C-arm cone beam CT guidance of sinus and skull base surgery: Quantitative surgical performance evaluation and development of a novel high-fidelity phantom

Surgical simulation has become a critical component of surgical practice and training in the era of high-precision imageguided surgery. While the ability to simulate surgery of the paranasal sinuses and skull base has been conventionally limited to 3D digital simulation or cadaveric dissection, we have developed novel methods employing rapid prototyping technology and 3D printing to create high-fidelity models from real patient images (CT or MR). Such advances allow creation of patient-specific models for preparation, simulation, and training before embarking on the actual surgery. A major challenge included the development of novel material formulations compatible with the rapid prototyping process while presenting anatomically realistic flexibility, cut-ability, drilling purchase, and density (CT number). Initial studies have yielded realistic models of the paranasal sinuses and skull base for simulation and training in image-guided surgery. The process of model development and material selection is reviewed along with the application of the phantoms in studies of high-precision surgery guided by C-arm cone-beam CT (CBCT). Surgical performance is quantitatively evaluated under CBCT guidance, with the high-fidelity phantoms providing an excellent test-bed for reproducible studies across a broad spectrum of challenging surgical tasks. Future work will broaden the atlas of models to include normal anatomical variations as well as a broad spectrum of benign and malignant disease. The role of high-fidelity models produced by rapid prototyping is discussed in the context of patient-specific case simulation, novel technology development (specifically CBCT guidance), and training of future generations of sinus and skull base surgeons.