Thermal ablation of a confluent lesion in the porcine kidney with magnetic resonance guided high intensity focused ultrasound

Since approximately 1.6 percent of men and women will be diagnosed with kidney and renal pelvis cancer during their lifetime, there is a growing interest in non-invasive kidney sparing therapy for renal cancer. As a consequence, several patient studies investigated the feasibility of high intensity focused ultrasound (HIFU) for the thermal ablation of renal masses. The majority of these studies used either a hand-held extracorporeal ultrasound transducer with ultrasound imaging for guidance or a laparoscopic approach. Drawbacks of these techniques are the lack of respiratory motion compensation, no means to observe the energy deposition in real time, the complexity of the probe positioning, and the risks of bleeding and tumor spillage. Alternatively, recent preclinical studies have demonstrated the feasibility of magnetic resonance guided high intensity focused ultrasound (MR-HIFU) interventions on the kidney with respect to motion compensated real-time thermometry and acoustic energy delivery. Here, we extend this prior work to investigate in an animal study if MR-HIFU can deliver a reliable confluent volumetric lesion in the renal cortex in a clinically relevant time-frame.