[Magnetic resonance-guided therapy with focused ultrasound. Non-invasive surgery of breast carcinoma?].

Magnetic resonance guided focused ultrasound surgery (MRgFUS) has the potential to become an important therapy modality in the adjuvant, neoadjuvant or palliative cancer treatment. All ultrasound accessible regions are possible target areas, especially breast tumors. Ultrasound propagation is well predictable. The ultrasound energy can be focused to a defined spot through the intact skin, and temperatures of 60 degrees C to 85 degrees C can be induced locally for a few seconds that instantaneously necrose biological tissues, while sparing surrounding healthy tissue. In addition, MRI is sensitive to temperature allowing for online monitoring of the temperature focus. In this work we demonstrate our Heidelberg experiments from basic research and animal studies towards the clinical realization of MRgFUS in breast cancer patients. The most important of these experiments involved sheep as an appropriate model for the human breast. A new therapy setup is designated to treat human breast patients in a clinical 1.5 T MRI scanner. While the therapies have been successful so far without any side effects, the future clinical role of noninvasive MRgFUS has to be defined by clinical studies.