A flexible energy filter for ion beam therapy

Simple SummaryContent extracted from patent full text and abstract with AI.

This invention is a flexible energy filter designed for use in ion (especially proton) beam therapy, a form of cancer treatment. The filter consists of soft plastic (or water-equivalent material) sheets or cushions containing a layer of small metal particles (like spheres), which helps modify the energy profile of particle beams before they enter a patient's tissue. By placing the flexible filter directly on the skin, it spreads the Bragg peak (the point of maximum energy deposit in tissue), ensuring a more uniform distribution of radiation dose within the tumor while preserving sharp dose edges and minimizing beam scattering.

Use CasesContent extracted from patent full text and abstract with AI.

• Direct use in proton and ion beam cancer therapy to optimize radiation dosing profile.
• Customization of radiation dose distribution for tumors of varying thickness and location.
• Application in medical centers with gantry-based or fixed-line particle therapy installations for improved treatment planning and patient comfort.
• Expansion to other forms of hadron therapy where precise energy modulation and dose conformity are needed.

BenefitsContent extracted from patent full text and abstract with AI.

• Enables more precise control and broadening of the Bragg peak at low beam energies, enhancing treatment flexibility.
• Mechanical flexibility allows the filter to be placed directly on the patient's skin, minimizing lateral scattering and maintaining sharp dose boundaries.
• Improves homogeneity and conformity of the delivered radiation dose, potentially leading to better tumor coverage with reduced healthy tissue exposure.
• Reduces complexity and mechanical constraints compared to rigid range shifters or ridge filters, simplifying treatment setup and potentially lowering costs.
• Allows for finer energy modulation steps (e.g., 5 mm increments), streamlining treatment planning and execution across a wide range of beam energies.

Technical Classifications (CPCs)

Inventors & Applicants

Patent Abstract

It is the objective of the present invention to provide an energy filter that allows particularly at lower beam energies a determined spread of the beam energies in order to preserve the beam edges and to spread the Bragg peak at each individual beam energy. This objective is achieved according to the present invention by a flexible energy filter (2) for particle beam therapy, comprising: a) a cushion of plastic or water equivalent material (4) or a stack of at least two soft sheets of plastic or water equivalent material (4); and b) attached to the surface of the cushion or to the surface of a soft sheet of plastic or water equivalent material, or embedded in the cushion or embedded in the soft sheet or between the two soft sheets of plastic or water equivalent material (4), a layer (6) of a plurality of metal particles (8), preferably metal spheres; said layer (6) having a cross sectional area corresponding at least to a cross section of a beam scanning area at an outlet of the particle beam equipment prior to its entry into a tissue. This energy filter behaves similar to a ridge filter and spreads out the Bragg peak of a low energy proton beam (70-100 MeV) so that energy modulation of the beam can be done with steps of 5 mm in one go over the full range of 235 - 70 MeV. Due to its mechanical flexibility, the energy filter can be placed on the skin of the patient which minimizes the effect of scattering in the filter due to the short distance behind the layer of the plurality of metal particles within the flexible soft plastic sheet (the flap) to the skin of the patient.