FRIDAY, March 9, 2007 (HealthDay News) -- Microscopic, heated "nanoprobes" slowed the growth of tumors in laboratory mice with aggressive human breast cancer without damaging surrounding healthy tissue, a new U.S. study reports.
The use of heat as a potential treatment for cancer is not a new concept, but its use has been limited due to the challenge of confining the heat to the tumor and calculating an effective heat dose.
A team from the University of California, Davis, in collaboration with scientists from Triton BioSystems in Boston, injected magnetic nanoprobes into the bloodstreams of the mice. About 10,000 of these nanoprobes can fit on the end of a straight pin.
The nanoprobes traveled through the bloodstream and latched onto receptors on the surface of cancer cells. A few days later, the scientists applied an alternating magnetic field (AMF) to the area of the tumor, which caused the nanoprobes to generate heat.
The mice received a series of AMF bursts in a single 20-minute treatment. Dosing was calculated using an equation that included the concentration of bioprobes in the tumor, the heating rate of particles at different amplitudes, and the spacing of the AMF bursts.
The treatment slowed tumor growth in the mice and did not cause any toxicity, the study said.
"We have demonstrated that the system is feasible in laboratory mice. The next step will be clinical testing in patients," lead author Sally DeNardo, a professor of internal medicine and radiology at the university, said in a prepared statement.
The study is published in the March issue of the Journal of Nuclear Medicine.
The U.S. National Cancer Institute explains hyperthermia in cancer treatment.