Application of Monte Carlo technology to fast dose calculation of radiation therapy

The convolution core is the key factor to calculate dose with the convolution method in single-photon emission computed tomography (SPECT) diagnosis. The Monte Carlo (MC) technology was used to investigate the dose characteristic of the SPECT diagnosis with the radioactive isotope 131I. The expression of the 131I decay was given and was used to achieve the simulation of the electron and the photon of one decay of the 131I. The SPECT object is a spherical water phantom. The MC simulation results not only show that 131I can cure the hypothyroid caner and almost has no harm to the normal tissue, but also verify that the requirement of the self-adaption convolution core is met, for the relationship between the deposited energy and the areal mass is nothing to the density. The convolution core is gained by the MC simulation and is very useful to fast dose calculation.