MRI Describes Mitigation of Radiation Necrosis

Xiaoyu Jiang¹, John A. Engelbach², Jeremy Cates³, Dinesh K. Thotala³, Robert E. Drzymala³, Dennis E. Hallahan³, Joseph JH Ackerman², Joel R. Garbow²

Radiation necrosis is a severe, but late occurring, injury to normal tissue, within and surrounding a radiation treatment field. Increases in vascular permeability (leakiness) and acute vascular apoptosis have both been suggested as possible causes of radiation necrosis. Bevacizumab may help to repair leaky capillaries and thereby mitigate radiation necrosis. Specific inhibitors of GSK-3β, a serine/threonine kinase, are known to ameliorate apoptosis. We have recently developed a novel mouse model of radiation necrosis using Gamma Knife irradiation. Here, we use small-animal MRI to measure the mitigation of radiation necrosis by bevacizumab and SB415286, an inhibitor of GSK-3β, in this mouse model.