A Monte Carlo derivation of parameters for use in the tissue dosimetry of medium and low energy nuclides

A technique for deriving the tissue-absorbed dose resulting from the use of a selection of nuclides commonly employed in brachytherapy is given. The various parameters required have been obtained from a Monte Carlo computer program which derives tissue attenuation data from the equations of White and Fitzgerald (1977a). Some inconsistencies in the data used to obtain the equations are noted and corrected. Useful results are presented and, in particular, possible dosimetric errors associated with the clinical use of 125I seeds are highlighted.