EPID-Based Radiotherapy Verification with Segmented Semiconductor Detector
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Solution Overview
Problem
Current radiotherapy treatment verification systems lack the ability to characterize the accelerator beam and verify treatment concordance between planning systems and dose distribution in real-time, with inadequate spatial resolution and complexity in calibration, especially for 3D and axial plane measurements.
Innovation Solution
A system and method integrating a segmented semiconductor detector with a control and data acquisition system, allowing automated beam characterization and treatment verification using 2D and 3D gamma analysis, dose-volume histograms, and real-time dose mapping with improved spatial resolution and automation, incorporating accelerator log analysis for precise concordance evaluation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional water phantom dosimetry is used for beam characterization, then measurement accuracy is improved, but measurement time and operational complexity increase
Solution Approach 1:
The patent replaces the mechanical water phantom system with an electronic portal imaging device (EPID) based system. The EPID captures dose distribution images electronically, eliminating the need for physical water phantom measurements while maintaining dosimetric accuracy through image-based dose reconstruction algorithms.
Solution Approach 2:
The patent creates a virtual copy of the dose distribution by capturing images with the EPID and reconstructing the 3D dose map from these 2D projections. This virtual dose map serves as a digital replica that can be analyzed without physical measurements, significantly reducing measurement time.
2Productivity
If 2D array detectors are used for treatment verification, then real-time verification capability is improved, but spatial resolution deteriorates
Solution Approach 1:
The patent transitions from 2D array detector measurements to 3D dose reconstruction by acquiring images at multiple angles and reconstructing the full 3D dose distribution. This dimensional enhancement allows real-time verification while achieving sub-millimeter spatial resolution through tomographic reconstruction algorithms.
3Measurement precision
If EPID-based verification systems are used, then spatial resolution is improved, but system complexity and calibration difficulty increase
Solution Approach 1:
The patent implements self-calibration functionality where the system automatically determines its own geometric parameters and dose response characteristics by analyzing known phantom structures and comparing measured images with calculated reference images. This eliminates the need for complex manual calibration procedures while maintaining high spatial resolution.
4Measurement precision
If segmented semiconductor detectors are used for axial plane measurements, then spatial resolution is improved, but device complexity and cost increase
Solution Approach 1:
The patent makes the EPID system multi-functional by enabling it to perform both conventional 2D dosimetry and 3D axial plane dose reconstruction. This universal approach achieves high spatial resolution in all planes without requiring separate specialized detectors, thereby reducing overall system complexity and cost.
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 efficient characterization of the accelerator beam and verification of radiotherapy treatments with high spatial resolution and reduced uncertainty, optimizing clinical workflow and results by integrating direct measurements and log analysis for real-time validation.
Implementation Method 1
the dosimeter moves to the three different directions of the water phantom in order to take accurate measurements of the dose in different water depths
Data Source
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AI summary
The invention concerns a methodology for the automation and integration inside a same setting of the characterization of a beam accelerator, as well as the verification of a radiotherapy treatment based on the use of a detection medium and its control in a remote way.