Rapid, Non-Invasive Radiation Bio-Dosimeter

The objective of this proposal is to develop a non-invasive radiation bio-dosimeter by employing a mobile breathalyzer to measure biomarkers of oxidative stress in the breath. The rationale for this research is that gamma radiation causes tissue injury, resulting in increased electron leak of reactive oxygen species from mitochondria to cytoplasm and increased lipid peroxidation of polyunsaturated fatty acids. This results in increased production of alkanes and methylated alkanes, which may lead to detectable changes in the composition of the breath as well as in cytokines in exhaled breath condensate. A completely safe, painless and non-invasive breath test could potentially provide a bio-dosimeter of exposure to radiation. In Phase I, this research will attempt to establish proof of principle by performing breath tests in human volunteers with cancer before and after radiotherapy. Breath samples will be collected with a breath collection apparatus, and then analyzed with gas chromatography and mass spectroscopy. If this pilot study demonstrates a significant increase in radiation-induced oxidative stress, a larger Phase II study will be performed with a field-portable breath test as a bio-dosimeter of exposure to radiation.