Abstract #0661

CEST MRI for Monitoring Bacteriolytic Tumor Therapy

Guanshu Liu^1,2, Chetan Bettegowda³, Assaf A. Gilad^4,5, Michael T. McMahon^1,2, Kannie W. Y. Chan^2,5, Kenneth W. Kinzler³, Bert Vogelstein³, Jeff W. M. Bulte^2,5, Shibin Zhou³, Peter C. M. van Zijl^1,2

¹F. M. Kirby center, Kennedy Krieger Institute, Baltimore, MD, USA; ²Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; ³Ludwig Center, Howard Hughes Medical Institute & Sidney Kimmel Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA; ⁴Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; ⁵Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA

Bacteriolytic therapy has recently emerged as a promising approach for cancer therapy, in which anaerobic bacteria are utilized to selectively destroy the hypoxic cores of solid tumors. To facilitate its clinical translation, we sought to develop a non-invasive MR imaging method that is capable of monitoring infection with Clostridium novyi-NT. An inherent Chemical Exchange Saturation Transfer (CEST) signal at 2.6 ppm from the water proton signal was found in cultures of this bacterium in vitro. Using this signal, we were able to detect the germination of the anaerobic bacteria in vivo.