Compact Proton Therapy Gantry with Reduced Source-to-Axis Distance
Solution Overview
Problem
Proton therapy systems are costly and large due to the high expense of multi-station systems, limited by the size and weight of dipole magnets and source-axis distance (SAD) requirements, making them unaffordable for smaller medical facilities and compromising treatment efficiency.
Innovation Solution
A compact lightweight gantry beamline with a reduced SAD of less than 2 m, using smaller and lighter magnets, optimized to maintain high beam delivery precision and full-range rotation, with a maximum beam energy of 220-230 MeV, allowing for a smaller footprint and reduced equipment costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional gantry beamline with SAD greater than 2m is used, then parallel beam translation at patient surface is achieved, but gantry size and weight become prohibitively large
Solution Approach 1:
The patent changes the fundamental parameter of SAD from conventional values greater than 2m to a reduced value between 0.5m and 1.5m. This parameter change enables the use of smaller, lighter dipole magnets while maintaining beam delivery precision through optimized magnet configurations and focusing elements.
Solution Approach 2:
The patent introduces a new spatial dimension by positioning the pencil beam scanning nozzle downstream of the final bend magnet, creating a compact arrangement that achieves parallel beam translation without requiring the traditional large SAD distance. This dimensional reorganization allows precise beam delivery in a reduced space.
2Adaptability or versatility
If multi-station single-cyclotron system is used, then cost distribution is improved, but overall system cost becomes prohibitively high for smaller facilities
Solution Approach 1:
The patent extracts the gantry from the traditional multi-station configuration and creates a standalone, compact proton therapy system that can operate independently. This extraction eliminates the need for multiple treatment stations sharing a single cyclotron, reducing overall system complexity and cost for smaller facilities.
Solution Approach 2:
The patent employs smaller, lighter dipole magnets with reduced magnetic field requirements compared to conventional systems. These lighter components reduce manufacturing costs, installation expenses, and facility requirements, making proton therapy accessible to smaller medical facilities.
3Force
If larger dipole magnets are used to achieve required magnetic field strength, then beam bending capability is improved, but manufacturing and installation cost increases
Solution Approach 1:
The patent changes the operating parameters of the dipole magnets by reducing the required magnetic field strength through the optimized beamline design and reduced SAD. This parameter change allows the use of smaller, more cost-effective magnets that are easier to manufacture and install while maintaining adequate beam bending capability.
Solution Approach 2:
The patent employs dynamic beam energy adjustment and optimized magnet positioning to achieve effective beam control with smaller magnets. By dynamically adapting the beam parameters and magnet configurations, the system maintains bending capability without requiring oversized permanent magnets.
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
The design achieves superior beam delivery performance, reduced equipment costs, and maintains treatment quality and precision, enabling efficient proton therapy in smaller facilities while minimizing the need for heavy shielding and large facilities.
Implementation Method 1
The first bend magnet 101 having an orbit bend angle of 45°, and the second bend magnet 102 having an orbit bend angle of 135°. Thus, the two bend magnets operate to bend a proton beam by 90° in total
Implementation Method 2
There are seven quadrupoles or focusing magnets 111-117 along the beamline 100
Implementation Method 3
a proton beam is generated and output from an accelerator, e.g., a cyclotron or a synchrotron, with a certain initial energy
Data Source
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AI summary
A compact lightweight gantry for a proton therapy system that has a source-to-axis distance (SAD) of less than (2) m and can deliver a proton beam of superior quality. The reduced SAD leads to reduced requirements on the maximum magnetic fields that can be generated by the bend magnets in the gantry beamline. Correspondingly, lightweight bend magnets can be used. The various components in the gantry beamline are optimized to achieve a beam spot size of approximately (4) mm sigma or less through a pencil beam scanning nozzle disposed downstream of the final bending magnet. In addition, the proton therapy system is configured to operate at a maximum beam energy in the range of (220-230) MeV.