3D printer-based novel intensity-modulated vaginal brachytherapy applicator: feasibility study

Area of Science:

• Medical Physics
• Oncology
• Biomedical Engineering

Background:

• Brachytherapy is crucial for gynecological cancer treatment.
• Current applicators may have limitations in dose modulation.
• Novel applicator design aims to improve treatment precision.

Purpose of the Study:

• To design and evaluate a novel high-dose-rate intracavitary applicator for gynecological brachytherapy.
• To achieve enhanced dose modulation capabilities.
• To ensure mechanical and dosimetric accuracy through rigorous testing.

Main Methods:

• 3D modeling and printing (polylactic acid filament) of the applicator and phantom.
• Mechanical tests: source-dwell positioning accuracy, reproducibility, and linearity.
• Dosimetric tests: point dose and 2D dose distribution validation against treatment planning system calculations.
• Measurements performed on a Varian GammaMed iX Plus unit using iridium-192 (192Ir).

Main Results:

• Mechanical tests showed source-dwell positioning accuracy ≤ 0.5 mm and linearity ≤ 1.5%.
• Treatment planning reproducibility met 97.7% gamma evaluation criteria (1 mm/1%).
• Dosimetric tests revealed a maximum point dose difference of 3.8% and >90% passing points in 2D analysis (3 mm/3%).

Conclusions:

• The designed novel brachytherapy applicator successfully met all quality control requirements.
• The applicator demonstrates feasibility for clinical application in gynecological brachytherapy.
• This innovation holds potential for improved dose modulation and treatment outcomes.