Feasibility and accuracy of 3D printed patient-specific skull contoured brain biopsy guides.

Objective: Design 3D printed skull contoured brain biopsy guides (3D-SCGs) from computed tomography (CT) or T1-weighted magnetic resonance imaging (T1W MRI).
Study Design: Feasibility study.
Sample Population: Five beagle dog cadavers and two client-owned dogs with brain tumors.
Methods: Helical CT and T1W MRI were performed on cadavers. Planned target point was the head of the caudate nucleus. Three-dimensional-SCGs were created from CT and MRI using commercially available open-source software. Using 3D-SCGs, biopsy needles were placed into the caudate nucleus in cadavers, and CT was performed to assess needle placement accuracy, followed by histopathology. Three-dimensional-SCGs were then created and used to perform in vivo brain tumor biopsies.
Results: No statistical difference was found between the planned target point and needle placement. Median needle placement error for all planned target points was 2.7 mm (range: 0.86-4.5 mm). No difference in accuracy was detected between MRI and CT-designed 3D-SCGs. Median needle placement error for the CT was 2.8 mm (range: 0.86-4.5 mm), and 2.2 mm (range: 1.7-2.7 mm) for MRI. Biopsy needles were successfully placed into the target in the two dogs with brain tumors and biopsy was successfully acquired in one dog.
Conclusion: Three-dimensional-SCGs designed from CT or T1W MRI allowed needle placement within 4.5 mm of the intended target in all procedures, resulting in successful biopsy in one of two live dogs.
Clinical Significance: This feasibility study justifies further evaluation of 3D-SCGs as alternatives in facilities that do not have access to stereotactic brain biopsy.
(© 2021 The Authors. Veterinary Surgery published by Wiley Periodicals LLC on behalf of American College of Veterinary Surgeons.)