pharma CompanyRadioactive seeds for brachytherapy and a process for making the same
US6395405Nov 9, 1999May 28, 2002Robert E. BuxbaumHydrogen permeable membrane and hydride battery composition
US6400796Jan 30, 2001Jun 4, 2002Implant Sciences CorporationX-ray emitting sources and uses thereof
US6409943Apr 25, 2000Jun 25, 2002The State Of Israel, Atomic Energy CommissionIn-situ-generated solid radiation source based on Tungsten 188 /Rhenium 188 and use thereof
US6440058 *Aug 25, 2000Aug 27, 2002North American Scientific, Inc.Radioactive seeds and method for using same
US6442822 *Oct 12, 1998Sep 3, 2002Interventional Therapies, LlcFlexible source wire for localized internal irradiation of tissue
US6461433Jul 5, 2000Oct 8, 2002International Brachytherapy, S.A.Fluid-jet deposition of radioactive material
US6471631May 22, 2000Oct 29, 2002Syntheon, LlcImplantable radiation therapy device having controllable radiation emission
US6471632May 18, 2001Oct 29, 2002Syntheon, LlcRadioactive therapeutic seeds
US6485405Jul 28, 2000Nov 26, 2002Interventional Therapies, LlcMethod of making a sourcewire with integral capsule
US6485406Oct 21, 1999Nov 26, 2002Eurotope Entwicklungsgesellschaft Fur Istopentechnologien MbhMedical radioactive iodine-125 miniature radiation sources and methods of producing same
US6503185 *Dec 21, 1999Jan 7, 2003Novoste CorporationMethod and apparatus for treating a desired area in the vascular system of a patient
US6503186 *Mar 29, 1999Jan 7, 2003North American Scientific, Inc.Radioactive seed with multiple markers and method for using same
US6505392Apr 11, 1997Jan 14, 2003Interventional Therapies LlcProcess for manufacturing a radioactive source wire for irradiating diseased tissue
US6508754Sep 23, 1998Jan 21, 2003Interventional TherapiesSource wire for radiation treatment
US6576350May 14, 2002Jun 10, 2003Robert E. BuxbaumFor separation and purification of hydrogen gas from a fluid mixture; storage and recycle characteristics
US6589502Nov 27, 1995Jul 8, 2003International Brachytherapy S.A.Radioisotope dispersed in a matrix for brachytherapy
US6638205Nov 17, 2000Oct 28, 2003Mds (Canada) Inc.Radioactive medical device for radiation therapy
US6638207Oct 15, 2002Oct 28, 2003North American Scientific, Inc.Radioactive seed with multiple markers and method for using same
US6666812Oct 28, 2002Dec 23, 2003Syntheon, LlcRadioactive therapeutic seeds
US6669621 *Mar 14, 2001Dec 30, 2003Cordis CorporationMethod and assembly for containing radioactive materials
US6689043 *Nov 5, 1999Feb 10, 2004Amersham PlcProducts and methods for brachytherapy
US6712752Nov 15, 2002Mar 30, 2004Syntheon, LlcRadioactive therapeutic seed having selective marker configuration
US6716156Feb 4, 2002Apr 6, 2004Aea Technology Osa GmbhCapsule seed
US6749553May 16, 2001Jun 15, 2004Theragenics CorporationRadiation delivery devices and methods for their manufacture
US6749554Feb 25, 2000Jun 15, 2004Amersham PlcMedical tools and devices with improved ultrasound visibility
US6773390 *Mar 20, 2002Aug 10, 2004Cordis CorporationRadioactive source ribbon assembly
US6786858Apr 26, 2002Sep 7, 2004Ideamatrix, Inc.Delivery system and method for interstitial radiotherapy using hollow seeds
US6796936Oct 28, 2002Sep 28, 2004Syntheon, LlcImplantable radiation therapy device having controllable radiation emission
US6821242 *Dec 21, 1999Nov 23, 2004Novoste CorporationMethod and apparatus for treating a desired area in the vascular system of a patient
US6876712Dec 6, 1999Apr 5, 2005Interventional Therapies, L.L.C.Radioactive core; conveying through narrow passageway; sealed housing; thin wire for radiation therapy; anticancer agents
US6881183Oct 23, 2003Apr 19, 2005North American Scientific, Inc.Radioactive seed with multiple markers and method for using same
US6905455Nov 1, 2001Jun 14, 2005Medi-Physics, Inc.Radioactive member and method of making
US6986880Jul 7, 2003Jan 17, 2006International Brachytherapy, S.A.For use in radiology; for attachment to catheters
US6997862Jul 15, 2003Feb 14, 2006Ideamatrix, Inc.Delivery system and method for interstitial radiation therapy using seed strands with custom end spacing
US7008368Nov 18, 2003Mar 7, 2006Ideamatrix, Inc.Method for making treatment strands
US7011619Aug 13, 1999Mar 14, 2006Ge Healthcare LimitedApparatus and methods for radiotherapy
US7060020Dec 28, 2001Jun 13, 2006Ideamatrix, Inc.Delivery system and method for interstitial radiation therapy
US7066872 *Apr 11, 2003Jun 27, 2006Best Vascular, Inc.Method and apparatus for treating a desired area in the vascular system of a patient
US7074291Jun 4, 2002Jul 11, 2006Worldwide Medical Technologies, L.L.C.Delivery system and method for interstitial radiation therapy using strands constructed with extruded strand housings
US7083566Apr 12, 2001Aug 1, 2006Ge Healthcare LimitedGrooved brachytherapy sources
US7094198Jun 4, 2002Aug 22, 2006Worldwide Medical Technologies, LlcDelivery system and method for interstitial radiation therapy using seed elements with ends having one of projections and indentations
US7118729Jul 11, 2000Oct 10, 2006Civatech CorporationRadioactive source materials formable into various shapes
US7160238Dec 21, 1999Jan 9, 2007Best Vascular, Inc.Method and apparatus for treating a desired area in the vascular system of a patient
US7172549Mar 29, 2004Feb 6, 2007Slater Charles RRadioactive therapeutic seed having selective marker configuration
US7211039Apr 24, 2006May 1, 2007Worldwide Medical Technologies LlcStrand with end plug
US7244226Nov 10, 2003Jul 17, 2007Worldwide MedicalTechnologies, LLCMethods for making therapeutic elements for implantation into patient tissue
US7252630Nov 18, 2003Aug 7, 2007Worldwide Medical Technologies LlcDelivery for interstitial radiotherapy using hollow seeds
US7316644Aug 5, 2005Jan 8, 2008Isoray Medical, Inc.Method for preparing particles of radioactive powder containing Cesium-131 for use in brachytherapy sources
US7322928Mar 17, 2003Jan 29, 2008Medi-Physics, Inc.Products and methods for brachytherapy
US7407477Mar 27, 2007Aug 5, 2008Worldwide Medical Technologies LlcStrand with end plug
US7410458Nov 12, 2003Aug 12, 2008Isoray Medical, Inc.Brachytherapy implant seeds
US7479261Jun 22, 2005Jan 20, 2009Isoray Medical, Inc.Dissolving neutron-irradiated barium containing Cs-131 in an acid solution; concentrating the solution; contacting with nitric acid, whereby Cs-131 is dissolved and barium initrate is precipitated; separating the solids, which may be stored to allow additional Cs-131 to form; removal of trace Ba
US7497818Mar 26, 2003Mar 3, 2009Terwilliger Richard ADelivery system and method for interstitial radiation therapy
US7510691Feb 27, 2007Mar 31, 2009Isoray Medical, Inc.precipitating the barium as a carbonate solid, whereby the Cs-131 remains dissolved in the first solution; evaporating; subjecting the residue to oxidative treatment to yield a digested residue; purifying the Cs-131
US7517508Jul 25, 2005Apr 14, 2009Isoray Medical, Inc.Method of separating and purifying Yttrium-90 from Strontium-90
US7530941Feb 2, 2004May 12, 2009Best Medical International, Inc.X-ray and gamma ray emitting temporary high dose rate brachytherapy source
US7531150Jul 27, 2005May 12, 2009Isoray Medical, Inc.Method of separating and purifying cesium-131 from barium carbonate
US7547274Apr 5, 2005Jun 16, 2009Medi-Physics, Inc.Radioactive member and method of making
US7588528Aug 24, 2004Sep 15, 2009C. R. Bard, Inc.Brachytherapy apparatus for dispensing medication
US7601113Sep 9, 2003Oct 13, 2009Cianna Medical, Inc.Brachytherapy apparatus and methods of using same
US7625397Sep 18, 2001Dec 1, 2009Ethicon Endo-Surgery, Inc.Methods for defining and marking tissue
US7686756Aug 28, 2007Mar 30, 2010Ciratech OncologyBrachytherapy devices and related methods and computer program products
US7736293 *Jul 22, 2005Jun 15, 2010Biocompatibles Uk LimitedImplants for use in brachytherapy and other radiation therapy that resist migration and rotation
US7736294Oct 28, 2005Jun 15, 2010Biocompatibles Uk LimitedDelivery system and method for interstitial radiation therapy using seed strands with custom end spacing
US7736295Nov 15, 2005Jun 15, 2010Biocompatibles Uk LimitedDelivery system and method for interstitial radiation therapy using custom end spacing
US7874974Oct 28, 2005Jan 25, 2011Biocompatibles Uk LimitedDelivery system and method for interstitial radiation therapy
US7874976Sep 7, 2006Jan 25, 2011Biocompatibles Uk LimitedEchogenic strands and spacers therein
US7878964Sep 7, 2006Feb 1, 2011Biocompatibles Uk LimitedEchogenic spacers and strands
US7922646 *Aug 20, 2004Apr 12, 2011International Brachytherapy, S.A.Plastic brachytherapy sources
US7942803Jan 21, 2010May 17, 2011Biocompatibles Uk LimitedDelivery system and method for interstitial radiation therapy
US7972261Jul 20, 2006Jul 5, 2011Biocompatibles Uk LimitedDevices to resist migration and rotation of implants used in brachytherapy and other radiation therapy
US7985172Apr 27, 2007Jul 26, 2011Biocompatibles Uk LimitedAfter-loader devices and kits
US7988611Nov 3, 2006Aug 2, 2011Biocompatibles Uk LimitedAfter-loader for positioning implants for needle delivery in brachytherapy and other radiation therapy
US8007427Dec 19, 2007Aug 30, 2011Medi-Physics, Inc.Products and methods for brachytherapy
US8021291Jan 21, 2009Sep 20, 2011Biocompatibles Uk LimitedMarkers for use in brachytherapy and other radiation therapy that resist migration and rotation
US8033981Jun 15, 2009Oct 11, 2011Medi-Physics, Inc.Radioactive member and method of making
US8066627Jun 16, 2006Nov 29, 2011Biocompatibles Uk LimitedDelivery system and method for interstitial radiation therapy using strands constructed with extruded strand housings
US8114007Dec 15, 2008Feb 14, 2012Biocompatibles Uk LimitedImplants for use in brachytherapy and other radiation therapy that resist migration and rotation
US8187159Feb 26, 2009May 29, 2012Biocompatibles, UKTherapeutic member including a rail used in brachytherapy and other radiation therapy
US8192345Jan 21, 2009Jun 5, 2012Biocompatibles, UKCartridge for use with brachytherapy applicator
US8349391 *Oct 30, 2006Jan 8, 2013Actinium Pharmaceuticals Inc.Radium target and method for producing it
US8366598 *Aug 18, 2011Feb 5, 2013Biocompatibles Uk LimitedImplants for use in brachytherapy and other radiation therapy that resist migration and rotation
US8470294Jun 25, 2010Jun 25, 2013Microspherix LlcFlexible and/or elastic brachytherapy seed or strand
US8560052Apr 20, 2004Oct 15, 2013Core Oncology, Inc.Echogenic medical device
US8715598Apr 6, 2012May 6, 2014Actinium Pharmaceuticals Inc.Method for the purification of radium from different sources
US20070153954 *Oct 30, 2006Jul 5, 2007Actinium Pharmaceuticals, Inc.Radium target and method for producing it
US20120016176 *Aug 18, 2011Jan 19, 2012Biocompatibles, Inc.Implants for use in brachytherapy and other radiation therapy that resist migration and rotation
USRE29066 *Mar 15, 1974Dec 7, 1976Minnesota Mining And Manufacturing CompanyBiodegradable radioactive particles
DE19850203C1 *Oct 23, 1998May 31, 2000Eurotope EntwicklungsgesellschMedical radioactive iodine-125 miniature source comprises a radioactive carrier matrix enclosed in a corrosion resistant and body-compatible material
EP0037678A1 *Mar 24, 1981Oct 14, 1981Minnesota Mining And Manufacturing CompanyImproved radioactive iodine seed
EP0064860A2 *May 5, 1982Nov 17, 1982Minnesota Mining And Manufacturing CompanyShielding device for radioactive seed
EP0341039A1 *May 3, 1989Nov 8, 1989Triangle Research And Development CorporationTransendoscopic implant capsule
EP0433011A1 *Dec 11, 1990Jun 19, 1991Robert E. FischellIntra-arterial stent with the capability to inhibit intimal hyperplasia
EP1208874A1Nov 17, 2000May 29, 2002MDS Nordion Inc.Radioactive medical device for radiation therapy
EP1232769A1Feb 15, 2001Aug 21, 2002AEA Technology QSA GmbHCapsule seed manufactured with Pd-103
EP1232770A1Mar 20, 2001Aug 21, 2002AEA Technology QSA GmbHRadioactive capsule seed
EP1232771A1Feb 5, 2002Aug 21, 2002AEA Technology QSA GmbHRadioactive capsule seed
EP1282458A2 *May 18, 2001Feb 12, 2003Theragenics CorporationRadiation delivery devices and methods for their manufacture
EP1406693A2 *May 15, 2002Apr 14, 2004University of StellenboschRadiation application method and device
EP1514580A1Apr 12, 2001Mar 16, 2005Amersham plcGrooved brachytherapy sources
EP2462988A1Nov 1, 2002Jun 13, 2012Biocompatibles UK LimitedDelivery system and method for interstitial radiation therapy
WO1986004248A1 *Jan 24, 1986Jul 31, 1986Nuclear Medicine IncX-ray-emitting interstitial implants
WO1990001208A1 *Jul 28, 1989Feb 8, 1990Best Ind IncDevice and method for encapsulating radioactive materials
WO1992003179A1 *Aug 9, 1991Mar 5, 1992Roger R GoodEndocurietherapy
WO1995033512A1 *Jun 8, 1995Dec 14, 1995Samuel F LiprieFlexible source wire for radiation treatment
WO1996015830A1 *Nov 22, 1994May 30, 1996Theragenics CorpX-ray emitting interstitial implants
WO1997019724A1Nov 25, 1996Jun 5, 1997Coniglione RoyHollow-tube brachytherapy device
WO1999039765A2 *Feb 9, 1999Aug 12, 1999Implant Sciences CorpSoft x-ray emitting medical devices
WO1999040970A1Feb 9, 1999Aug 19, 1999Robertson RobertEncapsulated low-energy brachytherapy sources
WO1999048559A1Mar 24, 1999Sep 30, 1999L Michael CutrerLaser welded brachytherapy source and method of making the same
WO1999057731A1 *Apr 20, 1999Nov 11, 1999Mds Nordion IncProduction of palladium-103
WO1999062074A1May 4, 1999Dec 2, 1999Int Brachytherapy S AFluid-jet deposition of radioactive material for brachytherapy devices
WO2000009210A1 *Aug 12, 1999Feb 24, 2000Jahrmarkt Scott LRadioactive seed and method of making
WO2000009211A1 *Aug 12, 1999Feb 24, 2000Jahrmarkt Scott LImproved radioactive therapeutic seeds and methods of making the same
WO2000009212A2Aug 13, 1999Feb 24, 2000Dollimore Lucinda AApparatus and methods for radiotherapy
WO2000032271A1Nov 12, 1999Jun 8, 2000Syntheon LlcImplantable brachytherapy device having at least partial deactivation capability
WO2000051136A1 *Feb 25, 2000Aug 31, 2000Axelsson OskarMedical tools and devices with improved ultrasound visibility
WO2000059571A2 *Apr 5, 2000Oct 12, 2000Imagyn Medical Technologies InBrachytherapy device and method
WO2000064538A1Apr 28, 2000Nov 2, 2000Medi Physics IncProducts and methods for brachytherapy
WO2000076585A1May 24, 2000Dec 21, 2000Nycomed Amersham PlcMethod of coating a metal substrate with a radioactive layer
WO2001087418A1Apr 12, 2001Nov 22, 2001Morten EriksenGrooved brachytherapy sources
WO2002036199A2Nov 1, 2001May 10, 2002Kevin M HelleRadioactive member for use in brachytherapy and method of making
WO2004026111A2Sep 19, 2003Apr 1, 2004Microspherix LlcFlexible and/or elastic brachytherapy seed or strand
WO2004082762A1Mar 17, 2004Sep 30, 2004Kevin HelleProducts and methods for brachytherapy
WO2005002670A1Jul 1, 2004Jan 13, 2005Helle KevinMethods and systems of preparing preloaded needles for brachytherapy
WO2005051454A1 *Sep 8, 2004Jun 9, 2005Isoray IncMethods of fabricating brachytherapy implant seeds
WO2006038958A1 *Jul 27, 2005Apr 13, 2006Isoray Medical IncMethod of separating and purifying cesium-131 from barium carbonate
Classifications
U.S. Classification600/8, 252/478, 252/644
International ClassificationG21F5/00, A61N5/10, A61K51/12, A61M31/00, G21F5/015
Cooperative ClassificationG21F5/015, A61N2005/1024, A61M31/00, A61K51/1282, A61N5/1027
European ClassificationA61K51/12T, A61N5/10B7, G21F5/015, A61M31/00