VMAT Treatment Plan Optimization Under MLC Leaf Motion Constraints
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional VMAT treatment plans for radiation therapy suffer from poor efficacy due to constraints on the motion of multi-leaf collimator leaves, leading to suboptimal radiation delivery.
Innovation Solution
A system and method for generating a VMAT treatment plan by optimizing segment parameters of control points, grouping beam angles into sets, and applying leaf motion constraints to improve leaf motion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional VMAT treatment plans are generated with standard optimization methods, then the treatment plan can be created, but the radiation delivery efficacy is poor due to constraints on MLC leaf motion
Solution Approach 1:
The patent segments the beam angles into at least two sets, where consecutive beam angles belong to different sets. The MLC leaf motion optimization is performed separately for each set, allowing independent optimization of segment parameters for each beam angle set. This segmentation approach resolves the contradiction by dividing the complex global optimization problem into smaller, more manageable sub-problems that can be solved more effectively despite leaf motion constraints.
2Productivity
If the number of optimization variables is large, then the treatment plan can cover all beam angles, but the optimization convergence is slow and execution time is long
Solution Approach 1:
By segmenting beam angles into multiple sets and optimizing segment parameters separately for each set, the patent reduces the number of variables in each optimization iteration. This allows for faster convergence of each sub-optimization problem while still achieving comprehensive coverage of all beam angles through the combination of multiple sets.
Solution Approach 2:
The patent performs preliminary segmentation of beam angles into sets before the optimization process begins. This preliminary action organizes the optimization variables in a way that facilitates faster convergence during the actual optimization, reducing the overall execution time by avoiding the need to optimize all variables simultaneously from scratch.
3Reliability
If MLC leaf motion constraints are applied strictly, then the treatment plan is feasible for delivery, but the radiation delivery efficacy is reduced
Solution Approach 1:
The patent applies different optimization strategies to different sets of beam angles. By treating each set locally with its own segment parameter optimization, the system can achieve better local feasibility compliance while maintaining overall treatment efficacy. Each local optimization can be tuned to respect leaf motion constraints specific to that beam angle set while maximizing the local dose delivery quality.
Data Source
AI summary
The present disclosure provides a system and method for generating radiation treatment plan. The method may include obtaining a plurality of beam angles of an arc for radiation treatment and preliminary segment parameters of control points associated with the plurality of beam angles. The method may also include grouping the plurality of beam angles into at least two sets so that each pair of two consecutive beam angles of the plurality of beam angles belong to different sets of the at least two sets, and determining the target segment parameters of the control points in each of the at least two sets by optimizing, based on a leaf motion constraint, the preliminary segment parameters of the control points associating with the plurality of beam angles. The method may further include generating a treatment plan based on the target segment parameters.