Sept. 22, 2026 — Researchers from the Keck School of Medicine of USC are developing a new “plug-and-play” platform that could simplify and speed up the creation of new radiotracers, compounds used in positron emission tomography (PET) scans to visualize diseases such as cancer inside the body and track their progression.
The project, supported by a four-year, $2.6 million grant from the National Institute of Biomedical Imaging and Bioengineering, part of the National Institutes of Health, aims to expand the uses of PET imaging, potentially improving patient care while making the technology more affordable and accessible.
A radiotracer combines two components: a tiny amount of radioactive material and a biological molecule designed to seek out a specific target in the body, such as a protein found on cancer cells. Once injected, it is detected by a PET scan, which creates an image showing where the tracer has accumulated. Unlike imaging methods that primarily show the body’s anatomy, PET scans reveal biological activity happening inside the body. Because PET scanners are highly sensitive to the radioactive signal from a tracer, they can show where specific molecules or biological processes are occurring and how they change over time. This can help detect disease, locate tumors and monitor how well treatments are working.
Scientists can identify promising new biological markers faster than ever, but turning those discoveries into PET tracers remains a challenge. Attaching a radioactive substance to these molecules is a time-consuming and technically demanding process that requires specialized equipment and facilities.
To address this, the Keck School of Medicine team, led by Kai Chen, PhD, professor of research radiology, radiation oncology, and pharmacology and pharmaceutical sciences, is creating a “plug-and-play” platform that can be used to make a wide range of radiotracers. The platform combines a universal radioactive building block — which can be attached to different biological molecules—with a compact device, about the size of a coffee cup, that rapidly combines the two components to produce new radiotracers.
"This award recognizes the innovative work Dr. Chen and his team are conducting at the intersection of imaging science, chemistry and engineering — and the impact it could have on patients both here and around the world," said Joshua Hirsch, MD, chair of the Department of Radiology and the Stewart Dale Fordham, MD, Chair in Radiology at the Keck School of Medicine. "Their efforts have the potential to make advanced molecular imaging more accessible, accelerate the development of new PET tracers, and ultimately provide physicians with better tools to diagnose disease and guide personalized treatment.
A Miniaturized Platform
The platform brings together two advanced chemistry approaches: click chemistry and droplet radiochemistry. Click chemistry, a Nobel Prize-winning technique, allows scientists to quickly join molecules together, like buckling a seatbelt. Droplet radiochemistry carries out chemical reactions in extremely small droplets, using tiny amounts of material.
The innovation lies in combining these two approaches into a single platform that can produce radiotracers on a miniature scale. Working with collaborators at UCLA, Chen and his team are building a device that uses a tiny chip to combine the universal radioactive building block with different biological molecules.
“Because everything will be concentrated on a tiny chip, we hope to produce radiotracers quickly and efficiently with less reliance on traditional large-scale equipment and facilities,” Chen said.
Preliminary research suggests the approach can produce new radiotracers that could help detect and study several different types of cancer. One tracer is designed to target fibroblast activation protein, which is found at high levels in many tumors. The team is also testing tracers designed specifically to detect liver and prostate cancer.
“These findings are important because they show that click chemistry can rapidly generate tracers for multiple cancer biomarkers and that these tracers can be produced on a very small scale,” Chen said. “The funded project will further develop the platform and test it with a broader range of cancer-targeted tracers.” Beyond cancer research, the platform could be adapted to create radiotracers for other conditions, including neurological diseases.\
Expanding PET imaging
If the team is successful, the platform could automate and simplify radiotracer production, lowering the cost and reducing the resources required to create new tracers. That could make it possible to produce a wider range of customized tracers and potentially expand access to PET imaging.
More specialized tracers could give researchers and medical providers a closer look at what happens inside the body at a molecular level, including how biological features of a tumor change over time. This could allow providers to monitor a patient’s treatment response earlier and more precisely, potentially helping determine sooner whether a given therapy is working or a different approach is needed.
Chen and his team will spend the next one to two years optimizing the device and testing a range of radiotracers, comparing them with established tracers to determine how well they perform. They will then build and refine the final device, conduct quality control and preclinical testing, and begin working toward clinical applications.
This work is supported by the National Institute of Biomedical Imaging and Bioengineering, part of the National Institutes of Health [R01EB040161].
September 14, 2026 
