Static Ion Beam Compensator for FLASH Radiotherapy Dose Homogeneity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current ion-based radiotherapy methods, particularly in FLASH therapy, face challenges with traditional pencil beam scanning and rotating disk devices that are not feasible for short, high-dose rate treatments, necessitating a more efficient passive device for precise and homogeneous dose distribution.
Innovation Solution
A method for designing a compensating device with a disk-shaped structure and elongate elements, optimized using ray tracing and radiological path length concepts, allowing for a static device that modulates Bragg peaks and enables homogeneous dose distribution with a single energy level, suitable for both conventional and FLASH therapy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional pencil beam scanning with multiple energy levels is used, then homogeneous dose distribution is achieved, but treatment time becomes too long for FLASH therapy
Solution Approach 1:
The target volume is divided into multiple depth layers, with each layer treated by a specific energy level. The compensating device segments the ion beam into different energy components that deposit dose at different depths, enabling homogeneous dose distribution across the entire target volume in a single irradiation step without requiring sequential energy changes.
Solution Approach 2:
The compensating device is pre-designed with a specific thickness profile that encodes the desired depth-dose distribution. This preliminary design allows the system to achieve the effect of multiple energy levels simultaneously by using a single energy broad beam, eliminating the need for real-time energy modulation during treatment.
2Manufacturing precision
If a rotating disk is used to create spread-out Bragg peak, then homogeneous dose coverage is achieved, but the device becomes too complex and slow for FLASH therapy
Solution Approach 1:
Instead of using a rotating disk that physically moves to create dose modulation, the invention inverts the approach by using a static compensating device with a specific thickness profile. The spatial variation in compensator thickness directly translates to depth-dose distribution, eliminating the need for mechanical rotation and complex timing control.
Solution Approach 2:
The mechanical rotating disk system is replaced with a static compensating device that uses material thickness variation to achieve the same dose modulation effect. This substitution eliminates moving parts, reduces device complexity, and enables the extremely short treatment times required for FLASH therapy.
3Productivity
If a single energy broad beam is used, then treatment time is reduced for FLASH therapy, but homogeneous dose distribution cannot be achieved
Solution Approach 1:
The compensating device introduces local variations in material thickness across the beam path, creating localized dose modulation. Each region of the compensator with a specific thickness corresponds to a specific depth in the target, depositing the appropriate amount of energy locally to achieve homogeneous dose distribution throughout the entire target volume using a single energy broad beam.
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
Enables fast and reliable design of a passive compensating device that reduces the number of energy levels required, facilitating complex dose distributions and robustness against uncertainties, suitable for both conventional and FLASH therapy, with the ability to achieve full target coverage using a single energy level.
Implementation Method 1
use passive devices such as compensators to control the maximum range of the ions by providing an element of varying thickness made from a material that will attenuate the energy of the ions, thus shortening their path
Implementation Method 2
The point in which an ion deposits the main part of its energy is known as the Bragg peak, and is well defined near the end of the ion's trajectory
Data Source
AI summary
A compensating device for use in ion-based radiotherapy may comprise a disk with a number of protrusions may be placed in a radiation beam to affect the ions in the beam in different ways to create an irradiation field from a broad beam. This is particularly useful in FLASH therapy because of the limited time available or modulating the beam. A method of designing such a compensating device is proposed, comprising the steps of obtaining characteristics of an actual treatment plan comprising at least one beam, determining at least one parameter characteristic of the desired energy modulation of the actual plan by performing a dose calculation of the initial plan and, based on the at least one parameter, computing a shape for each of the plurality of elongated elements to modulate the dose of the delivery beam to mimic the dose of the initial plan per beam.