Radiation Therapy Tabletop Repositioning for Bragg Peak Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing radiation therapy techniques face challenges in accurately positioning the Bragg peak to maximize absorbed dose to focal tissues while minimizing dose to normal tissues, due to changes in patient position or internal tissue density during treatment planning, leading to prolonged correction times and increased burden on patients.
Innovation Solution
A radiation therapy system that includes a hold unit to maintain initial tabletop and irradiation conditions, with an identification unit to update tabletop movement information based on real-time voxel data, ensuring maximum focal coverage without altering irradiation conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If treatment plans are made several days before treatment administration to determine tabletop setting position and irradiation condition, then adequate dose can be applied to focal tissues, but patient's focus may be displaced during this period leading to inaccurate positioning
Solution Approach 1:
The system performs preliminary imaging and focus identification at the treatment administration stage itself, rather than relying solely on preliminary treatment planning several days earlier. The identification unit identifies the patient's focus position immediately before beam irradiation, ensuring the positioning information is current and accurate for the actual treatment moment.
Solution Approach 2:
The system implements a feedback mechanism where the identification unit continuously monitors and identifies the patient's focus position right before irradiation, and the control unit adjusts the tabletop setting position based on this real-time feedback. This closed-loop approach ensures that any displacement of the patient's focus is detected and corrected, maintaining accurate positioning despite time passage.
2Measurement precision
If tabletop setting position is corrected based on positional displacement of patient's bones or focuses checked via X-ray scan, then positioning can be adjusted, but it takes a long time for correction increasing treatment time
Solution Approach 1:
The system replaces conventional mechanical X-ray scanning methods with a more efficient imaging and identification system. The identification unit uses advanced imaging capabilities to rapidly acquire three-dimensional images and identify focus position without requiring time-consuming mechanical scanning and manual correction procedures.
Solution Approach 2:
The system performs focus identification and tabletop position determination immediately before beam irradiation in a streamlined sequence, rather than requiring separate correction steps. The control unit calculates the optimal tabletop setting position based on the identified focus position right before treatment, eliminating the need for time-consuming iterative corrections during treatment administration.
3Reliability
If treatment planning is performed several days before treatment administration, then adequate dose distribution can be calculated, but internal organs may change position due to food intake and body movement leading to dose mismatch
Solution Approach 1:
The system transitions from a static treatment planning approach to a dynamic one where the identification unit continuously identifies the patient's focus position immediately before each treatment session. The control unit dynamically adjusts the tabletop setting position based on the current focus position, allowing the system to adapt to any changes in internal organ position caused by food intake, body movement, or other physiological factors.
Solution Approach 2:
The system implements real-time feedback by identifying the patient's focus position right before beam irradiation and using this information to adjust the tabletop setting position. This feedback mechanism ensures that the dose distribution remains accurate even when internal organs change position between treatment planning and administration, as the system continuously adapts to the current anatomical configuration.
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 rapid maximization of absorbed dose to focal tissues while minimizing normal tissue exposure, reducing treatment time and patient burden by adapting to positional and density changes in real-time.
Implementation Method 1
a CT scan is performed on a patient to obtain voxel data, thus three-dimensionally identifying the shape and the position of a patient's focus in the body
Implementation Method 2
Particle beams, such as carbon ion beams, may decay in kinetic energy when passing through the patient's body, and then particle beams would be rapidly stopped when velocity drops to a certain value. Particle beams form a dose of beam distribution referred to as the Bragg peak near the stop point thereof to release energy.
Data Source
AI summary
A radiation therapy system includes a holding unit configured to hold first movement information for moving a tabletop such that a first position of a patient's focus identified by first voxel data matches an isocenter in a dose of a beam administered to the patient's focus, and an irradiation condition of the beam, which is set to maximize a focal coverage rate of the patient's focus irradiated with the beam at the first position; an identification unit configured to identify a second position of the patient's focus by second voxel data imaged immediately before emitting the beam; and an update unit configured to update the first movement information with second movement information to maximize the focal coverage rate at the position of the patient's focus without changing the irradiation condition.