Ablation of Prostate Cancer by Thermal Rods

A new technique for using heat to ablate prostate cancer suggests it may be used alone as an alternative treatment option or at a lower temperature in combination with radiation.

The technique involves the percutaneous placement of small magnetic alloy rods into the prostate gland. The rods are biocompatible implants, made of cobalt and palladium, which can be permanent. The patient with the implanted rods is then placed in an extracorporeal alternating magnetic field. As the rods resist the current, they heat but only to a temperature limit that was set during their manufacture.

In a study of the technique, researchers examined the effects of the rods placed within I cm of each other at various temperatures, finding that 70o C resulted in necrosis of cancerous prostate tissue. The treatment was well tolerated and could probably be performed in an outpatient setting, say the researchers. Since rods are permanently implanted, patients could be easily retreated when serum prostate-specific antigen (PSA) levels increase. The researchers also believe that treatment at hyperthermia temperatures in combination with radiation would be useful, since studies have shown heat enhances the effects of radiation.

The research team was headed by Robert D. Tucker, M.D., University of Iowa College of Medicine (Iowa City, IA, USA), whose earlier paper on the new technique was published in the August 2000 issue of the Journal of Endourology.