Monte Carlo Simulation

The Monte Carlo (MC) method is a method of approximately solving mathematical and physical problems by the simulation of random variables. The use of the MC method in modeling particle transport provides a level of extreme accuracy in the determination of radiation doses received by a patient during a radiotherapy treatment. At the Vancouver Island Centre (VIC), we have a dedicated 12-node Linux cluster running the BEAMnrc Monte Carlo system for a wide variety of MC applications.

Virtual accelerator pptimization

The development of advanced techniques to fine-tune the output our linear accelerator models has provided UVic/VIC with some of the most accurate medical accelerator mod-els in the world. This accuracy translates into all our MC applications from MC based inverse treatment planning to the verification of treatment plan dose calculations.

Treatment plan verification

We have developed a streamlined method of verifying clinical Intensity Modulated Ra-diotherapy (IMRT) plans using MC. This application has shown the potential to increase the number of patients able to benefit from IMRT by increasing the body sites we are able to safely treat. The VIC has also developed a software module to model random patient setup error in MC simulations. This module hopes to help quantify the impact that setup error has on delivered dose distributions.

Inverse treatment planning with Monte Carlo

Many recent studies are uncovering inaccuracies in dose calculations performed by common superposition and convolution dose calculation algorithms in the presence of tissue inhomogeneities. Research conducted at UVic/VIC has developed a method of generating the small beam elements or "beamlets" needed for inverse treatment planning using BEAMnrc. The ability to generate these MC beamlets has opened the door for the use of precise MC dose calculations in clinical inverse IMRT treatment planning. At the VIC, we are currently developing methods to implement MC beamlet calculations in Direct Aperture, Fluence Based, and Matrix Inversion based inverse treatment plan optimization.

Evaluation of commercial treatment planning system dose calculation algorithms

The VIC is among the world leaders in MC research. The success of this research at the VIC has attracted commercial treatment planning computer system manufacturers to choose the VIC as a testing ground for evaluating the latest dose calculation algorithms.