METHOD AND APPARATUS FOR DIRECTING A RADIATION BEAM TOWARD A TUMOR OR THE LIKE

• US 3,794,840 A
• Filed: 03/27/1972
• Issued: 02/26/1974
• Est. Priority Date: 03/27/1972
• Status: Expired due to Term

• Current Assignee: Walter P. Scott
• Original Assignee: Walter P. Scott
• Inventors: Scott, Walter P.
• Primary Examiner(s): Dixon, Harold A.
• Application Number:
  US05/238,322
• Time in Patent Office: 701 Days
• Field of Search: 250/71.5S,61.5,64,83.3R
• US Class Current: 378/65
• CPC Class Codes: A61B 2090/392 Radioactive markers
• CPC Class Codes: A61N 2005/1051 using an active marker markers in general A61B90/39
• CPC Class Codes: A61N 5/1049 for verifying the position of the patient with respect to the radiation beam
• CPC Class Codes: G21K 5/10 with provision for relative movement of beam source and object to be irradiated

Abstract

Method and apparatus for accurately directing a therapeutic radiation beam to a tumor or the like within a human body, including the implantation at the tumor of a source emitting radioactive rays traveling in a straight line therefrom, sensing this ray emission to determine a straight line path to the tumor, and directing the radiation beam toward the tumor by having the center line of the radiation beam coincide with the straight line path determined from the ray emitting source. Preferably, a radioactive isotope is implanted in the tumor as the source, and a collimating tubular channel member is selectively mounted on the radiation head of a radiation teletheraphy machine with the axis of the channel member coinciding with the center of the beam from the radiation head. One end of the channel member is open to receive rays emitted from the implanted source and the other end is associated with a device for detecting these rays. The detecting device produces an electrical signal in response to the rays sensed, this electrical signal being greater as the straight line path of emitted rays come into coincidence with the axis of the opening in the channel member, and the magnitude of the electrical signal is visually displayed. The teletherapy machine operator manipulates either the patient or the radiation head until the displayed signal indicates a maximum magnitude, removes the channel member and energizes the radiation head.

Claims

1. A method of accurately directing a therapeutic radiation beam to a point within a body at which radiation therapy is required, said therapeutic radiation beam having sufficient voltage and intensity to therapeutically treat tumors or the like within said body, said method comprising the steps of locating within said body at said point a source which emanates straight line rays therefrom, sensing said ray emission to determine a straight line path to said source, and aligning the center of said therapeutic radiation beam to coincide with said straight line path whereby said therapeutic radiation beam will be directed to said point.

2. A method of accurately directing a radiation beam as defined in claim 1 and further characterized in that said source is a radioactive isotope.

3. A methoD of accurately directing a radiation beam as defined in claim 2 and further characterized in that said sensing of said ray emission includes providing a straight line channel for receiving a portion of said ray emission and includes detecting the magnitude of said channeled ray emission, and in that said center of said radiation beam is directed to coincide with the straight line path of said channeled ray emission when the magnitude of said channeled ray emission is determined to have a maximum value.

4. In combination with a radiation teletherapy machine having a head portion from which a radiation beam is directed, the improvement comprising means for sensing the presence of a source of radioactive ray emission and determining a straight line path to said source, and means for aligning the center line of said radiation beam to coincide with the said straight line path to said source determined by said sensing means whereby said radiation beam will be directed to said source of radiation emission.

5. In combination with a radiation teletherapy machine having a head portion from which a therapeutic radiation beam is directed, said therapeutic radiation beam having sufficient voltage and intensity to therapeutically treat tumors or the like within a body, the improvement comprising a tubular channel member which is open at one end thereof and associated at its other end with means for detecting radiation rays received through the open end of said tubular member, said detecting means producing a signal which varies in proportion to the magnitude of the radiation rays received through said channel member, means mounting said channel member and associated detecting means on said teletherapy machine head for movement to a position at which the axis of said channel member coincides with the center line of the therapeutic radiation beam emitted by said head, and indicating means connected to said detecting means for indicating the magnitude of said radiation rays received through said channel member.

6. In combination with a radiation teletherapy machine, the improvement defined in claim 5 and further characterized in that said detecting means produces an electrical signal in response to receiving said radiation rays through said channel member, and in that said indicating means includes means for visually indicating a selected parameter of said electrical signal produced by said detecting means.

7. In combination with a radiation teletherapy machine, the improvement defined in claim 5 and further characterized in that said mounting means includes pivotal connection means permitting said channel member and associated detecting means to move in a plane perpendicular to said center line of said radiation beam whereby said channel member and associated detecting means can be selectively moved into and out of the path of said radiation beam, and in that said mounting means includes a sliding connector means permitting said channel member and associated detecting means to be moved selectively in a direction along said center line of said radiation beam.

8. In combination with a radiation teletherapy machine having a head portion from which a radiation beam is directed, the improvement comprising a tubular collimator device which is open at one end thereof and mounted at its other end to a detector device for detecting gamma rays received through the open end of said collimator, and for generating electrical pulses at a repetition rate which increases as the magnitude of the gamma waves detected thereby increases, said collimator device and said associated detector device being mounted on said teletherapy machine for selective movement in a plane lying perpendicular to the center line of said radiation beam and in a direction along said center line whereby said collimator device and said associated detector device can be moved to a position at which the axis of said collimator coincides with the centerline of said radiation beam and can then be moved along said center liNe toward and away from said head portion, read-out analyzer means connected to said detector device to receive said electrical pulses therefrom, said analyzer means including a visual display indicating the frequency of the electrical pulses received from said detector device and thereby indicating the magnitude of the gamma rays detected by said detector device.