Radiotherapy Beam Scheduling for Cool-Down and Motion Control

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Solution Overview

Problem

Existing radiotherapy devices face inefficiencies in treatment delivery due to cool-down times, heat generation, and anatomical motion, leading to prolonged treatment sessions and reduced patient throughput.

Innovation Solution

A control scheme is implemented to optimize radiation delivery by scheduling delivery of radiation using a beam scheduling, scheduling delivery of radiation at different rates and incorporating cool-down periods based on operational parameters to ensure safe and efficient treatment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If radiation is delivered at a high radiation delivery rate to reduce treatment time, then productivity is improved, but heat generation increases causing the need for cool-down periods

Engineering Contradiction:
Improvetreatment delivery rateVSAvoidheat generation
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The patent implements periodic action by alternating between high radiation delivery rate periods (first time t1) and cool-down periods (second time t2). The control scheme schedules radiation delivery at high rates followed by controlled cool-down intervals, creating a periodic pattern that maximizes treatment efficiency while managing thermal load on the device components.

Inventive Principle:
Principle #19Periodic action

2Temperature

If cool-down periods are incorporated to manage heat generation, then temperature control is improved, but treatment time increases

Engineering Contradiction:
Improveheat managementVSAvoidtreatment session duration
Core Design Contradiction:
TemperatureVSLoss of time

Solution Approach 1:

The patent applies dynamics by making the radiation delivery rate variable rather than constant. The control scheme dynamically adjusts the delivery rate between high (first radiation delivery rate) and low/zero (during cool-down) based on real-time thermal conditions and treatment requirements, optimizing both temperature management and treatment time.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the operational parameters of the radiation delivery system by adjusting the radiation delivery rate as a controllable variable. The control scheme modifies this parameter over time, transitioning between different delivery rates to balance thermal management needs with treatment efficiency requirements.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If treatment time is reduced to minimize anatomical motion impact, then measurement precision is improved, but heat generation increases

Engineering Contradiction:
Improvetarget positioning accuracyVSAvoidheat generation
Core Design Contradiction:
Measurement precisionVSTemperature

Solution Approach 1:

The patent uses periodic action to deliver concentrated doses of radiation during high-delivery-rate periods that are synchronized with favorable anatomical positioning moments. By delivering maximum radiation intensity during brief windows when target positioning is optimal, the system achieves precise treatment while minimizing the overall time the beam is active, thereby reducing cumulative heat generation.

Inventive Principle:
Principle #19Periodic action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach allows for faster and more efficient delivery of radiation doses while ensuring the efficacy of the technical efficacy of the technical application, reducing the treatment time and reducing the impact of anatomical motion, thus improving the technical efficacy of the technical efficacy of the technical efficacy of the technical efficacy of the technical efficacy of the technical efficacy of the technical efficacy of the technical efficacy of the technical efficacy of the technical solution.

Implementation Method 1

a beam generation system, or other radiation source... configured to output radiation via a radiotherapy treatment beam

Methodology Applied
Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Implementation Method 2

The attenuation may be caused by absorption or by deflection (scatter) of photons within the beam, by the components of the cryostat

Methodology Applied
Scientific EffectAbsorption: Absorption (EM radiation)

Implementation Method 3

The attenuation may be caused by absorption or by deflection (scatter) of photons within the beam

Methodology Applied
Scientific EffectScattering: Scattering

Implementation Method 4

an 'inverse square law' applies for radiation, meaning that the dose delivery rate of the radiation beam is inversely proportional to the square of the distance from its source

Methodology Applied
Scientific EffectInverse square law:

Data Source

PatentEP4221830B1Controlling operation of a radiotherapy device
Publication Date: 2025.12.17 ELEKTA AB
  • EP4221830B1 patent drawingFigure 1
  • EP4221830B1 patent drawingFigure 2A
  • EP4221830B1 patent drawingFigure 2B

AI summary

Disclosed herein is a computer-implemented method of determining a control scheme for operating a radiotherapy device for delivery of a radiation dose via a radiotherapy treatment beam to a target. The radiotherapy device comprises a beam generation apparatus that is configured to output radiation via a radiotherapy treatment beam, and wherein operation of the radiotherapy device can be described using at least one operational parameter. The method comprises determining the control scheme by identifying a first time (t1) at which at least a first portion of the radiation dose is to be delivered at a first radiation delivery rate; and identifying a second time (t2) for the radiotherapy device to undergo a cool-down period, wherein during the cool-down period the radiation delivery rate is less than the first radiation delivery rate; wherein the control scheme is determined such that at least one criterion associated with the at least one operational parameter is met.