title: Empirical equation for tissue-maximum ratios/scatter-maximum ratios for indirectly ionizing radiotherapy beams.
abstract: A six-parameter equation has been fitted to the tissue-maximum ratio/scatter maximum ration (TMR/SMR) tables for 60Co, 4-, 6-, and 10-MV photon beams as well as the 35 MeV d leads to Be neutron beam. The empirical equation has been shown to fit the 60Co tissue-air ratio/scatter-air ratio (TAR/SAR) data equally well. The TMR/SMR model was developed from a three-parameter equation designed to eliminate the graphical extrapolation of zero-field size TARs.
mesh_terms: D003037:Cobalt Radioisotopes / Q000008:administration & dosage*; D003201:Computers; D008433:Mathematics; D008962:Models, Theoretical; D011879:Radiotherapy Dosage; D012542:Scattering, Radiation
chemical_list: D003037:Cobalt Radioisotopes