Kundan Thind1,
2, Elaine Hegarty1, Albert P. Chen3, Heeseung Lim1,
2, Francisco Martinez1, Michael Jensen2, Eugene
Wong1, 4, Timothy J. Scholl1, Giles E.
Santyr1, 5
1Robarts
Research Institute, Western University, London, ON, Canada; 2Dept.
of Medical Biophysics, Western University, London, ON, Canada; 3GE
Healthcare, Toronto, ON, Canada; 4Dept. of Physics and Astronomy,
Western University, London, ON, Canada; 5Dept. of Medical Imaging,
Western University, London, ON, Canada
Sprague Dawley rats were irradiated using conformal radiotherapy to lower-medial right lung (18.5 Gy) to induce RILI (Radiation Induced Lung Injury). Hyperpolarized 13C-pyruvate was injected and regional lactate-to-pyruvate signal ratio was quantified day 10 and 15 (early RILI) post radiotherapy. Statistically significant increase in lactate-to-pyruvate signal ratio was observed in both left lung and right lung of irradiated animals compared to age matched healthy animals at day 10 and day 15. Onset of inflammation during early RILI was confirmed using histology. Lack of systemic spread of injury was confirmed by measuring blood lactate concentration.