Analysis of the Time Relationship for the Interaction of X-ray-induced Primary Breaks in the Formation of Dicentric Chromosomes

Abstract
In split-dose experiments, the time relationship for the interaction of primary breaks in the formation of dicentric chromosomes was analyzed. Human peripheral lymphocytes were irradiated with a dose of 340 R of 220 kV X-rays split into 2 equal fractions separated by intervals up to 360 min. Assuming an exponential decline of the time-dependent quadratic component of the dose relation of dicentrics a theoretical formula was deduced. Fitting this formula to the empirical data a mean time of 110 min could be calculated in which primary breaks induced by both dose-fractions can interact to form dicentric chromosomes.