ABSTRACT
The application of acoustic energy for tumor treatment is not a new idea. More than a half
century ago, focused ultrasound surgery (FUS) was already considered viable as a
“surgical” technique for treating deeply embedded soft-tissue tumors noninvasively.
Despite this early recognition of its potential, FUS has not been widely accepted as a real
alternative to invasive surgery. The reason is not the limitation of FUS technology but the
inadequacy of image guidance and the control of energy deposition. We believe strongly
that the integration of FUS with magnetic resonance imaging (MRI) represents a major
step toward a noninvasive image-guided therapy substitute that can replace most of the
existing tumor surgery methods. MRI-guided focused ultrasound (MRIgFUS) surgery
that has been developed during the last decade (1,2) provides accurate targeting of
focused sound waves that can be directed to destroy tumor tissue within MRI-detected
tumor margins. MRI not only provides tumor localization with high sensitivity but also
monitors temperature distribution in “real time,” effectively generating “temperature
maps” of the targeted surgical field during treatment. In turn, this allows the FUS delivery
of thermal energy at safe, therapeutically effective doses “without” damaging collateral
normal tissue. The integration of MRI and FUS creates an image-guided therapy delivery
system with which real-time, image-controlled, noninvasive soft-tissue coagulation is
feasible, and from which a wide range of clinical applications may ultimately develop.
THE DEVELOPMENT OF THE TECHNOLOGY
