Researchers at Duke University have begun testing encapsulated chemotherapy drugs using a thermal system that provides precision heat therapy in women whose breast cancers have spread to their chest wall. BSD Medical Corp., Salt Lake City, (bsdmc.com) manufactures equipment that provides the heat as focused radio frequency and microwave energy. The treatment uses a chemotherapy drug packed into tiny heat-sensitive capsules. When the capsules are delivered by blood flow to a tumor, it is heated, causing the capsule to release the chemotherapy without subjecting the rest of the body to the drug's toxicity. Duke University's Mark Dewhirst says heat boosts the killing power of radiation and chemotherapy by a factor of 10.

What's more, heat therapy makes tumor blood vessels porous so capsules can pass more easily into the tumor. That lets the method deliver 30 times more drug than would normally reach the tumor. In addition, heat increases a tumor's oxygen levels, critical to the proper functioning of many chemotherapy agents.