From Chicago, at a meeting of the American Society of Clinical Oncology
A new technique utilizing microscopic, fluorine-packed particles can vividly show small, cancerous growths that don’t appear in standard medical imaging. Finding cancer early can improve a patient’s chances for survival, but small tumors can be difficult to see with scanning techniques such as magnetic resonance imaging (MRI).
For the new tagging procedure, scientists first wrap droplets of fluorine-containing liquids in a layer of fat molecules. These nanoparticles, as the researchers call them, are about 200 nanometers across, roughly one-thirtieth the size of a red blood cell. The particles include surface molecules engineered to bind only with cancer cells. Injected into cancer-bearing mice, the particles selectively cluster onto tumors.
In an MRI machine, fluorine emits a strong signal with a characteristic frequency. Tuning the MRI equipment to that frequency creates a clear image of the tumor without showing surrounding tissues.
“So now we’re not imaging the protons or water in your body [as MRI customarily does], we’re imaging the fluorine that’s in this nanoparticle. And that’s important because it’s a unique signature with no background,” says Samuel A. Wickline of the team that created the technique at the Siteman Center of Cancer Nanotechnology Excellence in St. Louis. Scientists had used fluorine-based MRI to track drugs in the body, but no one had ever used fluorine and targeted particles to image cancer, he adds.