CAOS in bone tumor surgery

Abstract

Wide local resection with an adequate margin is a crucial step in the management of patients with bone sarcoma. Inaccurate resection with an inadequate margin is associated with a high risk of local recurrence and poor patient survival. Orthopedic oncologist surgeons are often faced with the dilemma of how much normal tissue to preserve to retain good function without compromising an adequate margin. With the advent of medical imaging and computer technology, tumor surgeons are increasingly using computer-assisted surgery for bone tumor resection. Computer-assisted orthopedic surgery helps surgeons replicate their preoperative plans, and this improved accuracy may have clinical benefits. This chapter provides an overview of the techniques that have emerged in bone tumor surgery over the past decade, including (1) three-dimensional (3D) surgical planning, intraoperative navigation-assisted resection, and patient-specific instrumentation (PSI)-assisted bone tumor resection, (2) clinical indications and early results of these techniques, and (3) possible future developments. The workflow includes 3D surgical planning with fusion of preoperative computed tomography/magnetic resonance imaging results and the integration of digital data for computer-aided design tumor implants or allografts. Computer navigation and PSI are the tools needed to implement 3D surgical planning. The current indications for computer-assisted tumor surgery (CATS) in patients with bone tumors include the following: (1) pelvic and sacral tumors that are at anatomically complex locations with nearby vital structures; (2) technically demanding resections, such as joint-preserving operations or multiplanar tumor resections; and (3) resections that must accommodate a custom tumor implant or match an allograft for reconstruction. The early clinical results suggest that the technique is feasible and safe, and it improves surgical accuracy. Nevertheless, surgeons must be aware of the potential errors when using the technique. An all-in-one planning platform for all users and the integration of 3D printing technology into the CATS workflow are potential areas for future development. Larger studies with longer follow-up periods are essential to determine the real clinical efficacy of the technique.