Patients treated for prostate cancer may experience treatment related late effects that adversely affect quality of life and may prove life-threatening. The objective of this Phase I SBIR application is to determine the technical and commercial feasibility of a biomarker panel predictive of radiation mediated late effects in patients treated for prostate cancer. We will develop a metabolite signature of radiation responses in a cohort of patients undergoing stereotactic body radiation therapy (SBRT) for prostate cancer. Analysis of banked plasma samples will be correlated with clinical outcomes to identify markers of urinary and gastrointestinal late effects for validation in a larger clinical population to be proposed in a subsequent Phase II application. The Phase II effort will allow Shuttle Pharmaceuticals to advance its proposed commercialization plan and to raise capital to support validation clinical trials leading to FDA approval. Patients treated with stereotactic body radiation therapy (SBRT) for prostate cancers on an IRB approved protocol have banked clinical specimens and detailed monitoring of quality of life parameters. Sub-sets of these patients have developed urinary incontinence (UI), symptomatic urinary flare (USF), obstructed voiding symptoms/retention (UR) and radiation proctitis (RP). We have used high resolution mass spectrometry based metabolomics/lipidomic profiling to analyze this unique cohort of patient samples and propose here, to leverage our established analytical platform to advance product development and validation of a biomarker panel predictive of radiation toxicities. Metabolites in plasma from a cohort of 100 de-identified patients will be analyzed to develop a kit supporting metabolomic analysis to serve as a biomarker panel predictive of patient susceptibility for radiation late effects.