Abstract 85: Noninvasive imaging of tumor hypoxia during radiation-induced tumor vascular disruption

Abstract

Purpose Tumor vascular targeted gold nanoparticles induce tumor vascular disruption when combined with external beam radiation therapy. Although effective in suppressing tumor growth and improving progression-free survival, tumor hypoxia may be a potential challenge in this anti-vascular therapy. Here, we investigate, the dynamic changes in tumor hypoxia pre- and post-radiation therapy using a gold nanoparticle-based tumor vascular disrupting agent. Materials and methods 4-6 weeks old female nude-FOXn1 mice were subcutaneously inoculated with human A549 cells (~3×106) into the left flank. Functionalized gold nanoparticles (AuNP) were used to target the tumor blood vessels and tumor vascular disruption was induced via radiation. 10 Gy radiation treatment was delivered using a clinical radiation beam (6 MV) and HypoxiSense680 based in vivo fluorescence imaging was performed to visualize changes in tumor hypoxia at 24 h, 48 h and an extended period of 10 days. Tumor hypoxia was confirmed via immunohistochemistry. Mice were divided into four treatment groups: control, AuNP only, IR only, and AuNP+IR. Following treatment, tumor progression and overall survival was measured. Further analysis of nanoparticle biodistribution and toxicity were accessed using TEM Imaging, IC-PMS, and immunohistochemistry. Results Longitudinal changes in tumor hypoxia were observed in all radiation-based treatment conditions. Combining gold nanoparticle and radiation resulted in an increase in tumor hypoxia at 48 h (p Conclusions Noninvasive imaging showed that AuNP+IR results in a transient increase and subsequent decline in mean tumor hypoxia, leading to substantial tumor regression and an overall increase in tumor survival. High radiation-induced vascular damage may lead to better tumor reduction and prolonged survival in the human non-small cell lung cancer model. Citation Format: Olivia J. Kelada, Sijumon Kunjachan, Needa A. Virani, Alexandre Detappe, Jennifer Hayashi, Thomas Ireland, Douglas E. Biancur, Rajiv Kumar, Srinivas Sridhar, Mike Makrigiorgos, Ross I. Berbeco. Noninvasive imaging of tumor hypoxia during radiation-induced tumor vascular disruption [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 85.