Surgery – Radioactive substance applied to body for therapy
Reexamination Certificate
1999-02-01
2001-01-30
Hindenburg, Max (Department: 3736)
Surgery
Radioactive substance applied to body for therapy
C600S439000
Reexamination Certificate
active
06179767
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to the treatment of organs, tumors, and other internal structures of living bodies with therapeutic radiation.
The present invention relates preferably to the field of radiation oncology, but it can also have other applications. The purpose of the invention is to be able to locate accurately the region or regions requiring radiation therapy within a patient even when the patient has undertaken any kind of motion or movement. As will be appreciated, it is very important to localize a therapeutic radiation treatment beam, i.e. align the beam accurately with the volume to be irradiated. Otherwise, adjacent healthy portions of the body may be injured by therapeutic radiation which is intended for the target organ, tumor, or other internal structure of a living body, In radiation therapy for the treatment of tumors or cancers, there is the problem of knowing the exact position (localization) of an internal organ or other internal structure to be irradiated because of natural movement of that internal structure within the body cavity. For example, the prostate or ovaries that are to undergo irradiation may move within the body cavity up to a centimeter between treatments.
Typically, preparation for radiation treatment includes obtaining tomographic images of the tumor a and surrounding tissue, usually recorded several days prior to the onset of radiation treatment. The 3-D reconstructieon of the images results in accurately locating the tumor in relation to the body as a whole. However, since radiation treatment may occur over a matter of months, there can be considerable shifts or displacements of the organ-containing tumor from the position originally determined from the tomograph. As a result, relying on the original tomographic positioning data can result in the radiation beam missing the target (tumor or other internal structure) either partially or even completely, and instead striking healthy tissue portions of the body that are not meant to be irradiated.
The present invention discloses the use of various types of implantable sensors and methods of locating internal body structures by communicating externally the instantaneous radiation at their locations.
BACKGROUND OF THE INVENTION
In general, the locations of internal tumors are obtained using CAT or MRI scans. However, these tumors within the body cavity may move due to motion of the patient (gravity pressure) or due to gastrointestinal pressures. It is essential to limit the treatment irradiation to the tumor site, and prevent irradiation of nearby healthy tissue. This is especially true for some organs, e.g. a liver, which may lie next to organs such as ovaries which are highly sensitive to radiation
A method of locating an internal injury is disclosed in U.S. Pat. No. 5,755,746 issued on May 26, 1998 to Arthur Lifshey et al. This approach involves positioning, at an external location that is approximately adjacent to the internal injury, a marker that is visualizable by X-rays, magnetic resonance, or ultrasonic waves. This approach appears to lack accuracy for tumors and other internal structures because the marker is external (and thus distant) from the internal injury, and because internal structures are likely to move within the body.
SUMMARY OF THE INVENTION
The present invention broadly provides a method of therapeutic treatment of an internal structure of a living body with therapeutic radiation which comprises the steps of:
a) implanting, at the aforesaid internal structure, a sensor to identify a selected location of the internal structure, the sensor being capable of emitting a signal in response to irradiation thereof by a beam of an investigative radiation,
b) scanning a region of the living body which includes the aforesaid internal structure with a beam of the aforesaid investigative radiation of a sufficiently low intensity to avoid causing injury to portions of the aforesaid region that are adjacent to the internal structure,
c) measuring the aforesaid signal to determine occurrence of a maximum intensity of that signal during scanning stop (b),
d) associating the aforesaid maximum intensity with a corresponding scanned location of the aforesaid region, and
e) focussing a selected intensity of the therapeutic radiation at a target determined from the aforesaid corresponding scanned location of the aforesaid region.
According to a preferred embodiment of the invention, the aforesaid investigative radiation may comprise the aforesaid therapeutic radiation itself.
The present invention also provides a system for therapeutic treatment of an internal structure of a living body with therapeutic radiation after implantation, at the aforesaid internal structure, of a sensor to identify a selected location of the internal structure, the sensor being capable of emitting a signal in response to irradiation thereof by a beam of investigative radiation. This inventive system comprises:
a) a beam projector for scanning a region of the living body which includes the aforesaid internal structure with a beam of the aforesaid investigative radiation of a sufficiently low intensity to avoid causing injury to portions of the region that are adjacent to the internal structure,
b) a signal measurement device for measuring said signal to determine occurrence of a maximum intensity of the aforesaid signal during scanning of the aforesaid region by the beam projector,
c) a computing apparatus for associating the aforesaid maximum intensity with a corresponding scanned location of the region, and
d) a controlled source of therapeutic radiation for focussing a selected intensity of the therapeutic radiation at a target determined from the aforesaid corresponding scanned location of the aforesaid region.
Where the aforesaid investigative radiation comprises the therapeutic radiation itself, then the afore controlled source of therapeutic radiation can serve as the aforesaid beam projector by projecting only a low intensity beam during investigative scanning of the aforesaid body region to identify the location of the implanted organ, tumor or other internal structure.
According to one preferred embodiment of the invention, the aforesaid sensor comprises a semiconductor diode capable of producing electric signals of an intensity that varies with the intensity of investigative radiation impinging upon said sensor during scanning of said region by said beam. For this purpose, the sensor includes wires implanted in the living body and extending to the surface of the body (e.g. to a connector at the navel) for connecting the semiconductor diode to an ammeter or other electric signal measurement device.
According to another embodiment, the sensor comprises a scintillator material capable of producing light signals of an intensity that varies with the intensity of investigative radiation impinging upon said sensor during scanning of said region by said beam. This type of sensor comprises light- transmitting fibers connecting the scintillator material to a suitable light signal measurement device.
According to an alternative embodiment of the invention, the sensor comprises a piezoelectric material capable of producing acoustic signals of an intensity that varies with the intensity of investigative radiation impinging upon the sensor during scanning of the body region by the investigative beam. In this case, the signal measurement device comprises an acoustic microphone which is disposed external to said living body to detect a maximum of the acoustic signals during beam scanning.
Alternatively, the sensor comprises a piezoelectric material capable of producing electrical signals of an intensity that varies with the intensity of investigative radiation impinging upon said sensor during scanning of said region by said beam. In this case, the sensor comprises wires implanted in the living body for connecting the piezoelectric material to an electric signal measurement device (e.g. via a surface connector at the navel).
As a further alternative embodiment, the sensor comprises an x-ray em
von Gutfeld Robert Jacob
Ziegler James Francis
August Casey P.
Hindenburg Max
International Business Machines - Corporation
LandOfFree
Focussing of therapeutic radiation on internal structures of... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Focussing of therapeutic radiation on internal structures of..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Focussing of therapeutic radiation on internal structures of... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2532696