Magnetic
metal particles are known to induce heat energy under an alternating magnetic field (AMF). We developed a local
tumor-heating device incorporating an MgFe(2)O(4) needle for the purpose of mild ablation for
cancer treatment. A needle made from sintered MgFe(2)O(4) particles was embedded in the hepatic or
breast tumors.
Tumors were then heated by the energy dissipated from the needle exposed to an AMF. We sequentially evaluated histological changes, cellular activity of
tumors, and the extent of thermal effect using
nicotinamide adenine dinucleotide (
NADH) diaphorase and terminal deoxynucleotidyl tranferase-mediated
digoxigenin-DUTP nick-end labeling (TUNEL) staining. The mean temperature of the
tumor tissue during heating was about 60 degrees C. Nuclei of the
tumor cells became hyper-
chromatin immediately after heating. The injured area spread progressively until 3 days after heating; when the area was surrounded by fibroblasts (meaning is not clear).
Tumors disappeared
after treatment without complications. This is the first time that the complete death of
tumor cells has been realized by raising the
tumor temperature above 60 degrees C using the heat generated by magnetic
metal particles exposed to AMF. This device may be useful in the future for local hyperthemic treatment of human
cancers.