A Monte Carlo simulation for Moving Light Source in Intracavity PDT

Area of Science:

• Medical Physics
• Oncology
• Biomedical Engineering

Background:

• Intracavity Photodynamic Therapy (PDT) requires precise light dose delivery for pleural lung cancer.
• The large surface area of the pleural cavity necessitates a moving light source for uniform dosimetry.
• Existing methods lack accurate simulation of light fluence and fluence rate throughout the entire cavity.

Purpose of the Study:

• To develop and validate a simulation method for modeling light fluence delivery in intracavity PDT using a moving light source.
• To enhance the accuracy of light dosimetry in complex anatomical spaces like the pleural cavity.
• To provide a tool for real-time visualization of dose distribution during icav-PDT.

Main Methods:

• Extended a Monte Carlo (MC) based light propagation solver to support moving light sources.
• Implemented a method (PEDSy-MC) using GPU CUDA for efficient computation.
• Validated the simulation against analytic solutions using a life-size lung-shaped phantom with multiple detectors.

Main Results:

• The PEDSy-MC method accurately simulates light fluence and fluence rate for intracavity PDT.
• Achieved simulation results within a 5% error of the analytic solution for multiple detectors.
• Demonstrated rapid computation times (under a minute to minutes) on a GPU-accelerated implementation.
• Developed a 2D/3D dose-cavity visualization tool for real-time inspection.

Conclusions:

• The developed simulation method (PEDSy-MC) provides accurate and efficient modeling of light delivery for intracavity PDT.
• This tool has potential for real-time navigation and dose assessment in clinical applications.
• The visualization tool will aid ongoing clinical trials at the Perlman School of Medicine (PSM).