Researchers at Washington University in St. Louis have developed a dual imaging approach that does something previously impossible: watch a tumor and an inflamed heart at the same time during cancer treatment. Using a specialized PET scan targeted at the CCR2 protein, Jaume Otaegui and his team can now visualize both the cancer's response to therapy and dangerous inflammatory changes in the cardiovascular system—two competing risks that have long forced difficult clinical trade-offs.
The challenge is real. Immune checkpoint inhibitor drugs, or ICIs, have transformed cancer survival rates by unleashing the body's own immune system to attack tumors. But in some patients, these same treatments trigger serious heart and blood vessel complications that can force doctors to stop cancer therapy altogether, leaving tumors free to progress. Until now, clinicians had no molecular imaging tool to detect these cardiovascular dangers before they became life-threatening—no way to see the inflammation building in a patient's arteries while monitoring the tumor.
The Washington University team tested their approach in mice with both atherosclerosis and oral carcinoma, mimicking the real-world cardio-oncology challenge. Using a radiotracer called 64Cu-DOTA-ECL1i that binds specifically to CCR2—a protein present in both inflamed plaques and tumors—they performed PET imaging to track both disease sites simultaneously. The first group received standard ICI therapy twice a week. As expected, the cancer slowed but the cardiac inflammation spiked, with CCR2 signals in the heart increasing significantly. This is the invisible danger clinicians currently face.
But the second group revealed something promising. When researchers added itacitinib, a Janus kinase 1 inhibitor, to the ICI regimen during the final two weeks of treatment, the results shifted dramatically. The combination therapy not only achieved better tumor control than ICI alone, but also reduced the CCR2 signal in the heart and decreased inflammatory cells infiltrating the aorta. For the first time, researchers had demonstrated a way to improve cancer outcomes while protecting the heart.
The implications extend far beyond mice. The 64Cu-DOTA-ECL1i radiotracer is already in clinical trials across multiple disease indications, and ICI therapies have FDA approval for several stages of head and neck cancer. This means the imaging component could reach patients relatively soon, offering clinicians an early warning system for cardiovascular complications. Otaegui envisions a future where doctors can continuously monitor a patient's cardiac inflammation during cancer treatment and adjust therapy before a heart attack or myocarditis strikes.
"CCR2 PET imaging could potentially allow clinicians to detect harmful cardiovascular changes that occur during cancer treatment before they result in heart attack, myocarditis, or other serious complications," Otaegui explained, pointing toward what he calls more personalized and safer immunotherapy. The work, presented at the Society of Nuclear Medicine and Molecular Imaging 2026 Annual Meeting, represents a shift toward treatment strategies that don't force doctors to choose between fighting cancer and protecting the heart.
Still, larger studies are needed before the combination therapy enters clinical practice. But for patients already balancing the hope of immunotherapy against the fear of cardiac complications, this dual-imaging approach offers something increasingly rare in medicine: the possibility of having both.