Treatment planning method and radiotherapy system

1. A method of making a treatment plan with a treatment planning system, the treatment plan being applicable to a radiotherapy system, the method comprising:

acquiring a preset dose distribution scheme;

generating at least one radiation dose distribution scheme to be used with the treatment planning system, wherein the treatment plan system is generated based on at least one of beam energy of the radiotherapy system, a size of a collimator of the radiotherapy system, a radiation angle and radiation time of the radiotherapy system; and

comparing the at least one radiation dose distribution scheme to be used with the preset dose distribution scheme, and determining, among the at least one radiation dose distribution scheme, a radiation dose distribution scheme that is the closest to the preset dose distribution scheme to make the treatment plan,

wherein the treatment planning system includes a preset algorithm, the preset algorithm generates the at least one radiation dose distribution scheme to be used based on a function of f(Φ, θ, B, D, t, d), wherein the variable Φ is an indication of rotational angles of a therapeutic head of the radiotherapy system which is rotatable in a first dimension relative to the target region, the variable θ is an indication of swing angles of the therapeutic head relative to the target region in a second dimension, the second dimension is different from the first dimension, and B is an indication of beam energy of the radiotherapy system, the variable D is an indication of a distance from an emission point of a radioactive source of the therapeutic head to the target region, the variable t is an indication of radiation time, and the variable d is an indication of radiation field parameters of the therapeutic head of the radiotherapy system.

2. The method according to claim 1 , wherein the therapeutic head comprises a conformal therapeutic head with a single radioactive source, and the function of f(Φ, θ, B, D, t, d) included in the preset algorithm comprises:

S

=

∑

i

=

1

n

⁢

{

f

⁡

(

Φ

i

,

θ

i

,

B

,

D

i

,

t

i

,

d

i

)

}

wherein S is an indication of an accumulative dose distribution on the target region and n is an indication of a number of times of position changes of the radioactive source.

3. The method according to claim 2 , wherein the therapeutic head comprises more than two conformal therapeutic heads, and the conformal therapeutic heads are all disposed and movable on a same rotatable gantry, and the function of f(Φ, θ, B, D, t, d) included in the preset algorithm comprises:

§

1

=

∑

i

=

1

p

⁢

{

∑

i

=

1

n

⁢

{

f

⁡

(

Φ

i

,

θ

i

,

B

,

D

i

,

t

i

,

d

i

)

}

}

wherein, § 1 is an accumulative dose distribution on the target region, p is an indication of a number of the conformal therapeutic heads.

4. The method according to claim 1 , wherein the therapeutic head includes a single focused therapeutic head comprising a plurality of radioactive sources, the focused therapeutic head is configured to continue to move with a rotatable gantry, and the function of f(Φ, θ, B, D, t, d) included in the preset algorithm comprises:

§

2

=

∑

i

=

1

o

⁢

{

∑

i

=

1

m

⁢

{

f

⁡

(

Φ

i

,

θ

i

,

B

,

D

i

,

t

i

,

d

i

)

}

}

wherein § 2 is an accumulative dose distribution on the target region, o is a number of times of position changes of the focused therapeutic head, and m is an indication of a number of the radioactive sources.

5. The method according to claim 1 , wherein the therapeutic head comprises at least two focused therapeutic heads, the at least two focused therapeutic heads are disposed on a same rotatable gantry, and the function of f(Φ, θ, B, D, t, d) included in the preset algorithm comprises:

§3

=

∑

i

=

1

q

⁢

{

∑

i

=

1

o

⁢

{

∑

i

=

1

m

⁢

{

f

⁡

(

Φ

i

,

θ

i

,

B

,

D

i

,

t

i

,

d

i

)

}

}

}

wherein § 3 is an accumulative dose distribution on the target region, q is an indication of a number of the focused therapeutic heads.

6. The method according to claim 1 , wherein the therapeutic head comprises at least one focused therapeutic head and at least one conformal therapeutic head which are all disposed on a same rotatable gantry for continuous movement, and the function of f(Φ, θ, B, D, t, d) included in the preset algorithm comprises:

§

=

§

1

+

§

3

=

∑

i

=

1

p

⁢

{

S

1

⁢

⁢

i

}

+

∑

i

=

1

q

⁢

{

S

2

⁢

i

}

=

∑

i

=

1

p

⁢

{

∑

i

=

1

n

⁢

{

f

⁡

(

Φ

i

,

θ

i

,

B

,

D

i

,

t

i

,

d

i

)

}

}

+

∑

i

=

1

q

⁢

{

∑

i

=

1

o

⁢

{

∑

i

=

1

m

⁢

{

f

⁡

(

Φ

i

,

θ

i

,

B

,

D

i

,

t

i

,

d

i

)

}

}

}

,

wherein § 1 is an accumulative dose distribution of the conformal therapeutic head, § 3 is an accumulative dose distribution of the focused therapeutic head, p is an indication of a number of the conformal therapeutic head, and n is an indication of a number of times of positional change of the radioactive source in the conformal therapeutic head, q is an indication of a number of the focused therapeutic head, o is an indication of a number of times of positional change of the focused therapeutic head, and m is an indication of a number of a radioactive sources in the focused therapeutic head.

7. The method according to claim 1 , wherein the radiation field parameters of the therapeutic head are determined by a collimator of the therapeutic head, and

when the collimator is an aperture collimator, the collimator includes a plurality of collimation holes, and the radiation field parameters are the sizes of the collimation holes; or,

when the collimator is a multi-leaf collimator, the radiation field parameters are related to a shaped region through which radiation beams that is generated by the therapeutic head passes, wherein the shaped region is shaped by leaves of the collimator.

8. The method according to claim 1 , wherein the therapeutic head is rotatable along a central axis of a rotatable gantry, and the first dimension is defined to be a direction of rotation movement of the therapeutic head.

9. The method according to claim 1 , wherein the therapeutic head is moveable along a central axis of a rotatable gantry, and a second dimension is defined to be along a direction of the central axis.

10. The method according to claim 9 , wherein the plurality of radiation dose distribution schemes are generated based on different radiation angles of the therapeutic head with respect to the target region in the second dimension.

11. The method according to claim 1 , wherein at least one variable in the function of f(Φ, θ, B, D, t, d) is zero.

12. The method according to claim 1 , wherein the preset dose distribution scheme is calculated with semi-empirical model or Boltzmann transport equation.

13. The method according to claim 1 , wherein the radiation angle is variable.

14. The method according to claim 1 , wherein the comparing the at least one radiation dose distribution scheme to be used with the preset dose distribution scheme, and determining, among the at least one radiation dose distribution scheme, a radiation dose distribution scheme that is the closest to the preset dose distribution scheme to make the treatment plan comprises:

comparing the at least one radiation dose distribution scheme to be used with the preset dose distribution scheme;

when a difference between the at least one radiation dose distribution scheme to be used and the preset dose distribution scheme is greater than a safety threshold, adjusting a parameter of the treatment planning system to regenerate the at least one radiation dose distribution scheme to be used;

comparing the at least one regenerated radiation dose distribution scheme to be used with the preset dose distribution scheme, and determining, among the at least one regenerated radiation dose distribution scheme, a radiation dose distribution scheme that is the closest to the preset dose distribution scheme to make the treatment plan.

15. The method according to claim 1 , wherein the comparing the at least one radiation dose distribution scheme to be used with the preset dose distribution scheme, and determining, among the at least one radiation dose distribution scheme, a radiation dose distribution scheme that is the closest to the preset dose distribution scheme to make the treatment plan comprises:

comparing a difference between the at least one radiation dose distribution scheme to be used and the preset dose distribution scheme with a safety threshold, and determining a radiation dose distribution scheme to be used based on a result of the comparison to make the treatment plan.

16. A radiotherapy system, comprising:

at least one therapeutic head configured to generate a radiation beam;

a treatment couch configured to define a position of a target region;

a gantry configured to support the at least one therapeutic head, and move the therapeutic head relative to the treatment couch in multiple dimensions; and

a treatment planning apparatus, the treatment planning apparatus including a processor, wherein the processor is configured with instructions to:

acquire a preset dose distribution scheme;

generate at least one radiation dose distribution scheme to be used, wherein the treatment plan is generated based on at least one of beam energy of the radiotherapy system, a size of a collimator of the radiotherapy system, a radiation angle and radiation time of the radiotherapy system; and

compare the at least one radiation dose distribution scheme to be used with the preset dose distribution scheme, and determine, among the at least one radiation dose distribution scheme, a radiation dose distribution scheme that is the closest to the preset dose distribution scheme to make the treatment plan,

wherein the treatment planning apparatus includes a preset algorithm, the preset algorithm generates the at least one radiation dose distribution scheme to be used based on a function of f(Φ, θ, B, D, t, d), wherein the variable Φ is an indication of rotational angles of a therapeutic head of the radiotherapy system which is rotatable in a first dimension relative to the target region, the variable θ is an indication of swing angles of the therapeutic head relative to the target region in a second dimension, the second dimension is different from the first dimension, and B is an indication of beam energy of the radiotherapy system, the variable D is an indication of a distance from an emission point of a radioactive source of the therapeutic head to the target region, the variable t is an indication of radiation time, and the variable d is an indication of radiation field parameters of the therapeutic head of the radiotherapy system.

17. A method of making a treatment plan, the treatment plan being applicable to a radiotherapy system, the method comprising:

acquiring a preset dose distribution scheme;

generating a radiation dose distribution scheme to be used with a treatment planning system, wherein the treatment plan system is generated based on at least one of beam energy of the radiotherapy system, a size of a collimator of the radiotherapy system, a radiation angle and radiation time of the radiotherapy system such that a continuous change of radiation dose in a radiation region of the beam is formed with a specific spatial distribution; and

comparing the radiation dose distribution scheme to be used with the preset dose distribution scheme, and determining a radiation dose distribution scheme that is the closest to the preset dose distribution scheme to make the treatment plan,

wherein the treatment planning system includes a preset algorithm, the preset algorithm generates the at least one radiation dose distribution scheme to be used based on a function of f(Φ, θ, B, D, t, d), wherein the variable Φ is an indication of rotational angles of a therapeutic head of the radiotherapy system which is rotatable in a first dimension relative to the target region, the variable θ is an indication of swing angles of the therapeutic head relative to the target region in a second dimension, the second dimension is different from the first dimension, and B is an indication of beam energy of the radiotherapy system, the variable D is an indication of a distance from an emission point of a radioactive source of the therapeutic head to the target region, the variable t is an indication of radiation time, and the variable d is an indication of radiation field parameters of the therapeutic head of the radiotherapy system.

18. The method according to claim 17 , wherein the therapeutic head comprises a conformal therapeutic head with a single radioactive source, and the function of f(Φ, θ, B, D, t, d) included in the preset algorithm comprises:

S

=

∑

i

=

1

n

⁢

{

f

⁡

(

Φ

i

,

θ

i

,

B

,

D

i

,

t

i

,

d

i

)

}

wherein S is an indication of an accumulative dose distribution on the target region and n is an indication of a number of times of position changes of the radioactive source.

19. The method according to claim 17 , wherein the therapeutic head includes a single focused therapeutic head comprising a plurality of radioactive sources, the focused therapeutic head is configured to continue to move with a rotatable gantry, and the function of f(Φ, θ, B, D, t, d) included in the preset algorithm comprises:

§

2

=

∑

i

=

1

o

⁢

{

∑

i

=

1

m

⁢

{

f

⁡

(

Φ

i

,

θ

i

,

B

,

D

i

,

t

i

,

d

i

)

}

}

wherein § 2 is an accumulative dose distribution on the target region, o is a number of times of position changes of the focused therapeutic head, and m is an indication of a number of the radioactive sources.

20. The method according to claim 17 , wherein the therapeutic head comprises at least one focused therapeutic head and at least one conformal therapeutic head which are all disposed on a same rotatable gantry for continuous movement, and the function of f(Φ, θ, B, D, t, d) included in the preset algorithm comprises:

§

=

§

1

+

§

3

=

∑

i

=

1

p

⁢

{

S

1

⁢

⁢

i

}

+

∑

i

=

1

q

⁢

{

S

2

⁢

i

}

=

∑

i

=

1

p

⁢

{

∑

i

=

1

n

⁢

{

f

⁡

(

Φ

i

,

θ

i

,

B

,

D

i

,

t

i

,

d

i

)

}

}

+

∑

i

=

1

q

⁢

{

∑

i

=

1

o

⁢

{

∑

i

=

1

m

⁢

{

f

⁡

(

Φ

i

,

θ

i

,

B

,

D

i

,

t

i

,

d

i

)

}

}

}

,

wherein § 1 is an accumulative dose distribution of the conformal therapeutic head, § 3 is an accumulative dose distribution of the focused therapeutic head, p is an indication of a number of the conformal therapeutic head, and n is an indication of a number of times of positional change of the radioactive source in the conformal therapeutic head, q is an indication of a number of the focused therapeutic head, o is an indication of a number of times of positional change of the focused therapeutic head, and m is an indication of a number of a radioactive sources in the focused therapeutic head.