SUMMARY: This proposal will be the first comprehensive retrospective analysis of genomic, proteomic and dosimetric determinants of late radiation injury in prostate cancer. The investigators have assembled a broad array of expertise from the CCI PolyomX program (the only high throughput SNP facility in western Canada), the NCI/FDA Clinical Proteomics Program at Bethesda, MD, and the unique biophysical modeling capability of CBIAR researchers to reach these goals.