For a thorough understanding of the molecular processes underlying tissue responses to radiation damage, the investigators propose a genomic analysis. Their working hypothesis is that normal organ toxicity will be associated with patient genetics as measured by single nucleotide polymorphisms (SNPs) in a select group of genes. The criteria for selecting SNPs will be based on a candidate gene approach, choosing genes implicated or demonstrated in DNA repair pathways and radiation-induced tissue damage/tissue homeostasis. Analysis of these data will use both statistically based bioinformatics approaches.