Figure 4. GNP administration in combination with RT improves survival in mice with advanced GBM tumors.

A. BLI of a representative mouse with advanced orthotopic GBM xenografts (radiance ∼10⁸ p/sec/cm²/sr) used for the survival study. B. Photograph of a brain and resected tumor 48 hours after intravenous injection of GNPs. Tumor shows darkened appearance due to extravasation due to EPR into the tumor. C. Survival data in mice with advanced orthotopic GBM treated with or without GNPs followed by mock-irradiation or given stereotactic RT (20 Gy). The right cerebral hemispheres of nude mice were initially implanted with 350,000 U251 cells, and tumors were allowed to grow until the measured radiance reached ∼10⁸ p/sec/cm²/sr (approximately 3–5 weeks post-implantation), at which point the mice were given their respective treatments (n = 5 for GNP+RT and n = 4 for control, GNP, and RT groups). Median and mean survival analysis were obtained with Kaplan-Meier analysis, and comparison between RT versus GNP+RT survival curves showed p = 0.011. Mean survival times are shown with 95% confidence intervals. N.S. in the figure indicates lack of statistical significance, while the asterisk (*) denotes that significance was reached (α = 0.05).