Imaging of Gadolinium Spatial Distribution in Tumor Tissue by Laser Ablation Inductively Coupled Plasma Mass Spectrometry

Purpose: Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was utilized in postmortem imaging of gadolinium (Gd) spatial distribution in a mouse tumor model postadministration of PEGylated Gd liposomal nanoparticles. Procedures: PEGylated liposomal nanoparticles were formulated using a paramagnetic lipid incorporating Gd, in addition to a fluorescent lipid, and injected intravenously into Balb/C nude mice bearing IGROV-1 tumors. At postinjection (2 h), the tumors and selective organs were imaged by magnetic resonance imaging (MRI) and, after excision, by histology and LA-ICP-MS. Results: The presence of Gd within tumor tissue was confirmed by LA-ICP-MS and when correlated to histology was found to be prevalent in regions of higher vascularity. The presence of Gd in the kidneys was also confirmed. Conclusions: We have demonstrated, in a novel manner, the use of LA-ICP-MS for the spatial detection of Gd in tumor tissue. LA-ICP-MS is valuable in providing spatio-specific information of MRI contrast agents and more importantly Gd in tumor tissue.