News | June 09, 2014

Enzyme-inhibition Could Revolutionize Molecular Imaging

Oncologic imaging just got better with a naturally occurring compound that protects injected radiopeptide imaging agents from enzymatic degradation in the body

June 9, 2014 — The prominent role a single enzyme plays in cancer imaging has eluded researchers for years, but not anymore. This discovery could pave new avenues in nuclear medicine. The enzyme, called neutral endopeptidase (NEP), has a way of breaking down most radiopeptide imaging agents in the body. Researchers have developed an elegant new concept that improves molecular imaging, according to study results presented during the Society of Nuclear Medicine and Molecular Imaging’s 2014 Annual Meeting.

The sneaky enzyme has evaded studies with peptide tracers until now because it dwells not in tested blood serum but along the walls of blood vessels and other tissues. In order to combat the degradation of circulating radiopeptides, researchers co-injected a NEP inhibitor called phosphoramidon, derived from bacteria, at the same time as an agent for imaging with single photon emission computed tomography and computed tomography (SPECT/CT). They then applied this method of enzyme inhibition in multiple imaging studies involving a range of radionuclide and peptide counterparts. The results of this research showed consistent success — up to 40 times the circulating radiopeptides when protected with phosphoramidon, compared to unprotected controls. This means the simple co-injection of an enzyme inhibitor promotes dramatically improved bioavailability and metabolic stability of radiopeptide imaging agents leading to higher uptake of the agent within targeted tumors and therefore better cancer imaging.

Oncologists have long sought a powerful ‘magic bullet’ that can find tumors wherever they hide in the body so that they can be imaged and then destroyed,” said Marion de Jong, Ph.D., a principal researcher for this study conducted at Erasmus Medical Center in Rotterdam, The Netherlands in cooperation with NCSR ‘Demokritos’ Athens, Greece. “Following this innovative approach, we have been able to induce, for the first time, an impressive improvement in the level of circulating and viable radiopeptides, leading to a spectacular increase in tumor uptake. Enzyme-inhibition in the body could translate into higher diagnostic sensitivity and improved therapeutic efficacy of radiopeptide drugs in cancer patients.”

Not only were circulating radiopeptides increased in small animal models of varying tumor types, but the accumulation of radiopeptides also peaked at 14 times that of controls, which had not been treated with enzyme-inhibiting phosphoramidon. These results were clearly visualized by SPECT/CT imaging.

For more information: www.snmmi.org

Related Content

Videos | SPECT-CT | December 12, 2018
This is a walk around of the new Spectrum Dynamics Veriton SPECT-CT nuclear imaging system introduced at the 2018 ...
Spectrum Dynamics Sues GE for Theft, Misappropriation of Trade Secrets and Unfair Competition
News | SPECT Imaging | December 06, 2018
Single-photon emission computed tomography (SPECT) cardiac imaging company Spectrum Dynamics filed a lawsuit Dec. 6,...
Subtle Medical Receives FDA Clearance, CE Mark for SubtlePET
Technology | PET Imaging | December 05, 2018
Subtle Medical announced 510(k) clearance from the U.S. Food and Drug Administration (FDA) to market SubtlePET. Subtle...
Mirada Medical Joins U.K. Consortium Exploring Healthcare AI
News | Artificial Intelligence | December 04, 2018
Mirada Medical, a leading global brand in medical imaging software, will form part of an artificial intelligence (AI)...
GE Healthcare Recalls Millennium Nuclear Medicine Systems
News | Nuclear Imaging | November 15, 2018
GE Healthcare announced it is recalling its Millennium Nuclear Medicine Systems due to an incident in which the the top...
Artificial Intelligence Predicts Alzheimer's Years Before Diagnosis
News | Neuro Imaging | November 14, 2018
Artificial intelligence (AI) technology improves the ability of brain imaging to predict Alzheimer’s disease, according...
Researchers Awarded 2018 Canon Medical Systems USA/RSNA Research Grants
News | Radiology Imaging | November 13, 2018
The Radiological Society of North America (RSNA) Research & Education (R&E) Foundation recently announced the...
Subtle Medical Showcases Artificial Intelligence for PET, MRI Scans at RSNA 2018
News | Artificial Intelligence | November 13, 2018
At the 2018 Radiological Society of North America annual meeting (RSNA 2018), Nov. 25-30 in Chicago, Subtle Medical...
University of Missouri Research Reactor First U.S. I-131 Supplier in 30 Years

MURR is the only supplier of I 131 in the United States and the first U.S. supplier since the 1980s. Image courtesy of University of Missouri

News | Radiopharmaceuticals and Tracers | November 13, 2018
The University of Missouri Research Reactor (MURR) recently shipped its first batch of Iodine-131 (I-131), a...
MEDraysintell Projects Increasing Mergers and Acquisitions in Nuclear Medicine
News | Nuclear Imaging | November 07, 2018
With the recent announcement by Novartis to acquire Endocyte , interest from the conventional pharmaceutical industry...