Heterogeneous-Body Radiation Dose Calculation Using Density-Scaled Kernels
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Solution Overview
Problem
Existing dose calculation methods for radiation therapy in heterogeneous bodies, such as lung tissue or bodies with air cavities, often overestimate the dose and are either too slow or too inaccurate, particularly when using convolution/superposition based methods.
Innovation Solution
A method and apparatus using a control circuit configured as a convolution/superposition based dose calculator with a three-dimensional energy-spreading kernel to scale the total energy released per mass based on the cross-sectional size and density of the radiation beam, adjusting energy release according to the beam's effective size and density, and convolving with a water kernel for accurate dose calculation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If convolution/superposition based dose calculation methods are used, then computation speed is improved, but dose accuracy deteriorates in heterogeneous bodies
Solution Approach 1:
The patent applies local quality by using density-specific scaling factors that vary throughout the heterogeneous body. Different regions (lung, soft tissue, bone) have different scaling factors applied to the energy-spreading kernel, allowing the calculation to adapt to local density variations and improve accuracy without sacrificing computational speed.
Solution Approach 2:
The patent changes parameters by introducing density-based scaling factors that modify the energy-spreading kernel. The scaling factor is determined by the density of the medium and the effective beam size, allowing the system to adjust the dose calculation parameters dynamically based on local conditions while maintaining the efficiency of convolution/superposition methods.
2Measurement precision
If other dose calculation approaches are used, then dose accuracy is improved, but computation time increases considerably
Solution Approach 1:
The patent segments the dose calculation process into distinct components: energy deposition calculation, density determination, and scaling factor application. By dividing the calculation into these manageable segments, the system achieves accuracy comparable to slower methods while maintaining the computational efficiency of convolution/superposition approaches.
Solution Approach 2:
The patent introduces a scaling factor as an intermediary element that bridges the gap between fast convolution/superposition methods and accurate dose calculation. This scaling factor, derived from density and beam size, acts as a mediator that corrects the dose calculation without requiring the computationally intensive approaches of traditional methods.
3Productivity
If traditional convolution/superposition methods are used without scaling, then computation speed is maintained, but dose overestimation occurs in low-density regions
Solution Approach 1:
The patent changes the calculation parameters by introducing density-dependent scaling factors that adjust the energy-spreading kernel. In low-density regions like lung tissue, the scaling factor reduces the calculated dose to compensate for overestimation, while maintaining computational speed through efficient parameter application.
Solution Approach 2:
The patent applies preliminary anti-action by pre-calculating scaling factors based on density and beam size before the actual dose calculation. This preliminary adjustment prevents dose overestimation in low-density regions from occurring in the first place, rather than correcting it afterward, thereby maintaining computational efficiency.
Data Source
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AI summary
These teachings facilitate the administration of therapeutic radiation to a heterogeneous patient volume using a radiation beam source. More particularly, these teachings provide for determining 201 a cross-sectional size of a radiation beam as corresponds to that radiation beam source and also for determining 202 density information corresponding to the aforementioned heterogeneous body. These teachings then provide for generating 203 a three-dimensional radiation dose calculation for the heterogeneous body using a control circuit configured as a convolution/superposition based dose calculator using a three-dimensional energy-spreading kernel. By one approach, these teachings provide for the calculator scaling total energy released per mass as a function of the cross-sectional size and energy of the radiation beam and the aforementioned density information.