Challenge The treatment of loco-regional breast cancer has evolved from radical mastectomy to targeted local breast conserving therapy. Using focused ultrasound surgery, we wanted to design a device that would non-surgically treat tumors in the breast. Many breast treatment systems have been developed, but in most of those studies, the breast was compressed and acoustic energy was shot vertically into the breast from the bottom. This design is uncomfortable and causes a far-field reflection and safety issue due to the presence of the ribs and lungs in the far field of the ultrasound.
Solution In this work, we designed a laterally mounted phased-array breast-specific MRgHIFU devicethat integrates several features intended to improve the treatment efficacy and safety of MRgHIFU in the breast. The design allows treatment of a large volume of the breast, increases signal-to-noise ratio (SNR) throughout the entire breast volume and provides adequate patient comfort for a MRgHIFU treatment. Multiple transducer designs were considered and tested. The system was designed to have electronic focal zone steering capabilities of approximately 1.5 cm in all directions in order to treat a 3-cm diameter spherical lesion without having to mechanically move the transducer. Using lesion size as the metric, this would allow the treatment of approximately two-thirds of lesions in a study that was comprised of
more than 24 000 breast cancer cases.
A Payne, R Merrill , E Minalga, U Vyas, J Bever, N Todd, R Hadley, E Dumont, L Neumayer, DA Christensen, R Roemer, DL Parker, “Design and characterization of a laterally mounted phased-array transducer breast-specific MRgHIFU device with integrated 11-channel receiver array.” Medical Physics, 39, 1552, 2012