Teamwork

The ability of heat to kill cancer cells is no new discovery. Scientists have known about the use of hyperthermia (elevated temperatures) in the treatment of cancer for over 80 years. Recently, however, researchers such as Dr. Evan B. Douple, a radiobiologist at the Norris Cotton Cancer Center in Hanover, have determined how much heat (108.5° F.), applied for how long (three hours), is necessary to kill 99.95 per cent of cancer cells in a laboratory culture.

The problem with using heat to kill cancer cells growing within the human body is how to warm the cancerous tissue to 108.5° F. without damaging the surrounding normal tissue. Although externally applied, non-invasive techniques would be the ideal for clinical treatments, the wide variety in size, shape, location, and type of tumors makes non-invasive techniques infeasible. An interdisciplinary team of researchers at Dartmouth, including engineers, physicians, and a physicist, has been working toward a solution, investigating an invasive technique for applying heat in the form of microwave energy.

John Strohbehn, associate dean and professor of engineering at Thayer School, is coordinating the team's engineering efforts from an office on the second floor of Nathan Smith Hall, which used to house the Dartmouth Medical School. "We have designed a microwave antenna that looks like a hypodermic needle," said Strohbehn. "One can insert the antenna into the center of a tumor through the hypodermic needle, and then withdraw the needle, leaving the antenna implanted. By hooking up the antenna to microwave power, the tumor can be heated from the inside. This restricts the heat to a localized area without affecting lots of normal tissue."

Dartmouth physics professor John Walsh is credited with the original idea for the design. The group also includes Dr. Peter Runstadler, adjunct professor of engineering and president of Creare Inc. (a Hanover-based consulting firm), Dr. David Roberts, a neurosurgeon at the Hitchcock Clinic, and several graduate students from Thayer School. Most recently, the hyperthermia team has been working to modify their techniques and equipment for the purpose of treating deep-seated brain tumors.

Strohbehn said that the Thayer School's involvement in biomedical engineering dates back to a 1971 decision to make biomedical engineering an area of academic concentration. Since that time, a close association has developed between Thayer, the Dartmouth Medical School, and Mary Hitchcock Hospital. "Because of their reasonably small size and proximity," Strohbehn said, "certain bureaucratic problems that could arise are minimal."