SUMMARY

With the recent interest in single fraction Stereotactic Body Radiation Therapy and the emerging prominence of the Rapid Arc radiotherapy technique capable of delivering a fast and accurate treatment, the in-field primary dose and out-of-field dose assessments are important. Currently, full physics Monte Carlo calculations for dose calculations have been regarded as a ‘gold standard’ for dose assessments of the target and OAR (organ at risk). However, these Monte Carlo calculations require very long computation times. The current treatment planning methods provide shorter calculation times, but issues such as heterogeneities and model-based parameter calculations may cause challenges and affect dose calculation accuracy. We propose to apply a new, fast convergence dose estimation approach leveraging parallel computing called EDK-Sn, “Electron Dose Kernel-Discrete Ordinates”. This novel dose calculation approach for heterogeneous, voxelized phantoms in a parallel computing environment uses hybrid electron dose kernels driven by linear Boltzmann (discrete ordinates) photon transport methods for deterministic radiotherapy dose calculations. The method has proven effective for fast and accurate computations of in-field whole body dose calculations benchmarked to Monte Carlo with isotropic monoenergetic sources. My thesis will focus on the development of an optimized EDK-Sn dose mapping calculation method, as well as study of the impact of different grids on accuracy of the dose calculation algorithm, combined with the spectrum using the real Varian Clinac head model from the GT RESL facility. New calculation results will be compared to real phantom measurement based on the GT Clinac iX machine, as well as to full physics photon-electron Monte Carlo calculation results.