Ion Beam Phantom for Bragg Peak Calibration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current radiotherapy systems using ions for cancer treatment face challenges in characterizing proton beams due to limitations in existing entrance dose monitors and portal imaging devices, which are sensitive to flux rather than radiation energy, making it difficult to accurately determine proton range and Bragg peak location.
Innovation Solution
A phantom system utilizing tissue-mimicking materials and an array of ion detectors to detect proton passage, allowing for the precise location of the Bragg peak and calibration of proton therapy machines, and enabling better characterization of CT images for treatment planning by equating CT numbers to proton-interacting materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If entrance dose monitors and portal imaging devices are used to characterize proton beams, then flux can be measured, but radiation energy and proton range cannot be accurately characterized
Solution Approach 1:
The patent introduces a water phantom as an intermediary medium between the proton beam and the detection system. The phantom contains embedded detectors that indirectly measure proton energy and range by detecting the Bragg peak deposition pattern in the water, rather than attempting to directly measure protons with conventional flux-sensitive devices.
Solution Approach 2:
The patent replaces conventional electronic detection systems (which measure flux) with a physical detection method using ionization chambers embedded in the phantom. This substitution allows measurement of energy deposition patterns rather than just particle flux, enabling accurate proton range and energy characterization.
2Measurement precision
If conventional detection systems are used, then device complexity remains low, but measurement precision for proton beam quality is insufficient
Solution Approach 1:
The phantom is segmented into multiple regions containing individual ionization chamber detectors at different depths. This segmentation allows the system to measure energy deposition at multiple points along the proton beam path, enabling reconstruction of the Bragg peak profile and accurate determination of proton range and energy.
Solution Approach 2:
The detection system is nested within the water phantom structure, with ionization chambers embedded at specific depths. This nested arrangement allows the detection system to be integrated into the phantom without adding external complexity, maintaining measurement precision while keeping the overall system compact and manageable.
3Manufacturing precision
If proton beams are used to improve dose conformity, then radiation dose can be precisely placed within the tumor, but exit dose from the beam cannot be monitored
Solution Approach 1:
The phantom is designed with detectors positioned at known depths before the proton beam delivery. This preliminary arrangement of detection elements at specific locations allows the system to predict and verify the Bragg peak position based on proton energy, providing reliable monitoring of dose placement accuracy without requiring complex real-time monitoring systems.
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 accurate characterization of ion beam energies and ranges, improving the precision of proton therapy by allowing for the calibration of radiation therapy machines and enhanced treatment planning, thereby optimizing dose distribution within tumors.
Implementation Method 1
a set of ion detectors spatially separated within the tissue-mimicking support to detect passage of heavy ions through the tissue-mimicking support
Implementation Method 2
the dose deposited by a proton beam is not uniform in homogenous tissue, but rises substantially, at the 'Bragg peak' just before the proton stops within the tissue
Data Source
AI summary
A phantom for heavy ion radiation therapy provides characterization of an ion beam that may enter but not exit from the phantom. The phantom may include multiple materials and multiple spatially dispersed ion detectors to obtain signals that may be fit to known beam curves to accurately characterize the location and other parameters of Bragg peak of a given ion beam within a patient.