Relative biological effectiveness (RBE) of 30 MeV electrons at varying depths in tissue

Using the stunting of vertebral growth of one-week-old inbred WHT/Ht mice as the biological test material and Fricke's ferrous sulphate method for dose measurements, the biological effectiveness of 30 MeV electrons relative to 250 kVp X rays has been found to be in the region of 0·82. No difference of statistical significance has been observed in the RBE of 30 MeV electrons given as single doses of 500 and 750 rads at per cent depth-dose levels varying from 100 to 10 in the case of the former and 100 to 15 in the case of the latter.