The OHSU scientists have shown that an iron oxide nanoparticle as small as a virus can outline not only brain tumors under magnetic resonance imaging, but also other lesions in the brain that may otherwise have gone unnoticed, according to a study published in the journal Neuropathology and Applied Neurobiology.

So named because of its billionth-of-a-meter proportions, the iron oxide nanoparticle, ferumoxtran-10, can be viewed as a contrast agent under MR for more than 24 hours, sometimes as long as five days, said the study's lead author, Edward Neuwelt, M.D., professor of neurology and neurological surgery, OHSU School of Medicine, and the Portland VA Medical Center.

In a parallel study by Neuwelt and colleagues, to be presented in June to the American Society of Neuroradiology, ferumoxtran-10 also was found to provide a "stable imaging marker" during surgery to remove brain tumors, and it remains in the brain long enough for post-operative MR, even after surgical manipulation.

The studies' findings have the potential to assist image-guided brain surgery and improve diagnosis of lesions caused by multiple sclerosis, stroke and other neurological disorders, in addition to residual tumors.

"This is one of the first biologically specific nanoparticles to be used in clinical trials," said Neuwelt, director of OHSU's Blood-Brain Barrier Program, which studies ways of outwitting the brain's natural defense to treat people with brain tumors. "This is the first time it's been applied to look at inflammatory lesions in the brain, not just tumors. They're very interesting particles and they're safe."

Study co-author Gary Nesbit, M.D., associate professor of diagnostic radiology and neurological surger
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Contact: Jonathan Modie
modiej@ohsu.edu
503-494-8231
Oregon Health & Science University
26-May-2004