Radiotherapy Plan Interpolation via Collimator Constraints

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current radiotherapy treatment plan interpolation methods face challenges in directly interpolating between deliverable plans with significant dose distribution differences, leading to unwanted effects and inefficiencies due to the non-linear relationship between fluence and deliverable beam setups.

Innovation Solution

A method that interpolates between deliverable radiotherapy treatment plans by constraining the maximum difference in multi-leaf collimator and jaw positions, allowing for real-time navigation and dose recalculation without the need for a conversion step from fluence profiles, thereby ensuring a high-quality, immediate result.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If interpolation is performed between deliverable treatment plans with significant dose distribution differences, then real-time navigation and exploration of conflicting objectives is enabled, but unwanted effects occur due to the non-linear relationship between fluence and deliverable beam setups

Engineering Contradiction:

Improveability to navigate between treatment plansVSAvoidaccuracy of interpolated dose distribution

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent introduces an intermediary conversion step that transforms deliverable beam setups into fluence profiles before interpolation, and then converts back to deliverable setups. This intermediary fluence representation linearizes the relationship, enabling accurate interpolation while maintaining the reliability of the final deliverable plan.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the representation parameters from direct deliverable beam setups to fluence profiles. By working in the fluence domain during interpolation and then converting back, the non-linear relationship is resolved, allowing real-time navigation while maintaining dose distribution accuracy.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If a conversion step from fluence profiles to deliverable beam setups is performed after interpolation, then the interpolated plan becomes deliverable, but the dose distribution quality deteriorates and computation time increases

Engineering Contradiction:

Improvedeliverability of treatment planVSAvoidquality of dose distribution

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent performs the conversion to fluence profiles as a preliminary action before interpolation. By preparing the data in the fluence domain upfront, the subsequent interpolation and final conversion to deliverable setups maintains higher dose distribution quality and reduces overall computation time.

Inventive Principle:

Principle #10Preliminary action

3Loss of time

If direct interpolation of deliverable beam setups is performed, then computation time is reduced, but the non-linear relationship causes inaccurate dose distribution interpolation

Engineering Contradiction:

Improvecomputation time for interpolationVSAvoidaccuracy of interpolated dose

Core Design Contradiction:

Loss of timeVSMeasurement precision

Solution Approach 1:

The patent uses fluence profiles as an intermediary representation that linearizes the relationship between beam setups and dose distribution. This allows accurate interpolation while maintaining reasonable computation time, as the fluence domain operations are computationally efficient.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS10549120B2Method, a computer program product and a computer system for radiotherapy optimization

Publication Date: 2020.02.04 RAYSEARCH LAB

AI summary

An interpolation of deliverable radiotherapy treatment plans is facilitated by restricting the movement of the multi-leaf collimator leaves between optimization steps.