MONTE-CARLO NUMERICAL TREATMENT OF ALPHA-PARTICLE SPECTRA FROM SOURCES BURIED IN BONE AND RESULTANT DOSES TO SURFACE CELLS

Purpose: To calculate the depth distribution of radioactive decays in bone by fitting a calculated alpha-particle energy spectrum to a measu red spectrum. The dose to bone surface cells is then calculated from t he depth distribution. Materials and methods: The spectra are calculat ed using Monte Carlo methods and a numerical depth distribution obtain ed by trial and error. Results: Alpha spectra for Po-210 and Ra-226 (p lus decay products) in bone were calculated and fitted to experimental spectra. The dose to bone surface cells was calculated using the nume rical technique and compared to previously published data. Conclusions : Alpha-particle spectra can be successfully fitted using this method, which gives a more realistic distribution of decays with depth than s imple surface and Volume models.