Occam's broom* and the dirty DSB: cytogenetic perspectives on cellular response to changes in track structure and ionization density.

Occam's broom* and the dirty DSB: cytogenetic perspectives on cellular response to changes in track structure and ionization density. Int J Radiat Biol. 2020 Jan 23;:1-10 Authors: Cornforth MN Abstract Given equal doses, it is well-known that densely ionizing radiations are more potent in causing a number of biological effects compared to sparsely ionizing radiations, such as x- or gamma rays. According to classical models of radiation action, this results from differences in the spatial distribution of lesions along charged particle tracks. In recent years investigators have been barraged with the alternative narrative that this is instead due to 'qualitative' differences in the types of molecular lesions that each type of radiation produces. The present review discusses, mainly from a cytogenetic perspective, the merits and shortcomings of these seemingly contradictory viewpoints. There may be a kernel of truth to the idea that qualitative differences in the types of molecular lesions produced at the nanometer level affect RBE/LET relationships, but to ignore the fact that such differences result from longer-range spatial distributions of lesions produced along charged particle tracks is an unjustifiably narrow stance tantamount to employing Occam's Broom. Not only are such spatial considerations indispensable in explaining the impact of ionization density upon higher-order biological endpoints, particularly chromosome aberrations,...
Source: International Journal of Radiation Biology - Category: Radiology Tags: Int J Radiat Biol Source Type: research