Robotic system for biopsy and therapy of breast lesions in a high-field whole-body magnetic resonance tomography unit

RATIONALE AND OBJECTIVES. With magnetic resonance mammography, significant progress has been achieved in the diagnosis of small breast cancers, Howeve r, biopsy and therapy of suspicious lesions must take place at a later time . Diagnosis and simultaneous biopsy and therapy in one single examination w ould considerably reduce costs, strain on the patient, and side effects. METHODS. ROBITOM (Robotic system for biopsy and interventional therapy of m ammary lesions) is used to approach a lesion found in the breast in an imag e-controlled manner under a high magnetic field (eg, 1.5 T), The robotic sy stem works in the direct vicinity of the isocenter of a magnet and consists of a trocar, coaxial sleeve, biopsy needle, laser applicator, and a contro l and driving unit. It contains a rack, a driving unit along the three coax es of space, and a gripping unit for instruments or biopsy sample removal. The system has six degrees of freedom. RESULTS. In vitro experiments in pig liver including eight targets (vitamin E capsules, 4 mm in diameter) were performed. All eight capsules were hit precisely by the robotic biopsy system. The procedure was performed directl y in the isocenter of a 1.5-T whole-body scanner. CONCLUSIONS. The system allows the coordinates of a lesion in the breast to be approached in a high magnetic field without shifting the patient, A com bination of imaging with biopsy and subsequent therapy leg, laser therapy o r cryotherapy) seems to be feasible in the future.