FIG. 5.

Therapeutic effect of radiovirotherapy in glioblastoma xenograft mouse models. (A) Mice (n=8 per group) with established right flank U251 tumors received two injections with MV-NIS or matched UV-inactivated control (4×10⁶ TCID₅₀ total dose). Three days later, they were treated with 1 mCi of ¹³¹I through intraperitoneal injection or PBS only. Mice in the radiovirotherapy group had significantly longer survival (p=0.0003) over mice treated with MV-NIS or ¹³¹I alone. (B) Mice (n=8 to 10 per group) with established GBM43 orthotopic brain tumors received four treatments starting 8 days post implantation with MV-NIS or matched UV-inactivated control (1.8×10⁶ TCID₅₀ total dose). The radiovirotherapy group received ¹³¹I intraperitoneally 3 days after the last viral treatment, with the timing determined based on imaging studies. MV-NIS treatment extended the survival of the animals (p=0.0004) as compared with the UV-MV-treated control group, and addition of ¹³¹I significantly extended survival of the animals as compared with the MV-NIS-only treated group (p=0.039). (C) Sections from brains from GBM43-implanted mice were stained with H&E: extensive syncytia formation was observed (arrow). Original magnification, 200×. (D) In situ hybridization for MV N mRNA is positive, confirming active viral replication in tumors.