Application

Radioactive tracer with improved plasma clearance for use as either a planar or positron emission tomography (PET) renal imaging agent.

Key Benefits

• Rapid renal excretion.
• Minimal localization at other body sites.
• More rapid blood clearance than current standard.
• Can be adapted for either standard planar or positron emission tomography (PET) imaging.

Market Summary

Renal nuclear scans are performed to investigate kidney function and structure. Following an intravenous injection, a renal radioactive tracer flows through the blood to the kidneys where it is extracted by the kidneys and excreted into the urine. Iodine-131 hippurate (¹³¹I-OIH) has long been the gold standard for measuring renal plasma flow and renal function but it has been replaced by technetium-99m mercaptoacetyltriglycine (^99mTc-MAG3) because of the superiority of ^99mTc as an imaging tracer compared to ¹³¹I. However, ^99mTc-MAG3 does not provide a direct measurement of renal plasma flow and shortages in the supply of ^99mTc have the potential to limit the availability of ^99mTc-MAG3. In contrast, positron emission tomography (PET) offers superior quantitation, is increasingly utilized in nuclear medicine imaging, and does not depend on the supply of ^99mTc. The dual purpose radioactive renal tracer provides a direct measure of effective renal plasma flow equivalent to ¹³¹I-OIH and can be used as either a planar (⁹⁹Tc-) or PET (fluorine-18) renal imaging agent.

Technical Summary

Researchers at Emory University have identified a renal imaging agent that can serve as a dual-purpose radioactive renal tracer that can be labeled with either technetium-99 (⁹⁹Tc) or fluorine-18 (¹⁸F). The advantage of this tracer is that it can be used on standard nuclear medicine cameras for imaging technetium-99m or adapted for a dedicated PET scanner by using fluorine-18. Studies show this new radiotracer has high in vivo metabolic stability, rapid renal excretion and high specificity for the kidney, reducing risk of uptake in other organs. This radioactive tracer has potential for improved renal imaging and is not dependent on the supply of technetium-99.

Development Stage

Both the ¹⁸F and ⁹⁹Tc versions of the tracer have been tested in animals and Phase I studies of the ⁹⁹Tc tracer are in progress.

Publications

Lipowska M et al. Nucl Med Biol. 2017; 47:48-55.
Klenc J et al. Bioorg Med Chem Lett. 2015;25(11):2335-9.
Taylor AT et al. J Nucl Med. 2013; 54(4):578-84.
Lipowska M et al. J Nucl Med. 2012;53(8):1277-83.