MRI guided focused ultrasound surgery for the treatment of breast cancer

HIFU is an effective tool to generate precise localized tissue heating and subsequent tissue necroses deep in the body. Especially in combination with MRI target definition, detection of the heated area and the detection of morphological tissue changes are possible. After previous animal trials we show in the present study the transfer of this method to the clinical application. We have treated human breast cancer with HIFU under MRI guidance. For this purpose, a clinical treatment unit was developed and built up. A prospective clinical phase I study was started involving patients with biopsy proven invasive breast cancer. MRI-guided focused ultrasound therapy was applied before conventional breast surgery. On MR-images breast tumor delineation, tumor segmentation and HIFU treatment planning was possible. During ultrasound therapy, detection of the thermal focus and comparison with the planned focus position allowed a quasi on-line therapy control. Immediately after ultrasound therapy affected areas could be distinguished after intravenous application of MRI contrast agent as non-perfused area. Thus we could demonstrate that breast cancer in a human patient can be treated non-invasively in a single therapy session with HIFU under MRI guidance