Abstract #3910

Mapping Changes in Lactate-To-Pyruvate Signal Ratio Using Hyperpolarized 13C-Pyruvate in Early Radiation Induced Lung Injury Post Conformal Radiotherapy of the Lung

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.