BACKGROUND: A new monitoring system called ValiMed flashes an ultraviolet light on tiny samples of chemotherapy drugs to make sure that the right combination and dose of chemotherapy is being administered to each patient. It's the same principle used to detect bombs.
CHEMICAL FINGERPRINTS: The ValiMed system is based on the fact that most drugs have a unique chemical "fingerprint" that can be detected when the drugs are exposed to ultraviolet light. It is a unique pattern that tells scientists when a particular molecule is present in a sample. Each chemical element emits or absorbs radiation at specific wavelengths. Sodium, for example, emits mostly orange light, while the oxygen used in neon lights emits green light.
WHAT LIGHT CAN REVEAL: Anything that produces light or radiates energy reveals information about itself. Spectroscopy is a technique used by physicists and astronomers to study the makeup of an object or substance based on the kind of light it emits. For instance, with spectroscopy, astronomers can determine what stars are made of, similar to chemical fingerprinting. By passing light from a star through an instrument called a spectrograph, the light "spreads out" into a colorful spectrum, much like passing white light through a prism. By studying how the spectrum becomes brighter or darker at each wavelength, scientists can tell what chemical elements are in the star. They can also determine its temperature, density, or how fast it might be spinning.
ABOUT CHEMOTHERAPY: Chemotherapy is a treatment for cancer, in which certain drugs (poisonous to cancer cells) are injected into the blood to kill cancer cells or to stop them from spreading. They can travel around the body and attack cancer cells wherever they find them, so chemotherapy is used when cancers have spread beyond one region of the body.