Adaptive Radiotherapy DVF Modification for Anatomical Variation
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Solution Overview
Problem
Current radiation therapy techniques face challenges in accurately delivering prescribed doses due to anatomical variations between planning images and actual treatment sessions, leading to potential mismatches and increased exposure to healthy tissues.
Innovation Solution
A processor-implemented method and system for adaptive radiotherapy that modifies the deformation vector field (DVF) to reduce vectors causing voxels to move away from target regions, transforming the dose distribution to generate a new treatment plan that ensures the target receives the prescribed dose while minimizing exposure to healthy tissues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the original treatment plan is delivered without modification, then the target may receive insufficient dose due to anatomical variations, but modifying the plan increases complexity and treatment time
Solution Approach 1:
The patent implements dynamic treatment plan adaptation by modifying the original radiation therapy plan based on deformation vector fields that map anatomical changes between planning and treatment phases. The system dynamically adjusts dose distribution parameters to compensate for interfractional anatomical variations, ensuring the target receives the prescribed dose despite anatomical changes.
Solution Approach 2:
The patent performs preliminary deformation analysis by comparing planning CT images with treatment CT images to generate deformation vector fields before delivering the radiation dose. This preliminary action identifies anatomical variations and pre-calculates the necessary plan modifications, allowing the treatment plan to be adapted in advance rather than requiring complex real-time adjustments during treatment.
2Measurement precision
If the deformation vector field is used to transform dose distribution, then anatomical variations are compensated, but the processing time and computational load increase
Solution Approach 1:
The patent segments the deformation vector field processing into distinct computational steps: (1) generating DVFs from image pairs, (2) applying DVF to transform dose distribution, and (3) generating modified treatment plans. This segmentation allows for optimized processing of each step and enables parallel computation where applicable, reducing overall computational time while maintaining precision in anatomical variation compensation.
3Object-affected harmful factors
If vectors in DVF are reduced to minimize healthy tissue exposure, then side effects are reduced, but the dose distribution transformation becomes more complex
Solution Approach 1:
The patent applies local quality modification to the deformation vector field by selectively adjusting vector magnitudes based on their impact on healthy tissue. Vectors that would cause excessive dose to healthy tissues are reduced in magnitude, while vectors critical for accurate target dose delivery are preserved. This localized adjustment optimizes the balance between target dose accuracy and healthy tissue protection without requiring complete reprocessing of the entire DVF.
Data Source
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AI summary
Techniques for use in adaptive radiotherapy and a treatment planning device are described. A method may comprise accessing two medical images representing a region of interest of a patient at different times. Each medical image can be segmented into a target region and at least one non-target region. The method may comprise accessing a deformation vector field including a plurality of vectors to map a respective voxel in a first medical image to a corresponding voxel in a second medical image. The method may comprise generating a modified deformation vector field and post-processing the modified deformation vector field to compensate for changes in the shape or size of the target region.