Patient alignment system with external measurement and object coordination for radiation therapy system

Abstract

A patient alignment system for a radiation therapy system. The alignment system includes multiple external measurement devices which obtain position measurements of components of the radiation therapy system which are movable and/or are subject to flex or other positional variations. The alignment system employs the external measurements to provide corrective positioning feedback to more precisely register the patient and align them with a radiation beam. The alignment system can be provided as an integral part of a radiation therapy system or can be added as an upgrade to existing radiation therapy systems.

1 .- 20 . (canceled) 
     
     
         21 . A radiation therapy delivery system comprising  1   a  patient fixation device configured to secure a patient with respect to the patient fixation device;
 a patient positioner interconnected to the patient fixation device so as to position the patient fixation device in three translational axes and three rotational axes;   a primary position measurement system configured to receive images of at least one component of the radiation therapy delivery system and to develop a treatment image indicative of the orientation of the at least one component with respect to the patient prior to treatment;   a secondary position measurement system configured to provide movement signals indicative of the movement of the at least one component; and   a control system that controls delivery of particles to the patient during treatment, the control system further configured to evaluate the treatment image and the movement signals and to determine an actual orientation of the at least one component prior to treatment, the control system further configured to compare the actual orientation of the at least one component prior to treatment to a desired orientation of the at least one component and, if the actual orientation does not meet a pre-determined criteria for correspondence with the desired orientation, the control system moves the at least one component such that the actual orientation more closely corresponds to the desired orientation during delivery of the particles.   
     
     
         22 . The system of  claim 21 , wherein the at least one component comprises the patient positioner, a gantry of the radiation therapy delivery system, a nozzle of the radiation therapy delivery system, a radiation source of the radiation therapy delivery system, an aperture of the radiation therapy delivery system, or an imager of the radiation therapy system. 
     
     
         23 . The system of  claim 21 , wherein the primary position measurement system receives information from a plurality of optical cameras configured to independently obtain optical images of the at least one component. 
     
     
         24 . The system of  claim 23 , wherein the system determines a three dimensional location of a monument associated with the at least one component using the optical images of the at least one component. 
     
     
         25 . The system of  claim 23 , wherein the primary position measurement system receives information from a plurality of laser measurement devices or a plurality of radio location devices. 
     
     
         26 . The system of  claim 21 , wherein the secondary position measurement system is configured to receive information from a plurality of rotary encoders, a plurality of linear encoders, or a plurality of servos. 
     
     
         27 . The system of  claim 21 , wherein the primary position measurement system images a plurality of components, including a nozzle of the radiation therapy delivery system, and the control system adjusts the patient positioner such that the patient positioner is within a pre-determined criteria of a desired orientation of the patient positioner. 
     
     
         28 . The system of  claim 21 , wherein the primary position measurement system defines a set point of reference within a field of view of the plurality of cameras and determines the actual orientation and the desired orientation of the at least one component with respect to the set point of reference. 
     
     
         29 . A radiation therapy delivery system comprising:
 means for securing a patient in a substantially immobile orientation;   means for positioning the securing means in three translational axes and three rotational axes;   means for developing a treatment image indicative of an orientation of at least one component of the radiation therapy delivery system with respect to the patient prior to treatment, the at least one component selected from a group consisting of the positioning means, a gantry of the radiation therapy delivery system, a nozzle of the radiation therapy delivery system, a radiation source of the radiation therapy delivery system, an aperture of the radiation therapy delivery system, and an imager of the radiation therapy system;   means for developing movement signals indicative of the movement of the at least one component; and   a control system that controls delivery of particles to the patient during treatment, the control system further configured to evaluate the treatment image and the movement signals and to determine an actual orientation of the at least one component prior to treatment, the control system further configured to compare the actual orientation of the at least one component prior to treatment to a desired orientation of the at least one component and, if the actual orientation does not meet a pre-determined criteria for correspondence with the desired orientation, the control system moves the at least one component such that the actual orientation more closely corresponds to the desired orientation during delivery of the particles.   
     
     
         30 . The system of  claim 29 , wherein the means for developing a treatment image comprises a plurality of optical cameras configured to independently obtain optical images of the at least one component. 
     
     
         31 . The system of  claim 30 , wherein the means for developing a treatment image determines a three dimensional location of a monument associated with the at least one component using the optical images of the at least one component. 
     
     
         32 . The system of  claim 29 , wherein the means for developing a treatment image defines a set point of reference within a field of view of the plurality of cameras and determines the actual orientation and the desired orientation of the at least one component with respect to the set point of reference. 
     
     
         33 . The system of  claim 29 , wherein the means for developing movement signals comprises a plurality of local position feedback devices. 
     
     
         34 . A method of controlling movement of at least one component in a radiation therapy delivery system, the system comprising a patient fixation device configured to secure a patient with respect to the patient fixation device and a patient positioner interconnected to the patient fixation device, the method comprising:
 developing a treatment image indicative of the orientation of the at least one component with respect to the patient prior to treatment;   developing movement signals indicative of the movement of the at least one component; and   evaluating the treatment image and the movement signals to determine an actual orientation of the at least one component prior to treatment;   comparing the actual orientation of the at least one component prior to treatment to a desired orientation of the at least one component; and   moving the at least one component such that the actual orientation more closely corresponds to the desired orientation during delivery of the particles.   
     
     
         35 . The method of  claim 34 , wherein moving the at least one component comprises moving the at least one component within a pre-determined criteria of the desired orientation. 
     
     
         36 . The method of  claim 34 , wherein developing a treatment image comprises capturing a plurality of optical images of the at least one component. 
     
     
         37 . The method of  claim 36 , wherein developing a treatment image comprises determining a three dimensional location of a monument associated with the at least one component using the plurality of optical images of the at least one component. 
     
     
         38 . The method of  claim 34 , wherein the at least one component is selected from a group consisting of the patient positioner, a gantry of the radiation therapy delivery system, a nozzle of the radiation therapy delivery system, a radiation source of the radiation therapy delivery system, an aperture of the radiation therapy delivery system, and an imager of the radiation therapy system.