Novel PET Tracer Offers Same-Day Imaging for Aggressive Breast and Bladder Cancers

A newly developed PET tracer can visualize a key cancer-related protein within just four hours, offering a same-day imaging option for patients with triple-negative breast cancer (TNBC) and urothelial bladder carcinoma (UBC). The research, published in the September issue of The Journal of Nuclear Medicine, highlights a tool that could speed up treatment decisions and help patients avoid ineffective therapies.

TNBC, an aggressive subtype, accounts for nearly one-quarter of new breast cancer cases. UBC is the most common urinary tract cancer, representing 90 percent of bladder malignancies. Many patients are diagnosed at advanced stages, making early detection and reliable monitoring critical.

Both TNBC and UBC frequently overexpress nectin-4, a protein that is also a target for emerging therapies. “We sought to develop a PET tracer that could rapidly and clearly visualize nectin-4 expression,” said Weibo Cai, PhD, professor of radiology and medical physics at the University of Wisconsin–Madison. “This could help clinicians identify patients most likely to benefit from targeted treatments and track their responses in real time.”

Researchers compared two tracers: one linked to a full antibody (⁶⁴Cu-NOTA-EV) and another linked to an antibody fragment (⁶⁴Cu-NOTA-EV-F(ab′)₂). In preclinical models, the fragment-based tracer accumulated in nectin-4–positive tumors within four hours and showed stronger tumor-to-background contrast. It also cleared from the body faster, reducing radiation exposure.

“This study demonstrates that ⁶⁴Cu-NOTA-EV-F(ab′)₂ enables rapid, specific, and sustained tumor imaging,” said Lei Kang, MD, PhD, professor of nuclear medicine at Peking University First Hospital. “In the future, this approach could expand to other cancers and imaging targets, making PET imaging faster, safer, and more patient-friendly.”