Radiation therapy system using plural treatment plans

Abstract

The invention relates to a system for delivering a radiation treatment to a structure (21) within a body. In the system, a plurality of treatments plans is provided, each treatment plan being associated to one of a plurality of predefined possible position (33a; 33b) of the structure (21), which area regularly distributed on at least one predefined surface (32a; 32b). A control unit is configured to determine the position of the structure during the treatment and to select a treatment plan which is associated with a predefined possible position having a smallest distance to the determined position, for controlling the radiation source in response to the detection of the position. Moreover, the invention relates to a computer program for controlling the system and to a planning unit for generating the treatment plans.

1 . A planning device for generating treatment plans for controlling a radiation treatment to a structure within a body in a radiation therapy system, the planning device comprising:
 a memory; and   a processor in communication with the memory, the processor being configured to:
 generate a first treatment plan based on a reference image of the structure, and 
 generate further treatment plans on the basis of deformed versions of the reference image, wherein a reference point of the structure is located at a reference position in the reference image and wherein the reference point of the structure is located at one of a plurality of predefined possible shifted positions in each of the deformed versions of the reference image, the predefined possible shifted positions corresponding to possible positions of the reference point of the structure during the treatment and being regularly distributed on at least one predefined surface. 
   
     
     
         2 . The planning device as defined in  claim 1 , wherein the reference point of the structure corresponds to an estimated center of mass of the structure. 
     
     
         3 . The planning device as defined in  claim 1 , wherein, at each predefined possible shifted position of the structure, the reference point of the structure is located on the at least one predefined surface. 
     
     
         4 . The planning device defined in  claim 3 , wherein the at least one predefined surface surrounds the reference point of the structure at the reference position. 
     
     
         5 . The planning device as defined in  claim 4 , wherein the predefined surfaces correspond to concentric spheres or ellipsoids centered at the reference point of the structure at the reference position. 
     
     
         6 . The planning device as defined in  claim 5 , wherein directions of major axes of the ellipsoids correspond to a direction in which the structure moves with a probability that is higher than a probability for movements of the structure in other directions. 
     
     
         7 . The planning device as defined in  claim 1 , further comprising a control unit configured to determine the position of the reference point of the structure during the treatment and to select a treatment plan, which is associated with a predefined possible position of the reference point having a smallest distance to the determined position, for controlling the radiation source in response to the detection of the position. 
     
     
         8 . A method for execution by a processor for generating treatment plans for controlling a radiation treatment to a structure within a body in a radiation therapy system, the method comprising:
 generating a first treatment plan based on a reference image of the structure; and   generating further treatment plans on the basis of deformed versions of the reference image, wherein a reference point of the structure is located at a reference position in the reference image and wherein the reference point of the structure is located at one of a plurality of predefined possible shifted positions in each of the deformed versions of the reference image, the predefined possible shifted positions corresponding to possible positions of the reference point of the structure during the treatment and being regularly distributed on at least one predefined surface.   
     
     
         9 . The method as defined in  claim 8 , wherein the reference point of the structure corresponds to an estimated center of mass of the structure. 
     
     
         10 . The method as defined in  claim 8 , wherein, at each predefined possible shifted position of the structure, the reference point of the structure is located on the at least one predefined surface. 
     
     
         11 . The method defined in  claim 10 , wherein the at least one predefined surface surrounds the reference point of the structure at the reference position. 
     
     
         12 . The method as defined in  claim 11 , wherein the predefined surfaces correspond to concentric spheres or ellipsoids centered at the reference point of the structure at the reference position. 
     
     
         13 . The method as defined in  claim 12 , wherein directions of major axes of the ellipsoids correspond to a direction in which the structure moves with a probability that is higher than a probability for movements of the structure in other directions. 
     
     
         14 . A non-transitory machine-readable storage medium encoded with instructions for execution by a processor for generating treatment plans for controlling a radiation treatment to a structure within a body in a radiation therapy system, the non-transitory machine-readable storage medium comprising:
 instructions for generating a first treatment plan based on a reference image of the structure; and   instructions for generating further treatment plans on the basis of deformed versions of the reference image, wherein a reference point of the structure is located at a reference position in the reference image and wherein the reference point of the structure is located at one of a plurality of predefined possible shifted positions in each of the deformed versions of the reference image, the predefined possible shifted positions corresponding to possible positions of the reference point of the structure during the treatment and being regularly distributed on at least one predefined surface.   
     
     
         15 . The non-transitory machine-readable storage medium as defined in  claim 14 , wherein the reference point of the structure corresponds to an estimated center of mass of the structure. 
     
     
         16 . The non-transitory machine-readable storage medium as defined in  claim 14 , wherein, at each predefined possible shifted position of the structure, the reference point of the structure is located on the at least one predefined surface. 
     
     
         17 . The non-transitory machine-readable storage medium defined in  claim 16 , wherein the at least one predefined surface surrounds the reference point of the structure at the reference position. 
     
     
         18 . The non-transitory machine-readable storage medium as defined in  claim 17 , wherein the predefined surfaces correspond to concentric spheres or ellipsoids centered at the reference point of the structure at the reference position. 
     
     
         19 . The non-transitory machine-readable storage medium as defined in  claim 18 , wherein directions of major axes of the ellipsoids correspond to a direction in which the structure moves with a probability that is higher than a probability for movements of the structure in other directions.