Design and application of 3D-printed stepless beam modulators in proton therapy

Area of Science:

• Medical Physics
• Radiation Oncology
• Biomedical Engineering

Background:

• Proton therapy requires precise beam modulation for accurate dose delivery.
• Current stepped modulator designs present limitations in dose uniformity and penumbra definition.
• Optimizing beam modulation is crucial for enhancing treatment efficacy and reducing side effects in proton eye therapy.

Purpose of the Study:

• To introduce and validate a novel stepless beam modulator design for proton therapy.
• To compare the performance of the stepless modulator against classic stepped designs.
• To assess the potential of the new design for improving dose distributions and biological equivalence.

Main Methods:

• Development and simulation of a stepless beam modulator design.
• Comparison of simulated depth dose distributions with classic stepped designs for various modulation widths.
• Fabrication of three modulator wheels using a Stratasys Objet30 3D printer.
• Simulation of bio-equivalence to Cobalt-60 (Co-60) cell kill.

Main Results:

• The stepless modulator design demonstrated improved depth dose uniformity compared to classic stepped designs.
• Simulations suggest a potential reduction in the distal penumbra width, requiring further experimental verification.
• A modulator wheel was successfully designed to achieve bio-equivalence to Co-60 cell kill.

Conclusions:

• The novel stepless beam modulator offers improved dose uniformity for proton therapy applications, particularly in proton eye treatments.
• Further research with precise measurements is needed to confirm the simulated improvements in distal penumbra width.
• The developed design shows promise for optimizing biological dose delivery and treatment outcomes in proton therapy.