Design and testing of an interstitial therapeutic ultrasound applicator for the thermal ablation of cerebral tumors.

Abstract

Conventional treatments for cerebral tumors involve surgical resection of the lesion in combination with chemotherapy or radiotherapy. In this work, an alternative, minimally invasive approach is presented for thermally ablating cerebral tumors using an interstitial ultrasound transducer. Initial testing and characterization of a prototype device based on a mono‐element design is presented. Heating experiments are performed in tissue phantoms and in ex vivo bovine and sheep brain. Real‐time temperature monitoring and lesion characterization are performed using magnetic resonance imaging (MRI). Furthermore, obtained temperature rise and lesion volume registered on MRI are compared with numerical modeling. The results demonstrate that the prototype interstitial probes have good MRI compatibility and are capable of ablating a volume of tissue of up to several centimeters in diameter in several minutes under real‐time MRI guidance. Furthermore, there is a possibility to precisely tailor the lesion volume to the treatment zone using a rotational approach. [Work supported by the ASA Hunt Fellowship and CarThéra SAS.]