Electromagnetic field focusing system in the treatment of brain tumors.

The electromagnetic field focusing (EFF) probe, which is based on the principle of eddy current convergence, produces intense pinpoint heat at its point of contact with tissue. This allows cutting and vaporization of tissue and coagulation of vessels. The present experiments were conducted to study heat distribution to the surrounding tissue in brain and phantom and the effect on the brain of vaporization of intracerebral tumors in 19 rabbits. The follow-up period was as long as 47 days. The heating pattern showed a rise of temperature up to 250 degrees C at the probe tip, with minimal or no temperature increase at 2 mm and beyond. Minimal or no change was noted in the surrounding brain after tumor vaporization, indicating that this system would be safe in the vaporization of brain tumors in clinical neurosurgery.