Jinyuan Zhou1, Erik Tryggestad2, Zhibo Wen1, Bachchu Lal3, Tingting Zhou1, Rachely Grossman4, Kun Yan1, Silun Wang1, De-Xue Fu5, Eric Ford2, John Laterra3, Peter C.M. van Zijl1
1Department of Radiology, Johns Hopkins University, Baltimore, MD, United States; 2Department of Radiation Oncology, Johns Hopkins University, Baltimore, MD, United States; 3Department of Neurology, Kennedy Krieger Institute, Baltimore, MD, United States; 4Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, United States; 5Department of Oncology, Johns Hopkins University, Baltimore, MD, United States
We show that it is possible to differentiate between glioma and radiation necrosis using the amide proton signals of endogenous cellular proteins and peptides as imaging biomarker. Using a radiation necrosis model (dose, 40 Gy; area, 10x10 mm2) and a SF188/V+ human glioma model in rats, tumors and radiation necrosis had similar conventional MRI features. However, gliomas were consistently hyperintense on amide proton transfer (APT) images, while radiation necrosis (observed about six months post-radiation) was hypointense to isointense. APT MRI as an imaging biomarker for tumor presence provides unique visual information for assessing active tumor versus treatment-related injury, such as radiation necrosis.