Experimental investigation of a fast Monte Carlo photon beam dose calculation algorithm

Area of Science:

• Medical Physics
• Computational Physics
• Radiation Oncology

Background:

• Accurate dose calculation is crucial for effective radiation therapy.
• Monte Carlo methods offer high accuracy but can be computationally intensive.
• Novel, faster algorithms are needed for clinical implementation.

Purpose of the Study:

• To experimentally verify the accuracy and efficiency of the XVMC code for photon beam dose calculations.
• To assess the impact of variance reduction techniques and material properties on dose distribution accuracy.
• To evaluate the potential of XVMC for routine clinical treatment planning.

Main Methods:

• Experimental validation of the XVMC code using measured depth dose curves and relative dose distributions.
• Modeling the treatment head with a point source and head scatter contribution.
• Utilizing utility software for model parameter determination from a single measured depth dose curve.
• Comparison of XVMC calculations with measurements from diamond detectors and film in various phantoms.

Main Results:

• XVMC and its simple beam model accurately reproduce measured relative dose distributions (within +/-2%) in homogeneous and inhomogeneous phantoms.
• Agreement between calculated and measured dose distributions is within experimental uncertainty for solid state phantoms.
• The code demonstrates short calculation times, making it suitable for clinical application.
• The developed utility software facilitates model parameter determination.

Conclusions:

• The XVMC code provides an accurate and efficient method for calculating photon beam dose distributions.
• Experimental verification confirms the code's reliability for clinical use.
• The combination of speed, accuracy, and an interface to commercial systems positions XVMC for routine treatment planning.