New Imaging Probe to Transform Brain Cancer Surgery

Glioblastoma is one of the most challenging brain cancers to treat surgically due to its diffuse nature and ability to invade healthy brain tissue through microscopic extensions that are invisible to the naked eye. These finger-like projections make complete removal nearly impossible without damaging critical brain areas. Even a small number of remaining cancer cells can lead to recurrence, requiring surgeons to balance maximal tumor removal with preservation of brain function. Currently, MRIs are the gold standard for imaging tumors; however, they’re expensive and time-consuming, especially when required during an operation. To improve surgical accuracy and patient outcomes, researchers have now developed a new imaging probe that can help surgeons better identify and remove aggressive tumors during surgery.

This new tool, called FA-ICG, was developed by researchers at the University of Missouri (Columbia, MO, USA) in collaboration with other institutions. In their study published in Nature Publishing Group Imaging, the research team sought to address the limitations of existing imaging tools used during brain tumor surgeries by introducing a probe that is more effective, safer, and easier to use in real-time surgical settings. FA-ICG combines a long-chain fatty acid (FA) with indocyanine green (ICG), a near-infrared dye already approved by the FDA for surgical imaging. Glioblastoma cells have an elevated uptake of fatty acids, and this trait is leveraged by FA-ICG to selectively accumulate in cancerous tissue. Once inside the tumor, the dye causes the cells to glow under near-infrared light, making them easier to distinguish from surrounding healthy brain tissue during surgery.

Current surgical guidance tools include microscopes, ultrasound, and fluorescent dyes, but these have notable limitations. The only approved dye for glioblastoma, 5-ALA, requires a darkened operating room, has weak tissue penetration, and can cause photosensitivity in patients post-surgery. In contrast, FA-ICG addresses these issues by offering a brighter signal, working under standard surgical lighting, and enabling real-time visualization without interrupting the surgical workflow. Its signal-to-background ratio is significantly higher than existing tools, enhancing tumor visibility and surgical precision.

In addition to improving visibility, FA-ICG has operational advantages. Its extended half-life offers greater scheduling flexibility, and it is easier to administer than current alternatives. Researchers are also investigating its potential in other applications, such as surgeries for cancers with high fatty acid metabolism and photodynamic therapy, where its light-activated properties may help destroy residual cancer cells. Clinical trials in Europe are planned to assess safety, tolerability, and comparative performance in glioblastoma surgeries. If successful, the probe could mark a major advancement in brain cancer surgery and potentially be adapted for use in treating other solid tumors.

“This fluorescent metabolically linked tool gives you real-time imaging,” said Michael Chicoine is a neurosurgeon at MU Health Care and chair of Mizzou’s School of Medicine’s Department of Neurosurgery. “We could merge techniques, using the probe during surgery and saving the MRI for a sort of final exam. It’s definitely an exciting advancement.”