Creating a drill trajectory

[lassoan (Andras Lasso)]

I would recommend this workflow:

Combine patient and CAD models in 3D Slicer using union/intersection/difference operations

If you don’t want to use a 3D-printed guide then you can set up optical or electromagnetic tracking as described in SlicerIGT tutorials.

I would also recommend to consider using ultrasound for real-time imaging and guidance. See for example this demo:

Real-time 3D ultrasound reconstruction using 3D Slicer + SlicerIGT