Abstract
The combination of GNPs exhibiting the enhanced permeation and retention effect, a property of nanoparticles between 10-100nm that cause them to accumulate inside tumors due to the tumors’ leaky vascular and poor clearance, for tumor targeting and possessing a high atomic number to increase the local dose deposition around the GNPs make them an ideal agent in cancer therapy. However, poor elimination of off-target GNP accumulation by the reticuloendothelial system significant concerns over long-term side effects that have hindered GNPs’ clinical translation. To pave the way for clinical translation of GNPs, biodistribution optimization in GNP design and a clear understanding of in vivo GNP radiosensitization mechanisms are essential. Preclinical studies in small animal irradiators equipped with various imaging modalities offer a clinically relevant environment for radiobiology studies on GNPs. Furthermore, x-ray fluorescence computed tomography (XFCT) has garnered significant attention in recent years as a high resolution, high sensitivity imaging modality for quantitative imaging in benchtop small animal irradiator studies with GNPs. To guide future investigation of GNPs with XFCT, we demonstrated the capabilities of multimodal imaging alongside XFCT to monitor in vivo GNP biodistribution for prostate cancer targeted GNPs and to assess heterogenous intratumoral GNP distribution influences on tumor response to radiation therapy.