Targeted microwave hyperthermia monitored with ultrasound thermography

Traditional microwave hyperthermia utilizes antenna placement and endogenous absorption of energy to increase temperature in tumors. Unfortunately, there is too little contrast in electromagnetic absorption between tumors and surrounding normal tissues. We suggest that using biocompatible targeted iron-oxide nanoparticles can increase energy absorption in tumors. A preliminary study using magnetite nanoparticles injected into ex-vivo porcine muscle tissue shows promise with a 25°C increase in only 50 seconds in the inoculated region; approximately 17°C increase over the surrounding tissue. Temperature maps were acquired by monitoring the temperature-induced apparent displacements of ultrasound speckle in the tissue. To illustrate the effectiveness of this technique, thermal dose was assessed using an Arrhenius cell death model. Future studies will include an in-vivo experiment with a tumor-baring organ.