Density-based dose point kernel (DPK) scaling accuracy was investigated in various homogeneous tissue media.
Methods:
Using GEometry ANd Tracking 4 Monte Carlo code, DPKs were generated for 5, 8 MeV monoenergetic α particles and 223Ra, 225Ac, and 227Th. Dose was scored in 1 μm thick concentric shells and DPKs were scaled based on the tissue's mass density and compared with the water DPK.
Results:
Scaled kernels agreed within ±5% except near the Bragg peaks, where they differed up to 25%.
Conclusions:
The authors conclude that kernel scaling based on mass density of the transport medium can be utilized accurately up to 5%, excluding Bragg peak regions.
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