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. However, biopsy and therapy of suspicious lesions must take place at a later time. Diagnosis and simultaneous biopsy and therapy in one single examination would considerably reduce costs, strain on the patient, and side effects.

METHODS

ROBITOM (Robotic system for biopsy and interventional therapy of mammary lesions) is used to approach a lesion found in the breast in an image-controlled manner under a high magnetic field (eg, 1.5 T). The robotic system works in the direct vicinity of the isocenter of a magnet and consists of a trocar, coaxial sleeve, biopsy needle, laser applicator, and a control and driving unit. It contains a rack, a driving unit along the three coaxes 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 directly 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 combination of imaging with biopsy and subsequent therapy (eg, laser therapy or cryotherapy) seems to be feasible in the future.