An EGSnrc Monte Carlo-calculated database of TG-43 parameters.

Monte Carlo methods are used to calculate a complete TG-43 dosimetry parameter data set for 27 low-energy photon emitting brachytherapy sources (18 125I and 9 l03Pd). All Monte Carlo calculations are performed using the EGSnrc user-code BrachyDose. TG-43 dosimetry parameters, including dose rate constants, radial dose functions (with functional fitting parameters), and anisotropy data, are calculated with finer spatial resolution, greater range of distances, and smaller uncertainties than data currently available in the literature for many of these sources. In particular, for most of the seeds, this is the first time that anisotropy data have been tabulated at distances less than 0.5 cm from the source. These calculations employ the state-of-the-art XCOM photon cross sections, and detailed source geometries are modeled using Yegin's multigeometry package. This data set serves as a completely independent verification of the currently available dosimetry parameters calculated using other Monte Carlo codes, including MCNP and PTRAN. This report also describes the Carleton Laboratory for Radiotherapy Physics TG-43 Parameter Database, a publicly accessible web site (at http://www.physics.carleton.ca/clrp/seed_database/) through which all of the data calculated for this study can be accessed. Also available on the web site are descriptions of the methods and Monte Carlo models used in this study and comparisons of data calculated in this study with data calculated by other authors.