Imaging treatment efficacy of repeated photodynamic therapy in glioblastoma using CEST MRI

Glioblastoma (GBM) is hard to treat and has poor prognosis. Photodynamic therapy (PDT) is a promising treatment for GBM. Here, we detect the treatment efficacies of different PDT schemes (repeated (re-) and single (s-) PDT) on a rodent model of GBM using CEST MRI to monitor the molecular changes associated with tumor physiology and necrosis. Significant decreases in APT and rNOE signals were detected in the rePDT group as well as decreased proliferative activities in histology when compared with sPDT. This indicates that both APT and rNOE can be a reliable approach to assess PDT treatment efficacy against GBM.