The treatment of early stage, localized breast cancer has evolved over several decades from highly invasive techniques to minimally invasive, breast-conserving therapies. Our breast-specific magnetic resonance-guided focused ultrasound system non-invasively delivers focused energy deep inside the body under high-resolution image guidance. The technical advances we have made poise MRgFUS as a nearly ready non-invasive ablation treatment for localized breast disease. We have developed a rapid, treatment planning package to predict ultrasound beam placement and assess potential beam aberration, a hybrid MR thermometry method to monitor temperature in both fat and aqueous based tissues and validated a novel MRI-registered whole mount histology technique that compares MRI metrics to histopathological analysis. This R37 2-year extension proposal will continue this work between experienced academic investigators at the University of Utah and industry investigators at Image Guided Therapy. This extension will finish and extend this important work, integrating each component into ThermoGuideTM, a clinic-ready focused ultrasound software control environment. Specifically, we will: 1) Use the rapid treatment planning technique to evaluate the necessity for phase aberration correction techniques in breast MRgFUS, 2) validate the accuracy and precision of our hybrid, breast-focused volumetric MR thermometry method, 3) apply our novel MRI-registered whole mount histology technique that compares MRI metrics to histopathological analysis to immunohistochemistry data and 4) evaluate the entire protocol in a feasibility treat-and-resect clinical trial targeting unifocal invasive breast cancer tumors. This R37 extension application will complete the validation and translation of the breast MRgFUS System in this proposal, providing an exciting new image-guided non-invasive treatment option for breast cancer patients.

The validation of breast-specific treatment planning, monitoring and assessment techniques will accelerate translation of a magnetic resonance-guided focused ultrasound system towards the efficient, non-invasive treatment of localized breast cancer. Incorporation of validated techniques in a clinic-ready planning, monitoring and assessment software package will enable a feasibility clinical trial to verify this non-invasive therapy can achieve efficacy within acceptable safety limits.