When breast cancer is detected, the first thing the doctor wants to know is whether it has spread to nearby lymph nodes. Unfortunately, the only way of determining this is to remove all potentially-affected nodes, and there are typically 30 of them in a woman’s armpit. With a view to minimizing surgical intervention, John V. Frangioni, M.D. PhD of Boston’s Beth Israel Deaconess Medical Center has developed a new imaging system that allows doctors to see exactly which lymph nodes a tumor drains into. Whether cancer cells have actually migrated to these nodes can be determined after the nodes have been removed. Known as Fluorescence-Assisted Resection and Exploration (FLARE), the system uses unique medical image fusion and visualization software developed by Siemens Corporate Research (SCR) that combines a visible light image of the area of interest with an image of the invisible infrared light reflected from a fluorescent substance. Injected into the area surrounding the tumor, the substance rapidly finds its way from the tumor to the nodes it drains into. The resulting hybrid image, which appears in real time on a color monitor, displays concentrations of brightness at the tumor and at its associated nodes, as well as a river of light beneath the skin indicating the fluid’s drainage path. And that’s just for starters. Optical systems could detect a spectrum of physiological processes indicative of cancer, such as changes in oxygen saturation and hemoglobin and water concentrations in tissues long before any anatomical or structural changes are visible to a surgeon’s eye. Such a tool could have far-reaching consequences . By providing feedback within hours regarding a tumor’s response to a new medication, in vivo optical imaging could inexpensively accelerate and personalize drug testing as well as patient treatment for shallow lesions as well as those that could be approached with future endoscopic devices. With this in mind, SCR researchers are working with the Beckman Laser Institute at the University of California in Irvine, to develop a novel software imaging platform for a hand-held laser and broadband diffuse optical spectroscopy probe that would work in much the same way as does an ultrasound transducer — but with light instead of sound. The device could be applied directly to the surface of the breast, where it will emit light at a range of wavelengths, enabling quantification of many physiological properties.