New calculation method for 3D dose distribution in tetrahedral-mesh phantoms in Geant4

Area of Science:

• Medical Physics
• Computational Dosimetry
• Radiation Oncology

Background:

• Tetrahedral-mesh (TM) geometry is promising for computational human phantoms.
• Calculating 3D dose distribution in TM geometry using Geant4's read-out geometry is computationally slow.
• This limitation hinders medical applications requiring rapid dose calculations.

Purpose of the Study:

• To develop a novel, rapid method for calculating 3D dose distribution in TM geometries.
• To evaluate the computational performance and accuracy of the new method compared to existing techniques.

Main Methods:

• Developed the Moving Voxel-based Dose-Distribution Calculator (MVDDC) method.
• Implemented TM cubic and human phantoms in Geant4.
• Irradiated phantoms with proton spot beams and compared MVDDC results with the read-out geometry method.

Main Results:

• No significant difference in dose distributions between MVDDC and the read-out geometry method.
• MVDDC simulations were approximately 1.4-2.7 times faster than read-out geometry simulations.
• The new method demonstrates comparable accuracy with enhanced computational speed.

Conclusions:

• The MVDDC method provides an accurate and significantly faster approach for 3D dose distribution calculations in TM geometries.
• This method overcomes the computational limitations of previous techniques, making it suitable for medical applications.
• MVDDC enhances the feasibility of using TM geometries for advanced dosimetry and treatment planning.