Aim: To analyze the localization, distribution and effect of iodine nanoparticles (INPs) on radiation therapy (RT) in advanced intracerebral gliomas over time after intravenous injection. Materials & methods: Luciferase/td-tomato expressing U87 human glioma cells were implanted into mice which were injected intravenously with INPs. Mice with gliomas were followed for tumor progression and survival. Immune-stained mouse brain sections were examined and quantified by confocal fluorescence microscopy. Results: INPs injected intravenously 3 days prior to RT, compared with 1 day, showed greater association with CD31-staining structures, accumulated inside tumor cells more, covered more of the tumor cell surface and trended toward increased median survival. Conclusion: INP persistence and redistribution in tumors over time may enable greater RT enhancement and clinically relevant hypo-fractionated-RT and may enhance INP efficacy.
Keywords: distribution; fractionated radiation therapy; glioma radiotherapy; iodine nanoparticles; microlocalization; radiation therapy.