Abstract 4438: Gold nanoparticle imaging and radiotherapy of brain tumors in mice.

Abstract

Abstract Aims: To test intravenously injected gold nanoparticles for X-ray imaging and radiotherapy enhancement of large, imminently lethal intracerebral malignant gliomas. Materials & Methods: ∼11nm gold nanoparticles were injected intravenously and brains imaged by microCT. Fifteen hours after an iv dose of 4 g Au/kg, brains were irradiated with 30 Gy 100kVp X-rays. Results: Gold uptake gave a 19:1 tumor-to-normal brain ratio with 1.5% w/w gold in tumor, calculated to increase local radiation dose by ∼300%. Mice receiving gold and radiation (30 Gy) showed 50% long-term (> 1 year) tumor-free survival, whereas all mice receiving radiation only died. In a second experiment using 35 Gy, long-term survival was 56% with AuNPs plus radiation versus 18% with radiation alone. Combining both experiments, the radiation plus AuNP treatments were statistically distinct from the radiation-only groups (p = 0.014). Conclusions: Intravenously injected gold nanoparticles cross the blood-tumor barrier but are largely blocked by the normal blood brain barrier, enabling high-resolution CT tumor imaging. Gold radiation enhancement significantly improved long-term survival compared to radiotherapy alone. This approach holds promise to improve therapy of human brain tumors and other cancers. Citation Format: James F. Hainfeld, Michael J. O'Connor, Daniel N. Slatkin, F Avraham Dilmanian, Henry M. Smilowitz. Gold nanoparticle imaging and radiotherapy of brain tumors in mice. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4438. doi:10.1158/1538-7445.AM2013-4438