Combined electron emission effects on the biologically damaging efficiency of 125I.
OBJECTIVE
One important obstacle in modeling the biological damage of 125I lies in the collective effects of the emitted electrons. The huge number of possible different ways of atomic rearrangement causes a strong variability in the number and energies of the emitted electrons. The aim of this work is to tabulate, separately for each atomic rearrangement pathway, the absorbed doses and the single-strand breaks (SSB) probabilities for different size nanospheres of liquid water.


METHODS
A simple deterministic (non-stochastic) atomic rearrangement model of only 265 pathways is appropriate for modeling the electron-capture and internal conversion processes in 125I. The feasibility of the atomic rearrangement model is verified by comparing the SSB yield for ultrasoft X-ray sources with Lobachevsky's experimental data.


RESULTS
A linear equation is sufficient for describing the SSB probability as a function of the dose absorbed in a small volume surrounding the labelled nucleotide 125I-dC.


CONCLUSIONS
The application of a deterministic atomic rearrangement model to Auger electron emission spectra gives a new perspective to the study of low linear energy transfer (LET) radiation effects on DNA. The damages induced by point electron-capture (EC) sources and by macroscopic X-ray sources are compared.
Carles
A Grau
AG
Departamento de Física Atómica y Molecular Teórica, Instituto de Matemáticas y Física Fundamental, CSIC, Madrid, Spain. agrau@imaff.cfmac.csic.es
Malonda
A Grau
AG
D004247:DNA / Q000528:radiation effects*; D004249:DNA Damage; D004583:Electrons; D007457:Iodine Radioisotopes; D011336:Probability
D007457:Iodine Radioisotopes; D004247:DNA