Energy-Modulated Radiation Therapy via X-Ray Spectral Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current radiation therapy techniques, such as IMRT and VMAT, face limitations in achieving steep dose gradients due to the physics of high-energy photons, making it challenging to further minimize damage to healthy tissues and maximize treatment efficacy, especially for geometrically complex targets.
Innovation Solution
The introduction of an electron-energy modulator in a linear accelerator system allows for dynamic adjustment of the x-ray spectral energy distribution, enabling the generation of lower photon-energy x-ray beams with high photon yields, which can be blended to optimize dose distribution and achieve steeper dose gradients, thereby improving target conformity and sparing normal tissues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If high-energy photon beams are used for deep penetration, then treatment depth is improved, but dose gradients become shallower making it difficult to spare normal tissues
Solution Approach 1:
The patent segments the x-ray beam into multiple discrete energy components using an energy-dispersive converter target. Instead of using a single high-energy beam, the system divides the beam into multiple energy bins (e.g., 6 MV, 4 MV, 2 MV) that can be independently controlled. This segmentation allows selective delivery of different energy levels to create steeper dose gradients while maintaining deep penetration capabilities through the highest energy components.
Solution Approach 2:
The patent dynamically changes the spectral energy distribution parameter of the x-ray beam by adjusting the electron beam energy and modulating the converter target. The system can shift the beam energy spectrum from high-energy (deep penetration) to lower-energy (steeper gradients) configurations, optimizing the trade-off between penetration depth and dose gradient steepness for different treatment scenarios.
2Manufacturing precision
If beam energy is reduced to achieve steeper dose gradients, then normal tissue sparing is improved, but penetration depth decreases limiting treatment of deep-seated tumors
Solution Approach 1:
The patent segments the x-ray beam into multiple discrete energy components using an energy-dispersive converter target. Instead of using a single high-energy beam, the system divides the beam into multiple energy bins (e.g., 6 MV, 4 MV, 2 MV) that can be independently controlled. This segmentation allows selective delivery of different energy levels to create steeper dose gradients while maintaining deep penetration capabilities through the highest energy components.
Solution Approach 2:
The patent uses a composite approach by blending multiple x-ray energy spectra (e.g., 6 MV, 4 MV, 2 MV) to create a composite beam with optimized properties. The composite spectrum combines the deep penetration capability of high-energy photons with the steep gradient formation of lower-energy photons, achieving both goals simultaneously through spectral superposition.
3Manufacturing precision
If multiple discrete beam angles are used in IMRT, then dose conformity is improved, but treatment time increases due to stopping irradiation between beam movements
Solution Approach 1:
The patent implements continuous irradiation during gantry rotation, eliminating the stop-and-go nature of conventional IMRT. The energy-modulated linear accelerator maintains continuous electron beam acceleration and x-ray generation throughout the arc rotation, allowing uninterrupted dose delivery. This continuous action reduces treatment time while maintaining dose conformity through real-time energy and intensity modulation.
Solution Approach 2:
The patent introduces dynamic energy modulation that changes continuously during the arc rotation. The electron beam energy and x-ray spectral distribution are dynamically adjusted as functions of gantry angle and time, enabling continuous adaptation of the beam properties to optimize dose delivery throughout the rotation without stopping irradiation.
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 enables more precise radiation delivery with steeper dose gradients, allowing for smaller treatment areas and better conformity to the target, while maintaining deep penetration capabilities, thus enhancing treatment efficacy and sparing sensitive structures.
Implementation Method 1
a high-energy (e.g., 6 MeV) electron beam generated in the LINAC may be directed onto an x-ray converter target, such as a sheet of tungsten or another heavy metal, to create, via interactions of the electrons with the target, a distribution of x-rays with energies up to the energy of the incident electrons
Implementation Method 2
The introduction of an electron-energy modulator in a linear accelerator system allows for dynamic adjustment of the x-ray spectral energy distribution
Data Source
AI summary
Described are devices, systems, and methods for modulating the spectral energy distribution produced by an x-ray source via control of the energy of the x-ray-generating electron beam, e.g., for energy-modulated radiation therapy or other purposes. In some embodiments, such energy modulation is achieved by an add-on device to a linear accelerator. Also disclosed are computational methods and computer program products for planning energy-modulated therapy.