This invention relates to devices and methods that are used for transferring implants to needles used in brachytherapy, and methods for implanting implants.
Brachytherapy is a general term covering medical treatment which involves placement of radioactive sources near a diseased tissue and can involve the temporary or permanent implantation or insertion of radioactive sources into the body of a patient. The radioactive sources are located in proximity to the area of the body which is being treated. A high dose of radiation can thereby be delivered to the treatment site with relatively low doses of radiation to surrounding or intervening healthy tissue. Exemplary radioactive sources include radioactive seeds, radioactive rods and radioactive coils.
Brachytherapy has been used or proposed for use in the treatment of a variety of conditions, including arthritis and cancer. Exemplary cancers that can be treated using brachytherapy include breast, brain, liver and ovarian cancer and especially prostate cancer in men. For a specific example, treatment for prostate cancer can involve the temporary implantation of radioactive sources (e.g., rods) for a calculated period, followed by the subsequent removal of the radioactive sources. Alternatively, radioactive sources (e.g., seeds) can be permanently implanted in the patient and left to decay to an inert state over a predictable time. The use of temporary or permanent implantation depends on the isotope selected and the duration and intensity of treatment required.
Permanent implants for prostate treatment include radioisotopes with relatively short half lives and lower energies relative to temporary seeds. Exemplary permanently implantable sources include iodine-125, palladium-103 or cesium-131 as the radioisotope. The radioisotope can be encapsulated in a biocompatible casing (e.g., a titanium casing) to form a “seed” which is then implanted. Temporary implants for the treatment of prostate cancer may involve iridium-192 as the radioisotope. For temporary implants, radioactive rods are often used.
Conventional radioactive seeds are typically smooth sealed containers or capsules of a biocompatible material, e.g., titanium or stainless steel, containing a radioisotope within the sealed chamber that permits radiation to exit through the container/chamber walls. Other types of implantable radioactive sources for use in radiotherapy are radioactive rods and radioactive coils, as mentioned above.
Preferably, the implantation of radioactive sources for brachytherapy is carried out using minimally-invasive techniques such as, e.g., techniques involving hollow needles. It is possible to calculate a desired location for each radioactive source which will give the desired radiation dose profile. This can be done using knowledge of the radioisotope content of each source, the dimensions of the source, accurate knowledge of the dimensions of the tissue or tissues in relation to which the source is to be placed, plus knowledge of the position of the tissue relative to a reference point. The dimensions of tissues and organs within the body for use in such dosage calculations can be obtained prior to or during placement of the radioactive sources by using conventional diagnostic imaging techniques including X-ray imaging, magnetic resonance imaging (MRI), computed tomography (CT) imaging, fluoroscopy and ultrasound imaging.
During the placement of the radioactive sources into position, a surgeon can monitor the position of tissues such as the prostate gland using, e.g., ultrasound imaging or fluoroscopy techniques which offer the advantage of low risk and convenience to both patient and surgeon. The surgeon can also monitor the position of the relatively large needle used in implantation procedures using ultrasound or other imaging.
As mentioned above, brachytherapy typically employs hollow needles that are insertable into a patient's body, often with the assistance of a template. A typical template used to guide and/or inform the positioning of hollow needles at a surgical site can provide access to more than one hundred locations. The number of locations can be so numerous that a typical pitch between needle access points can include a pitch of 5 mm.
A hollow needle, as explained above, is used to implant radioactive sources and/or other types of treatment elements into patient tissue at a desired location and to a desired depth. Such treatment elements, which are implantable using the hollow needle, shall be collectively referred to as an implant. Such an implant can be an elongate treatment member, such as a strand that includes a plurality of radioactive sources (e.g., seeds) spaced apart from one another within a bioabsorbable material. Besides a strand, an implant can be another type of treatment member that includes a plurality of radioactive sources spaced apart from one another, such as a member formed of seeds and optional spacers that are frictionally or otherwise connected to one another (e.g., as described in U.S. Pat. Nos. 6,010,446 and 6,450,939, which are incorporated herein by reference). An elongate treatment member may also be made from a hollow tube that includes a plurality of seeds and optional spacers loaded within a bore of the tube, with the tube possibly heat shrunk around the seeds and optional spacers, or the ends of the tube otherwise closed. Alternatively, an implant can be a plurality of loose seeds and loose spacers axially aligned one behind the other. It is also possible that the implant be a single loose radioactive source. Other possibilities also exist, as would be appreciated by one of ordinary skill in the art. For example, an implant can include one or more radioactive rod or coil. An implant can also include one or more seed that has anchoring mechanisms, exemplary details of which are provided in commonly assigned U.S. patent application Ser. No. 11/187,411, entitled “Implants for Use in Brachytherapy and Other Radiation Therapy That Resist Migration and Rotation,” filed Jul. 22, 2005. Alternatively, the implant can be or include some other object and need not be radioactive, e.g. a spacer, a marker, or a thermal seed that gives off heat.
Within the seed drawer 16 is nestled a seed retainer 74 which is adapted to passively enclose the brachytherapy seeds 20 and spacers 18 in the seed channel 64 until the seeds 20 and the spacers 18 are propelled through seed channel 64 and out needle guide 27 by, for example, a stylet 84 (see
In the embodiment illustrated, a locking needle hub 88 of the brachytherapy needle 82 may be attached to the cartridge hub 28 (of the seed cartridge 15) with a turn (e.g., a sixty degree turn), locking the proximal end of brachytherapy needle 82 to the distal end of seed cartridge assembly 11. The stylet 84 may then be used to move spacers 18 and seeds 20 from seed cartridge assembly 11 to a needle cannula 86. Once the spacers 18 and seeds 20 are positioned in the needle cannula 86, the stylet 84 may be removed. The seed cartridge assembly 11 is then disconnected from brachytherapy needle 82, and the stylet 84 is positioned in brachytherapy needle 82 to be used intraoperatively as in a normal brachytherapy procedure utilizing preloaded needles.
Additional details of the exemplary seed cartridge assembly 11 are disclosed in U.S. Pat. No. 6,585,633, which in incorporated herein by reference.
Embodiments of the present invention relate to adaptors that enables a seed cartridge that is configured to be used with a first type of needle having a locking hub to instead be used with a second type of needle having a cylindrical hub. Such a seed cartridge has a hub at its distal end that is configured to attach to the locking hub of the first type of needle. The adaptor includes a proximal portion configured to removably attach (e.g., removably lock or friction fit) to the hub at the distal end of the seed cartridge. The adaptor also includes a distal portion configured to removably attach to the non-locking cylindrical hub of the second type of needle. A central portion of the adaptor connects the proximal and distal portions of the adaptor. A bore extends through the adaptor and allows seeds and optional spacers to be transferred from the seed cartridge into a hollow cannula of the second type of needle.
Embodiments of the present invention are also related methods of implanting seeds and optional spacers into patient tissue using a needle having a cylindrical hub, an adaptor, and a seed cartridge that is configured to be used with a needle having a locking hub.
This summary is not intended to be a complete description of the invention. Other features, aspects, objects and advantages of the invention can be obtained from a review of the specification, the figures, and the claims.
Various types of hollow needles can be used in brachytherapy, examples of which are shown in
When an applicator needle 102a is used in brachytherapy, a sharp stylet (not shown in
Alternatively, an applicator device, such as a MICK® applicator, can be attached to the proximal end of the applicator needle 102a, and the applicator device can be used to dispose loose seeds (and optionally loose spacers) through the needle 102a and into patient tissue. The MICK® applicator is available from Mick Radio-Nuclear Instruments, Inc., Mount Vernon, N.Y. Exemplary details of the MICK® applicator are provided in U.S. Pat. No. 5,860,909.
Referring now to
The seed cartridge assembly 11 described with reference to
Provided in
The central portion 204 and proximal portion 208 of the adaptor 202 can be similar to the needle hub 88 shown in
In accordance with an embodiment, the inner diameter of the distal portion 206 of the adaptor 202 is larger than the inner diameter of the central portion 204 of the adaptor 202, so that the hub 108a of the applicator needle 102a can be accepted therein. In other words, the diameter of the distal portion 206 of the bore 210, designated 220 (which is the portion of the bore 210 within distal portion 206), is larger than the diameter of the central portion of the bore 210 (i.e., the portion of the bore 210 extending through the central portion 204 of the adaptor 204). More specifically, the distal opening of the portion 220 of the bore 210, extending from the distal end 206 towards the central portion 204 of the adaptor 202, has a diameter that is slightly larger than the outer diameter of the hub 108a of the applicator needle 102a, so that the distal portion 220 of the bore 210 is configured to receive, and thereby connect to, the hub 108a of the applicator needle 102a. For example, the diameter of the distal portion 220 of the bore 210 can be 0.099 inches, while the diameter of the main portion of the bore 210, which roughly corresponds to the inner diameter of a hollow needle, can be anywhere from about 0.042 to 0.055 inches. In specific embodiments, the distal portion 220 of the bore 210 has a slight taper from its opening rearward (e.g., an opening diameter of 0.105 inches tapers to 0.985 inches), so that a slight friction fit can be provided between the distal portion 220 of the bore 210 and the hub 108a accepted therein (presuming the outer diameter of the hub 108a is less than 0.105 inches, but greater than 0.985 inches).
Additionally, a depth (d in
As explained above, the adaptor 202 can be used to transfer seeds and optional spacers from the seed cartridge assembly 11 to an applicator needle 102a, after such needle 102a has been inserted into patient tissue. As mentioned above, since the applicator needle 102a has a blunt distal end 106a, a sharp ended stylet would likely be used to assist with insertion of the needle 102a into patient tissue. The sharp stylet would then be removed, and the adaptor 202 can be used to transfer seeds and optional spacers from the seed cartridge assembly 11 to the needle 102a, e.g., using a blunt ended stylet, or alternatively using the same sharp ended stylet if so desired.
More specifically, a distal end of a hollow needle 102a can be implanted into patient tissue at a desired location and to a desired depth, where the needle 102a has a simple cylindrical needle hub 108a at its proximal end (i.e., a hub that does not include threads or a peripheral flange, as was the case with hub 88 and 108b). The adaptor 202 is used to attach the cylindrical needle hub 108a to a distal end of the seed cartridge 15, where as explained above, the hub 28 at the distal end of the seed cartridge is intended to be attached to a threaded or luer locking needle hub (e.g., 88 or 108b). A stylet is inserted into an opening at a proximal end of the seed cartridge assembly 11. Seeds and optional spacers are urged from the seed cartridge assembly 11, through the bore 210 of the adaptor 202, and through a lumen 110a of the hollow needle 102a, to a distal end of the hollow needle 102a. If the stylet is long enough, the hollow needle 108a and the seed cartridge assembly 11 can be retracted, while the stylet is held in place, to thereby deposit the seeds and optional spacers at the desired location and to the depth. Alternatively, if the style is not long enough, the stylet is retracted from the seed cartridge assembly 11, and the seed cartridge assembly 11 (and likely but not necessarily the adaptor 202) is/are removed. Thereafter, a stylet is inserted (e.g., reinserted) into an opening at the proximal end of the hollow needle 108a, and the seeds and optional spacers are urged to a distal end of the hollow needle. The hollow needle is then retracted, while the stylet is held in place, to thereby deposit the seeds and optional spacers at the desired location and to the desired depth.
Methods for using the adaptor 202 shall now be summarized with reference to
Referring to
While the adaptor 202 was described as being used with the exemplary seed cartridge assembly 11 shown and described with reference to
The previous description of the preferred embodiments is provided to enable any person skilled in the art to make or use the embodiments of the present invention. While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.
This application claims priority under 35 U.S.C. 119(e) to U.S. Provisional Patent Application No. 60/914,668, filed Apr. 27, 2007.
Number | Date | Country | |
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60914668 | Apr 2007 | US |