Several preclinical studies using other imaging probes have quantitatively evaluated spatial overlap between in vivo tumor and fluorescence contrast agents 37, 38, 44, 45 or PET imaging agents 46, 47 in GBM orthotopic models, although differences in methodology preclude direct comparisons with the DSC values for the MMP-14 targeted peptide probes in the present studies. Here, MMP14 is linked to glioblastoma.