Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

PET radiotracer design for monitoring targeted immunotherapy

10.04.2017

In an article published in the April issue of "The Journal of Nuclear Medicine," researchers at Stanford University in California provide a template for assessing new positron emission tomography (PET) radiotracers that can accurately identify molecules in cancer cells that prevent the immune system from attacking the cancer.

A drug that blocks a cancer's inhibitory checkpoint molecules is called an immune checkpoint inhibitor and this form of immunotherapy has emerged as a promising cancer treatment approach. However, the lack of imaging tools to assess immune checkpoint expression has been a major barrier to predicting and monitoring response to a clinical checkpoint blockade.


Comparison of (A) Cu-64-DOTA-HACPD1, (B) Cu-64-NOTA-HAC-PD1, and (C) Cu-64-NOTA-HACA-PD1 ImmunoPET images acquired at 1h p.i. (~1.85 MBq/10 μg/200 μl) of NSG mice bearing dual subcutaneous tumors in shoulders (right = hPD-L1+; left = hPD-L1-). Panels left to right show representative coronal and axial cross sections of CT, PET, and merged PET/CT images with maximum intensity projection (MIP). White dashed line, coronal image, demarcation of axial cross-section; White dashed line, axial image, tumor boundary. SG, salivary gland; T+, hPD-L1 positive tumor; T-, hPD-L1 negative tumor; L, lung; Li, liver; K, kidney; B, bladder; H, heart. Scale bars represent 1 percent (blue) - 6 percent (red) ID/g. Tumor uptake was quantified using ROI analysis (right panel) without partial volume correction. Error bars represent SD. ns, not significant; *p<0.05, **p<0.01, ***p<0.001, student's T test.

Credit: Sam Gambhir, MD, PhD, Stanford University

"Because immunotherapies for cancer are expanding, methods to optimize them for an individual patient through molecular imaging are needed," explains Sam Gambhir, MD, PhD, at Stanford University. "Using animal models, this study shows the development of several new engineered PET tracers that can help image the immune system in action and be used to monitor checkpoint inhibitor therapy."

The study assessed practical immunoPET radiotracer design modifications and their effects on human PD-L1 immune checkpoint imaging. The researchers sought to optimize engineering design parameters including chelate, glycosylation, and radiometal to develop a non-invasive molecular imaging tool for eventual monitoring of clinical checkpoint blockade.

Gambhir points out, "This research will ultimately allow for translation to human imaging of the tracer that worked best in animal models. An effective immunoPET tracer will help patients receiving checkpoint inhibitor immunotherapy get optimal treatment and have the best chance for fighting their cancer."

Molecular imaging is playing an increasingly integral role in immunotherapy and personalized medicine. Looking ahead, Gambhir envisions "a lot more use of PET/CT or PET/MR imaging for patients undergoing immunotherapy." He adds, "This and related research will also help us develop other imaging approaches for understanding the immune system in action."

###

The authors of "Practical ImmunoPET radiotracer design considerations for human immune checkpoint imaging" include Aaron T. Mayer, Arutselvan Natarajan, Sydney R. Gordon, Roy L. Maute, Melissa N. McCracken, Aaron M. Ring, Irving L. Weissman and Sanjiv S. Gambhir, Stanford University, Stanford, California.

Support for this study was provided by Kenneth Lau, Frezghi Habte, the Canary Foundation and the Ben and Catherine Ivy Foundation. This material is based upon work supported by a National Science Foundation Graduate Research Fellowship Grant (DGE-114747) and a NIH TBi2 Training Grant (2T32EB009653-06). MicroPET/CT imaging and Gamma Counter measurements were performed in the SCi3 Stanford Small Animal Imaging Service Center.

Please visit the SNMMI Media Center to view the PDF of the study, including images, and more information about molecular imaging and personalized medicine. To schedule an interview with the researchers, please contact Laurie Callahan at (703) 652-6773 or lcallahan@snmmi.org. Current and past issues of The Journal of Nuclear Medicine can be found online at http://jnm.snmjournals.org.

About the Society of Nuclear Medicine and Molecular Imaging

The Society of Nuclear Medicine and Molecular Imaging (SNMMI) is an international scientific and medical organization dedicated to raising public awareness about nuclear medicine and molecular imaging, a vital element of today's medical practice that adds an additional dimension to diagnosis, changing the way common and devastating diseases are understood and treated and helping provide patients with the best health care possible.

SNMMI's more than 17,000 members set the standard for molecular imaging and nuclear medicine practice by creating guidelines, sharing information through journals and meetings and leading advocacy on key issues that affect molecular imaging and therapy research and practice. For more information, visit http://www.snmmi.org.

Media Contact

Laurie Callahan
lcallahan@snmmi.org

 @SNM_MI

http://www.snm.org 

Laurie Callahan | EurekAlert!

Further reports about: CT imaging Nuclear Medicine PET PET radiotracer immune system immunotherapy

More articles from Medical Engineering:

nachricht A first look at interstitial fluid flow in the brain
05.07.2018 | American Institute of Physics

nachricht A sentinel to watch over ocular pressure
04.07.2018 | Fraunhofer Institute for Microelectronic Circuits and Systems

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Behavior-influencing policies are critical for mass market success of low carbon vehicles

17.07.2018 | Power and Electrical Engineering

Plant mothers talk to their embryos via the hormone auxin

17.07.2018 | Life Sciences

Subaru Telescope helps pinpoint origin of ultra-high energy neutrino

16.07.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>