Thorotrast and in vivo thorium dioxide: Numerical simulation of 30 years of α radiation absorption by the tissues near a large compact source

Most of the absorbed dose is concentrated in a 25-μm thick layer of tissue, adjacent to the source boundary. Fluctuations where a target region with a volume of 1 μm3 is hit by 3-5 α particles in a day or in a shorter period of time are relevant in a 1-10 μm thick layer of tissue adjacent to the source boundary, where their frequency is larger than the Poisson-law prediction.