Neutron Capture Beam Shaping to Reduce Fast Neutron Contamination
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Solution Overview
Problem
Conventional neutron capture therapy systems suffer from undesirable neutron flux and high fast neutron contamination, leading to unsatisfactory treatment effects and damage to normal tissues.
Innovation Solution
A neutron capture therapy system with a beam shaping assembly (BSA) that includes a fitting portion to reflect deviated neutrons back to the principal axis, utilizing materials with high elastic scattering cross section and low absorption cross section to enhance epithermal neutron flux and reduce fast neutron contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a proton beam is accelerated to form a neutron beam through interaction with a target, then neutrons are generated for treatment, but the obtained neutron beam has undesirable neutron flux and unduly high fast neutron contamination
Solution Approach 1:
The patent introduces a beam shaping assembly as an intermediary component between the neutron generation target and the treatment area. This assembly includes a first fitting portion that reflects deviated neutrons back to the principal axis, and a second fitting portion that further shapes the beam. These intermediary structures selectively redirect and filter neutrons, reducing fast neutron contamination while maintaining useful neutron flux for treatment.
Solution Approach 2:
The patent applies different functional zones within the beam shaping assembly: the first fitting portion handles neutron reflection and redirection, while the second fitting portion performs additional beam shaping and contamination reduction. Each portion is optimized for its specific function, creating local quality variations that collectively improve the overall neutron beam quality by addressing different aspects of neutron flux control at different locations.
2Reliability
If conventional radiotherapy is used to treat tumors, then tumor cells are killed, but a large number of normal tissues on the beam path are damaged
Solution Approach 1:
The patent employs boron-containing drugs that selectively accumulate in tumor cells, creating a local quality difference between tumor and normal tissues. When neutron beams irradiate the tumor area, only the boron-loaded tumor cells undergo intense local neutron capture reactions, producing high-LET radiation locally to kill tumor cells while minimizing damage to surrounding normal tissues that lack boron accumulation.
Solution Approach 2:
The beam shaping assembly acts as an intermediary that filters and shapes the neutron beam to deliver optimal flux to the tumor area while reducing contamination to normal tissues. The fitting portions selectively reflect and redirect neutrons to improve beam quality, ensuring that the treatment area receives the necessary neutron flux for effective tumor treatment while minimizing exposure of normal tissues to harmful fast neutrons.
3Ease of manufacture
If the first fitting portion is not attached to the particle transmission portion, then assembly is easier, but neutrons are lost in the gap and reflection effect is reduced
Solution Approach 1:
The patent divides the beam shaping assembly into multiple independent fitting portions (first fitting portion and second fitting portion) that can be separately manufactured and then assembled. Each portion can be optimized independently for its specific function, and the modular design allows for easier manufacturing and assembly while maintaining effective neutron reflection and beam shaping through proper interface design between segments.
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 system improves the quality of the neutron beam, increasing epithermal neutron flux and reducing fast neutron contamination, thereby enhancing treatment effectiveness while minimizing damage to normal tissues.
Implementation Method 1
utilizing materials with high elastic scattering cross section and low absorption cross section to enhance epithermal neutron flux
Implementation Method 2
the charged particles are capable of being interacted with the neutron generation portion through the particle transmission portion to generate neutrons
Implementation Method 3
The BSA is configured to improve quality of the neutron beam, such that an epithermal neutron flux for treatment can be increased
Data Source
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AI summary
A neutron capture therapy system. The neutron capture therapy system comprises: a charged particle generation device (100) used for generating charged particles; an accelerator (110) used for accelerating the charged particles; a neutron generation device (200) comprising a particle transmission part (210) and a neutron generation part (220) provided in a first end part (211) of the particle transmission part (210), wherein the charged particles can pass through the particle transmission part (210) and interact with the neutron generation part (220) to generate neutrons; a beam shaping body (300) having an accommodating cavity, wherein the accommodating cavity comprises a first surface (S1) and a second surface (S2) intersecting with the first surface (S1), and the first end part (211) is provided in the accommodating cavity; and a first fitting part (230) provided between the first surface (S1) of the accommodating cavity and the outer surface of the particle transmission part (210), wherein the first fitting part (230) is configured to at least surround part of the particle transmission part (210). According to the neutron capture therapy system, the first fitting part (230) is provided between the first surface (S1) of the accommodating cavity and the outer surface of the particle transmission part (210), so that deflected neutrons are reflected to a preset direction, and the epithermal neutron flux for treatment is improved.