X-ray or gamma ray systems or devices – Source support – Including movable source
Reexamination Certificate
2000-02-11
2001-10-16
Porta, David P. (Department: 2882)
X-ray or gamma ray systems or devices
Source support
Including movable source
C378S193000, C378S197000, C212S901000
Reexamination Certificate
active
06302581
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
Not Applicable
REFERENCE TO MICROFICHE APPENDIX
Not Applicable
BACKGROUND OF THE INVENTION
This invention relates to a miniaturized, programmable radiation source for use in delivering substantially constant or intermittent levels of x-rays to a specified region and, more particularly, to an apparatus for delivering a controlled dose of radiation to a localized volume of tissue, such as a volume of tissue of the human body.
In the field of medicine, radiation is used for diagnostic, therapeutic and palliative treatment of patients. The conventional medical radiation sources used for these treatments include large fixed position machines such as linear accelerators (“LINACs”), smaller transportable radiation delivery machines such as high-dose-rate after loaders, and catheters for low-dose-rate brachytherapy. The current state of the art treatment systems utilize computers to generate complex treatment plans for treating complex geometric volumes.
Typically, these systems apply doses of radiation in order to inhibit the growth of new tissue because it is known that radiation affects dividing cells more than the mature cells found in non-growing tissue. Thus, the regrowth of cancerous tissue in the site of an excised tumor can be treated with radiation to prevent the recurrence of cancer. Alternatively, radiation can be applied to other areas of the body to inhibit tissue growth, for example the growth of new blood vessels inside the eye that can cause macular degeneration.
Conventional radiation treatments systems, such as the LINAC used for medical treatment, utilize a high power remote radiation source and direct a beam of radiation at a target area, such as tumor inside the body of a patient. This type of treatment is referred to as teletherapy because the radiation source is located a predefined distance, approximately one meter, from the target. This treatment suffers from the disadvantage that tissue disposed between the radiation source and the target is exposed to radiation.
An alternative treatment system utilizing a point source of radiation is disclosed in U.S. Pat. Nos. 5,153,900 issued to Nomikos et al., 5,369,679 to Sliski et al., and 5,422,926 to Smith et al., all owned by the assignee of the present application, all of which are hereby incorporated by reference. The system includes a miniaturized, insertable probe capable of producing low power radiation in predefined dose geometries disposed about a predetermined location. This treatment is referred to as brachytherapy because the source is located close to or in some cases within the area receiving treatment. One advantage of brachytherapy is that the radiation is applied primarily to treat a predefined tissue volume, without significantly affecting the tissue in adjacent volumes.
Typical radiation therapy treatment involves positioning the insertable probe into or adjacent to the tumor or the site where the tumor or a portion of the tumor was removed to treat the tissue adjacent the site with a “local boost” of radiation. In order to facilitate controlled treatment of the site, it is desirable to support the tissue portions to be treated at a predefined distance from the radiation source. Alternatively, where the treatment involves the treatment of surface tissue or the surface of an organ, it is desirable to control the shape of the surface as well as the shape of the radiation field applied to the surface.
The treatment can involve the application of radiation, either continuously or intermittently, over an extended period of time. Therefore, it is desirable that the insertable probe be adjustably supported in a compliant manner to accurately position the radiation source with respect to the treated site and accommodate normal minor movements of the patient, such as movements associated with breathing.
In practice, the application of X-radiation to target tissue requires precise positioning of the X-ray source with respect to the target tissue, and maintaining that relative positioning throughout treatment. For therapeutic treatment of brain tumors using X-ray probes generally of the type disclosed in U.S. Pat. No. 5,153,900, stereotactic frames affixed to the patients skull are often used to effect the required relative positioning, as disclosed in U.S. Pat. No. 5,369,679. For treatment to other body parts, the user must otherwise support the relatively miniature X-ray probe. Such positioning using manual techniques has proven to be quite difficult.
Accordingly, it is an object of the present invention to provide an improved system for delivering radiation to a localized area. It is another object to provide an improved system for establishing and maintaining a desired position for therapeutic X-ray source.
SUMMARY OF THE INVENTION
The present invention is directed to a support system for a small, portable radiation source adapted for applying a dose of radiation to a volume of tissue such as a volume of tissue of the human body. In accordance with the present invention, the support system is adapted to support the small, portable radiation source in a substantially weightless state whereby the radiation source substantially maintains its horizontal and vertical position. The radiation source can be positioned by a physician for treatment and the radiation source will substantially maintain its horizontal and vertical position as well as its angular orientation about a first and second axis of rotation. In addition, the support system is adapted to permit minor movements of the area to be treated, such as to accommodate minor movements of a patient, for example, breathing.
The support system includes a support base, a rotatable, vertical shaft extending from the base along a first vertical axis. The support base may include a damping mechanism to damp the rotational motion of the vertical shaft relative to the support base, wherein the damping force is preferably proportional to the velocity of the vertical shaft. The support system further includes a horizontal extension coupled to the vertical shaft and a rotatable counterbalance coupled to the vertical shaft and extending in a diametrically opposite direction from the horizontal extension with respect to the first vertical axis. As the horizontal extension is rotated about the first vertical axis, the rotatable counterbalance remains diametrically opposite the horizontal extension to balance the support system. A portable radiation source can be coupled to a first end of a support cable which extends from the horizontal extension. Preferably, the horizontal extension is coupled to an upper portion of the vertical shaft and the rotatable counterbalance is coupled to a lower portion of the vertical shaft.
In one embodiment, the horizontal extension includes a first extension arm, coupled and extending from the vertical shaft and a second extension arm, rotatably coupled to the first extension arm by a rotatable coupling. The second extension arm is adapted to rotate about the second vertical axis with respect to the first extension arm.
In one embodiment, the vertical shaft includes a hollow portion and a vertical counterbalance weight, coupled to a second end of the support cable, which is suspended in the hollow portion. The weight of the vertical counterbalance weight can be adjusted to counterbalance the weight of the cable coupling and portable radiation source to permit the portable radiation source to be suspended in a substantially weightless configuration. Cable guides, such as pulleys, can be provided to guide the support cable along the first vertical axis into the first extension arm, along a second vertical axis through the rotatable coupling connecting the second extension arm to the first extension arm and through the second extension arm along the third vertical axis to the cable coupling and the portable radiation source. Thus, the vertical position of the portable radiation source can be easily adjusted and maintained while accommodat
Harte Kenneth J.
Sliski Alan P.
McDermott & Will & Emery
Photoelectron Corporation
Porta David P.
Yun Jurie
LandOfFree
Support system for a radiation treatment apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Support system for a radiation treatment apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Support system for a radiation treatment apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2608536