One of the major downsides of current cancer diagnosis technologies is that a tumor can often grow to a damaging size by the time imaging methods detect it. Catching a cancer when it metastasizes can also be tricky as doctors generally won't know the disease has spread until it's too late.

This new detection method involves injecting a subject with nanoparticles that emit short-wave infrared light. These nanoparticles travel through the bloodstream and are designed to stick to specific cancer cells. In early mouse experiments the particles accurately identified and tracked breast cancer cells as they spread to several other locations in the animal's body.

"We've always had this dream that we can track the progression of cancer in real time, and that's what we've done here," says corresponding author of the study Prabhas V. Moghe. "We've tracked the disease in its very incipient stages."