Tantalum as a novel CT Contrast Agent for new capabilities in tumor detection, staging and response assessment

• Applicant: Dr. Theresia Aschauer
• Subject Area: Nuclear Medicine, Radiotherapy, Radiobiology
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 533189629

The evolution of (multi)spectral CT imaging in the form of fast clinical dual-energy CT has been promising in many regards with relevant potential for new contrast agents: it enabled contrast material to be differentiated from other radiodense materials, improved lesion detection in contrast-enhanced scans, and changed the way that existing iodine and barium contrast materials are used in clinical practice. More profoundly, these spectral CT capabilities would be even more impactful with the development of contrast materials designed to complement the existing clinical iodine- and barium-based agents. New biocompatible contrast materials will expand the diagnostic power of spectral CT imaging without penalties in radiation dose or scan time. Defined research need is the evaluation of novel intravenous contrast agents to overcome limitations of available iodine-based contrast agents and to reimagine their potential that currently remains unexploited. Research will address (1) safety and (2) efficacy in defined use cases and latest CT platform technologies, including DECT and PCCT. These studies are essential for further evolution of this contrast agent (TaCZ) and streamline translation towards approval. The proposed tantalum-based CT contrast agent is a blood pool agent with significantly improved vascular and parenchymal conspicuity that is sustained over time. Meanwhile, the superior contrast enhancement provided by the tantalum-based contrast agent could help reduced required contrast volume at injection, which may be valuable in patients with acute and chronic heart failure, volume overload or kidney disease. We also foresee a significant impact on patients who have contraindications that prevent the safe use of iodine-based contrast agents, including allergy and hyperthyroidism. The overall objective of this project is to evaluate the efficacy of a novel intravenous (i.v.) tantalum-based nanoparticle (TaCZ = carboxybetaine zwitterionic tantalum oxide) CT contrast agent for detection and monitoring of hepatic and extra-hepatic lesions in oncologic CT imaging. The specific aims of this research project are: - Evaluate the detectability of hepatic lesions in a VX2 tumor model in the New Zealand rabbit using i.v. TaCZ compared to a conventional iodine contrast agent (Iopromide) in different contrast phases of a dual-layer dual-energy CT. -Evaluate the conspicuity of extra-hepatic lesions in paraspinal muscle using i.v. TaCZ compared to iodine contrast agents (Iopromide) in different contrast phases of a dual-layer dual-energy CT. - Evaluate the potential of TaCZ to improve monitoring of an anti-VEGF-therapy in dynamic contrast enhanced CT studies compared to iodine contrast agents.

• DFG Programme: WBP Fellowship
• International Connection: USA
• Host: Professor Dr. Benjamin M. Yeh