A new device and method for stereotactic CT-guided brain biopsy in dogs.

Objective: The objectives of this study were to design and construct a device for CT- guided stereotactic biopsy in the canine brain. Study design: The new device is composed basically of two main parts, a hard frame to fix the head of the animal and a guiding system to direct the instruments in a predefined direction. The frame has a scale system composed of two scales that are used to define the three spatial coordinates any intracranial target point. To operate the whole device a mathematical model was design, this model defines the position of the guiding system parts. Methods: To test the accuracy of the new device four targets were defined inside the skull of a dead specimen, a small amount of contrast material was injected and the coordinates of the injection center were compared with the previously defined target coordinates. Results: The mean geometrical error for all four targets was 1.28 0.124 mm. Conclusion: The new device allows performing the biopsy procedure, fast and precisely. The mathematically definition of the approach angle to the target improves the safety of the procedure. Clinical Relevance: The new device can be used not only for brain biopsy, but also to deliver biological or chemical therapeutic agents intralesionally.