Hybrid Stochastic Deterministic Optimization for Radiation Therapy Planning

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current radiation therapy planning methods face challenges in optimizing radiation source locations to effectively target tumors while minimizing damage to surrounding normal tissues, particularly due to the complexity of non-trivial constrained geometric optimization problems and the inefficiency of traditional computational approaches.

Innovation Solution

Combining stochastic optimization methods, such as particle swarm optimization (PSO), with deterministic optimization techniques like non-negative least squares and least-distance programming to model radiation sources as kinetic particles interacting with geometric volumes, allowing for the determination of optimal radiation source locations and trajectories that minimize damage to critical structures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional deterministic optimization algorithms are used to model all competing treatment goals and radiation source configurations, then the optimization problem can be solved systematically, but the computational complexity increases and treatment planning time extends

Engineering Contradiction:
Improveoptimization accuracyVSAvoidtreatment planning time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent segments the optimization process into two distinct phases: (1) a stochastic phase using particle swarm optimization to generate an approximate solution and identify promising regions in the search space, and (2) a deterministic phase using algorithms like non-negative least squares to refine the solution and satisfy all constraints precisely. This segmentation allows each method to play to its strengths, reducing overall computational time while maintaining optimization accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The stochastic optimization phase performs preliminary action by exploring the solution space and identifying promising regions before the deterministic phase begins. This preliminary exploration guides the subsequent refinement process, allowing the deterministic algorithms to focus computational resources on the most promising areas rather than searching the entire solution space, thereby reducing total planning time.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If the number of radiation sources and trajectories is increased to improve dose conformity to the tumor, then the radiation coverage improves, but the treatment complexity and number of implants required increases

Engineering Contradiction:
Improvedose conformityVSAvoidnumber of implants
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces traditional mechanical trial-and-error planning methods with a hybrid computational system that uses particle swarm optimization to simulate and evaluate numerous radiation source configurations virtually. This allows the system to identify the minimal set of implants needed to achieve dose conformity, avoiding unnecessary physical implants while maintaining treatment precision.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The optimization algorithm dynamically adjusts parameters such as radiation source locations, trajectories, and dosages to achieve optimal dose conformity. By continuously refining these parameters through the hybrid stochastic-deterministic approach, the system determines the minimum number of implants required to meet dose distribution goals, reducing device complexity while maintaining precision.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If stochastic optimization methods are used to explore the solution space, then the ability to find optimal solutions improves, but the computational time and resources required increases

Engineering Contradiction:
Improvesolution optimalityVSAvoidcomputational resources
Core Design Contradiction:
ReliabilityVSUse of energy by stationary object

Solution Approach 1:

The computational workload is segmented between stochastic and deterministic methods. The stochastic phase uses computational resources to explore the solution space and identify promising regions, while the deterministic phase uses fewer resources to refine the solution. This segmentation prevents the stochastic phase from consuming excessive computational resources by limiting its role to exploration rather than exhaustive optimization.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The stochastic optimization performs partial action by exploring only the most promising regions of the solution space rather than exhaustively evaluating all possible configurations. This partial exploration, guided by particle swarm intelligence, achieves sufficient solution optimality while consuming fewer computational resources than a complete stochastic search would require.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS10850122B2Optimization methods for radiation therapy planning
Publication Date: 2020.12.01 STC UNM
  • US10850122B2 patent drawing
  • US10850122B2 patent drawing
  • US10850122B2 patent drawing

AI summary

An optimization technique for use with radiation therapy planning that combines stochastic optimization techniques such as Particle Swarm Optimization (PSO) with deterministic techniques to solve for optimal and reliable locations for delivery of radiation doses to a targeted tumor while minimizing the radiation dose experienced by the surrounding critical structures such as normal tissues and organs.