3D-Printed Cutting Guide in Oncological Pelvic Surgery: A Case Report and Proof of Concept Validation of Cutting Guide Accuracy.

Introduction: In recent years, numerous hospitals have established in-house three-dimensional (3D) printing centers, enabling health-care facilities to leverage the transformative capabilities of additive manufacturing technology on their premises. With this emerging opportunity arises a necessity to undertake a thorough assessment of the manufactured tools employed in clinical practice. The objectives of this article are to describe the pathway of in-house printing and evaluate the accuracy of 3D-printed specific instruments. Case Report: A case is reported along with the workflow for creating a patient model and cutting guide. The patient is a 76-year-old Caucasian woman with bone metastasis from a known renal cancer located in the pelvis. The model was used preoperatively, while the guide was used during surgery. Following this, the guide underwent computed tomography (CT) scanning, and a 3D digital model was reconstructed. Two dimensions, labeled A and B, were established. We compared pre-operative measurements, respectively, with measurements from the printed physical guide and from the rescanned post-operative digital model. Finally, A and B were measured on the bone defect on the patient's post-operative CT. Variation in axis A value between the mean of the first two groups was 0.5 mm and in axis B was 0.7 mm. On the printed physical guide, the mean of axis A was 73.5 mm, and the mean of axis B was 71.8 mm. Variation in A value between the mean of this group and the pre-operative was 1.7 mm and in B value was 0.5 mm. Conclusion: The workflow used at our hospital was described with an example of how to evaluate the accuracy of in-house 3D printing. Results showed high accuracy of the printing method, a reliable correlation between desired and actual outcomes, and a short lead time.