Systems and methods for adjusting multi-leaf collimator

Patent metadata

Field	Value
Publication number	US-11730977-B2
Application number	US-202016750014-A
Country	US
Kind code	B2
Filing date	Jan 23, 2020
Priority date	Jan 23, 2020
Publication date	Aug 22, 2023
Grant date	Aug 22, 2023

Abstract

The present disclosure provides systems and methods for adjusting a multi-leaf collimator (MLC) in a treatment process according to a treatment plan or a portion thereof. The MLC may include at least one closed leaf pair in the treatment process. The method may include: for each of the at least one closed leaf pair, determining an offset for the closed leaf pair; and causing the at least one closed leaf pair to move based on the determined at least one offset before or during the treatment process.

First claim

What is claimed is:

1. A radiation treatment method implemented on at least one machine, each machine having at least one processor and at least one storage device for adjusting a multi-leaf collimator (MLC), comprising:
moving, according to a radiation treatment plan or a portion thereof, one or more leaves of the MLC, the MLC at least including one or more closed leaf pairs and one or more open leaf pairs, the radiation treatment plan including delivery of one or more treatment fractions, the moving including:
for each closed leaf pair of the one or more closed leaf pairs, determining an offset for each closed leaf pair based on a random value, to obtain one or more offsets corresponding to the one or more closed leaf pairs; and
causing the one or more closed leaf pairs to move based on the one or more offsets corresponding to the one or more closed leaf pairs, before or during the delivery of one or more treatment fractions.

2. The method of claim 1 , wherein the determining an offset for each closed leaf pair comprises:
designating the random value as the offset.

3. The method of claim 1 , further comprising:
generating the random value for each closed leaf pair by a random number generator.

4. The method of claim 1 , wherein the method further comprises:
generating the offset for each closed leaf pair before or at a beginning of at least one treatment fraction of the one or more treatment fractions.

5. The method of claim 1 , wherein at least one treatment fraction of the one or more treatment fractions includes a beam delivery, and the method further comprises:
generating the offset for each closed leaf pair before or at a beginning of the beam delivery in the at least one treatment fraction of the one or more treatment fractions.

6. The method of claim 1 , further comprising:
determining the offset for each closed leaf pair in a treatment planning process that generates the radiation treatment plan.

7. The method of claim 6 , further comprising:
after determining the offset in the treatment planning process, evaluating or adjusting one or more parameters of the radiation treatment plan based on a leakage distribution associated with a dose leakage of each closed leaf pair.

8. The method of claim 1 , wherein the offset of each closed leaf pair is no larger than a predetermined threshold, and the predetermined threshold is determined in a treatment planning process that generates the radiation treatment plan.

9. The method of claim 1 , wherein the causing the one or more closed leaf pairs to move comprises:
causing at least one closed leaf pair of the one or more closed leaf pairs to move, based on at least one offset corresponding to the at least one closed leaf pair, dynamically within at least one treatment fraction of the one or more treatment fractions.

10. The method of claim 1 , wherein at least one treatment fraction of the one or more treatment fractions include a beam delivery, and the causing the one or more closed leaf pairs to move comprises:
causing at least one closed leaf pair of the one or more closed leaf pairs to move, based on at least one offset corresponding to the at least one closed leaf pair, dynamically during the beam delivery in the at least one treatment fraction of the one or more treatment fractions.

11. The method of claim 1 , wherein the one or more offsets at least include a first offset and a second offset, and the causing the one or more closed leaf pairs to move comprises:
causing a first closed leaf pair of the one or more closed leaf pairs to move by the first offset in a first treatment fraction of the one or more treatment fractions; and
causing the first closed leaf pair of the one or more closed leaf pairs to move by the second offset in a second treatment fraction of the one or more treatment fractions.

12. The method of claim 11 , wherein the one or more offsets further include a third offset and a fourth offset, and the causing the one or more closed leaf pairs to move further comprises:
causing a third closed leaf pair of the at least one closed leaf pair to move by the third offset in a third treatment fraction of the one or more treatment fractions; and
causing a fourth closed leaf pair of the at least one closed leaf pair to move by the fourth offset in the third treatment fraction of the one or more treatment fractions.

13. The method of claim 1 , further comprising causing the one or more open leaf pairs to move according to the radiation treatment plan, wherein the causing the one or more closed leaf pairs to move comprises:
causing the one or more closed leaf pairs to move based on the one or more offsets corresponding to the one or more closed leaf pairs, synchronously or asynchronously with the moving of the one or more open leaf pairs.

14. The method of claim 1 , further comprising:
determining at least one closed leaf pair from the one or more closed leaf pairs that are uncovered by a jaw.

15. The method of claim 1 , further comprising:
determining, from the one or more closed leaf pairs, a first leaf pair whose state is changed from open to closed; and
after the first leaf pair is closed, causing the first leaf pair to move by a first offset of the one or more offsets.

16. The method of claim 1 , further comprising:
determining, from the one or more closed leaf pairs, a first leaf pair whose status is changed from closed to open;
during a period in which the first leaf pair is closed, causing the first leaf pair to move by a first offset of the one or more offsets;
prior to opening the first leaf pair, causing the first leaf pair to move to a prescribed position according to the radiation treatment plan; and
causing the first leaf pair to move from the prescribed position according to the radiation treatment plan.

17. The method of claim 1 , wherein each closed leaf pair of the one or more closed leaf pairs includes a gap between each closed leaf pair, and the causing the one or more closed leaf pairs to move comprises:
causing the one or more closed leaf pairs to move based on the one or more offsets corresponding to the one or more closed leaf pairs, so that a position of the gap between each closed leaf pair is adjusted by the offset corresponding to each closed leaf pair.

18. The method of claim 1 , wherein the MLC includes at least two layers of leaves, the at least two layers of leaves including a first layer and a second layer, the one or more closed leaf pairs including a first closed leaf pair and a second closed leaf pair, the first layer including the first closed leaf pair, the second layer including the second closed leaf pair, the method further comprising:
generating a first random value and a second random value independently;
causing the first closed leaf pair in the first layer to move based on the first random value; and
causing the second closed leaf pair in the second layer to move based on the second random value.

19. A radiation treatment system for adjusting a multi-leaf collimator (MLC) comprising:
a drive mechanism configured to drive one or more closed leaf pairs of the MLC to move according to a radiation treatment plan or a portion thereof, the MLC at least including the one or more closed leaf pairs and one or more open leaf pairs, the radiation treatment-plan including delivery of one or more treatment fractions; and
a controller configured to:
for each closed leaf pair of the one or more closed leaf pairs, determining an offset for each closed leaf pair based on a random value, to obtain one or mo

Assignees

• Shanghai United Imaging Healthcare Co Ltd

Inventors

• Stahl Johannes
• Aguilar Walter Arturo

Classifications

• A61N5/1036 Primary

  Leaf sequencing algorithms · CPC title

• A61N5/1045 Primary

  using a multi-leaf collimator, e.g. for intensity modulated radiation therapy or IMRT · CPC title

• A61N2005/1074

  Details of the control system, e.g. user interfaces · CPC title