Radiation treatment planning that considers the dimensions of volumes in a treatment target
For planning radiation treatment using spot scanning, also known as pencil beam scanning, the size and/or shape of the treatment target is considered when determining the placement and density of spots in the treatment target. For example, when generating a radiation treatment plan, the size and/or shape of the treatment target can be considered when determining the placement and density of spots in the treatment target. During treatment planning, the treatment target can be separated into regions corresponding to different target volumes in the treatment target, and the placement and density of spots (the amount of spacing between spots) in each region can be determined independently for each region according to the size and/or shape of the region.
1 . A computer system, comprising:
a memory storing instructions; and
a processor configured to execute the instructions to cause the computer system to perform a method for planning radiation treatment, the radiation treatment including spot scanning of a treatment target, and the method including
accessing a representation of the treatment target in which the treatment target is separated into at least a first region and a second region, first physical dimensions of the first region being different from second physical dimensions of the second region,
determining a first pattern of first spots inside the first region, an amount of spacing between the first spots in the first pattern being based on the first physical dimensions,
determining a second pattern of second spots inside the second region, an amount of spacing between the second spots in the second pattern being based on the second physical dimensions; and
storing, in the memory, the first pattern and the second pattern for access by a radiotherapy machine configured to perform the spot scanning of the treatment target based on a radiation treatment plan, the radiation treatment plan being based on the first pattern and the second pattern.
2 . The computer system of claim 1 , wherein
the first region is smaller than the second region; and
the amount of spacing between the first spots in the first pattern is less than the amount of spacing between the second spots in the second pattern.
3 . The computer system of claim 1 , wherein
the first region is narrower than the second region in at least one dimension; and
the amount of spacing between the first spots in the first pattern is less than the amount of spacing between the second spots in the second pattern.
4 . The computer system of claim 1 , wherein
the first pattern and the second pattern correspond to initial conditions; and
the method further comprises
assigning values of weights to each of the first spots and each of the second spots,
determining whether an objective defined for the radiation treatment is satisfied using the values of the weights, and
adjusting one or more of the values of the weights in response to determining the objective is not satisfied.
5 . The computer system of claim 1 , wherein
the first pattern and the second pattern correspond to initial conditions; and
the method further comprises
assigning values of weights to each of the first spots and each of the second spots,
determining whether an objective defined for the radiation treatment is satisfied using the values of the weights, and
adjusting at least one of the first pattern or the second pattern in response to determining the objective is not satisfied.
6 . The computer system of claim 1 , wherein the first region and the second region are physically separated from each other.
7 . The computer system of claim 1 , wherein
the representation of the treatment target separates the treatment target into the first region, the second region and a third region, the third region being adjacent to both the first region and the second region; and
an amount of spacing between third spots in a third pattern inside the third region is the same as one of
the amount of spacing between the first spots in the first pattern, or
the amount of spacing between the second spots in the second pattern.
8 . The computer system of claim 1 , wherein
the determining the first pattern is based on a size or a shape of the first region; and
the determining the second pattern is based on a size or a shape of the second region.
9 . A non-transitory computer-readable storage medium storing computer-executable instructions that, when executed by a processor of a computer system, cause the computer system to perform a method for planning radiation treatment, the radiation treatment including spot scanning of a treatment target, and the method including
accessing a representation of the treatment target in which the treatment target is separated into at least a first region and a second region, a first area of the first region being different from a second area of the second region,
determining a first pattern of first spots inside the first region, a density of the first spots in the first pattern being based on the first area,
determining a second pattern of second spots inside the second region, a density of the second spots in the second pattern being based on the second area, and
storing, in a memory, the first pattern and the second pattern for access by a radiotherapy machine configured to perform the spot scanning of the treatment target based on a radiation treatment plan, the radiation treatment plan being based on the first pattern and the second pattern.
10 . The non-transitory computer-readable storage medium of claim 9 , wherein
the first region is smaller than the second region; and
the density of the first spots in the first pattern is greater than the density of the second spots in the second pattern.
11 . The non-transitory computer-readable storage medium of claim 9 , wherein
a first dimension of the first region is less than a second dimension of the second region, the first dimension corresponding to the second dimension; and
the density of the first spots in the first pattern is greater than the density of the second spots in the second pattern.
12 . The non-transitory computer-readable storage medium of claim 9 , wherein
the first pattern and the second pattern correspond to initial conditions; and
the method further comprises
assigning values of weights to each of the first spots and each of the second spots,
determining whether an objective defined for the radiation treatment is satisfied using the values of the weights, and
adjusting one or more of the values of the weights in response to determining the objective is not satisfied.
13 . The non-transitory computer-readable storage medium of claim 9 , wherein
the first pattern and the second pattern correspond to initial conditions; and
the method further comprises
assigning values of weights to each of the first spots and each of the second spots,
determining whether an objective defined for the radiation treatment is satisfied using the values of the weights, and
adjusting at least one of the first pattern or the second pattern in response to determining the objective is not satisfied.
14 . The non-transitory computer-readable storage medium of claim 9 , wherein
the representation of the treatment target separates the treatment target into the first region, the second region and a third region, the third region being adjacent to both the first region and the second region; and
a density of third spots in a third pattern inside the third region is the same as one of
the density of the first spots in the first pattern, or
the density of the second spots in the second pattern.
15 . A computer-implemented method for planning radiation treatment, the radiation treatment including spot scanning of a treatment target, and the computer-implemented method comprising:
accessing a description of the treatment target according to which the treatment target is virtually separated into at least a first region and a second region, first physical dimensions of the first region being different from second physical dimensions of the second region;
determining a first density of first spots inside the first region based on the first physical dimensions;
determining a second density of second spots inside the second region based on the second physical dimensions, the second density being different from the first density;
determining a first pattern for the first spots in the first region, the first spots in the first pattern having at least the first density;
determining a second pattern for the second spots in the second region, the second spots in the second pattern having at least the second density; and
storing, in a memory, the first pattern and the second pattern for access by a radiotherapy machine configured to perform the spot scanning of the treatment target based on a radiation treatment plan, the radiation treatment plan being based on the first pattern and the second pattern.
16 . The computer-implemented method of claim 15 , wherein
the first region is smaller than the second region; and
the first density is greater than the second density.
17 . The computer-implemented method of claim 15 , wherein
the first region is narrower than the second region in at least one dimension; and
the first density is greater than the second density.
18 . The computer-implemented method of claim 15 , wherein
the first pattern and the second pattern correspond to initial conditions; and
the computer-implemented method further comprises
assigning values of weights to each of the first spots and each of the second spots,
determining whether an objective defined for the radiation treatment is satisfied using the values of the weights, and
adjusting one or more of the values of the weights in response to determining the objective is not satisfied.
19 . The computer-implemented method of claim 15 , wherein
the first pattern and the second pattern correspond to initial conditions; and
the computer-implemented method further comprises
assigning values of weights to each of the first spots and to each of the second spots,
determining whether an objective defined for the radiation treatment is satisfied using the values of the weights, and
adjusting at least one of the first density or the second density in response to determining the objective is not satisfied.
20 . The computer-implemented method of claim 15 , wherein
the first region and the second region are physically separated from each other; and
the determining the first density and the determining the second density are performed concurrently with and independently of each other.
21 . The computer-implemented method of claim 15 , wherein
the treatment target is virtually separated into the first region, the second region and a third region that is adjacent to both the first region and the second region; and
a density of third spots in a third pattern inside the third region is the same as one of the first density or the second density.