Abstract #2712

Early Measures of ADC Response to Radiotherapy And/or Sunitinib in a Murine Intracranial Model of Human Glioblastoma Multiforme

Warren Foltz¹, Caroline Chung¹, Jesper Kallehauge¹, Kelly Burrell², Patricia Lindsay¹, David Jaffray¹, Gelareh Zadeh², Cynthia Mnard¹

¹Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario, Canada; ²Brain Tumor Research Centre, University Health Network, Toronto, Ontario, Canada

ADC can monitor early tumor response to cytotoxic therapy and predict clinical outcomes. This study monitored early ADC response and tumor growth following sunitinib and/or radiotherapy in a murine intracranial model of human glioblastoma multiforme. Imaging proceeded at 3-7 day intervals following base-line MRI and image-based stratification into treatment arms. RT trial arms demonstrated considerable early ADC elevation, and persistent elevation during growth delay. Sunitinib monotherapy maintained ADC below other arms, and constrained tumor growth. Control animals displayed moderate ADC elevation and earliest exponential tumor growth. Early ADC changes may be a useful biomarker of treatment response and growth delay.