Interventional MRI of the breast: minimally invasive therapy.

In recent years a variety of minimally invasive therapies have been applied to the treatment of breast lesions. These therapies include thermal treatments (interstitial laser coagulation, focused ultrasound, radiofrequency and cryotherapy), percutaneous excision, and interstitial radiotherapy. Magnetic resonance has been used in these treatments to visualize lesions before, during and after therapy and to guide interventions. "Temperature-sensitive" sequences have shown changes with thermal ablation which broadly correlate with areas of tumour necrosis. Consequently, MR has the potential to monitor treatment at the time of therapy. To date, experience in the treatment of breast cancer has been restricted to small studies. Large controlled studies are required to validate the efficacy and safety of these therapies in malignant disease.