Fiducial-Based Patient Positioning for Particle Therapy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current patient positioning systems for particle therapy lack precision in aligning the irradiation target with the treatment system, leading to potential errors in tumor targeting due to inaccuracies in determining the location and orientation of the target relative to the treatment system.
Innovation Solution
A method and system that utilize fiducials to determine the location and orientation of the irradiation target relative to a reference coordinate system, allowing for precise alignment of the treatment couch to the isocenter of the particle therapy system, using imaging systems like CT or MRI to capture images of fiducials and anatomical landmarks, and a computer system to control the movement of the couch for accurate positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current patient positioning systems are used for particle therapy, then the treatment can be performed, but the precision in aligning the irradiation target with the treatment system is insufficient
Solution Approach 1:
The patent introduces fiducial markers as intermediary objects that are attached to or near the tumor target. These fiducials serve as mediators between the imaging system and the treatment system, enabling precise localization of the irradiation target through image registration and coordinate transformation. The fiducials provide known reference points that bridge the gap between planning images and real-time treatment positioning.
Solution Approach 2:
The patent creates a virtual copy of the patient's anatomy and tumor location through imaging systems (CT, MRI, or surface imaging). This digital replica is then registered with the physical treatment system through fiducial matching, allowing the treatment planning data to be accurately transferred to the treatment delivery system. The coordinate transformation process essentially copies the spatial relationships from the imaging domain to the treatment domain.
2Measurement precision
If fiducials are used to determine target location, then positioning precision is enhanced, but the system complexity increases
Solution Approach 1:
The patent employs fiducial markers that serve multiple functions: they act as reference points for image registration, provide localization markers for treatment positioning, and serve as verification points for quality assurance. This multi-functionality reduces the need for separate systems for each task, thereby limiting the increase in overall system complexity despite the enhancement in positioning precision.
3Ease of operation
If manual positioning methods are used, then the operation is simple, but the accuracy in directing the particle beam to the target is reduced
Solution Approach 1:
The patent implements a feedback loop where the imaging system continuously monitors the position of fiducial markers during treatment setup and delivery. The system compares the actual fiducial positions with the planned positions, calculates any deviations through coordinate transformation, and provides feedback for corrective positioning adjustments. This closed-loop feedback mechanism maintains ease of operation while significantly improving beam targeting accuracy.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An example treatment system includes: a treatment couch for holding a patient; fiducials associated with the patient; an imaging system to capture an image of the fiducials and of an irradiation target while the patient is on the treatment couch, where the image is captured in a treatment room where treatment is to be performed; a mechanism to move the treatment couch; and a computer system programmed to align locations of the fiducials to the fiducials in the image, and to determine a location of the irradiation target relative to a treatment system based on locations of the fiducials and based on the image. The movement of the treatment couch into a treatment position in the treatment room may be based on the location of the irradiation target.