Purpose Here we present a rapid whole body dose estimation approach applied to a clinical water phantom and whole body CT‐voxelized phantom, using electron dose kernels coupled with deterministic photon transport. This method yields fast, accurate whole body doses. Method and Materials A novel dose calculation methodology called EDK‐SN, or “Electron Dose Kernel‐Discrete Ordinates” rapidly estimates organ doses in a voxelized human phantom, accounts for in‐ and out‐of‐field doses using external photon beam therapy. We begin by solving the complete photon transport problem using parallel computing with the 3‐D discrete ordinates (SN) photon transport code PENTRAN. We then project pre‐computed (via Monte Carlo) voxel‐based Electron Dose Kernels (EDKs), mapping them to surrounding voxels via quaternion rotation, scaled by the magnitude of photon fluence from the SN calculation. An 8 MV flat‐weighted beam is incident on an 11×11×11 cm3 water phantom, and on a 15 year old human phantom, down‐sampled to 1×1×1 cm3 (60×27×167 voxels); a 6 MV Philips Elekta Linac photon spectrum has also been simulated. The percent depth dose was compared to clinical CC04 chamber measurement results; comparison of doses using the EDK‐Sn method and clinical treatment planning system (in field dose) will also be presented. Results The EDK‐SN technique has demonstrated independent agreement with Monte Carlo photon‐electron transport calculations for whole body dose. The EDK‐SN method yields a speedup of ∼8 (30 minutes versus 4+ hours) over the traditional parallel Monte Carlo, with <7% difference in different organs (smaller given stochastic uncertainties). The Monte Carlo simulated percent depth dose and clinical chamber PDD measurement agree within 10% among different field sizes. Conclusion The EDK‐SN method for high energy photon external beam dose calculations has been validated based on clinical external therapy beam calculations. This method will help to determine both in‐field and out‐of‐field radiation dose for radiotherapy.
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging