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

Richard Shinn,Thomas Cecere,Clair Park,Kyrille Debose,John Rossmeisl,Fang‐Chi Hsu

doi:10.1111/vsu.13641

Abstract

ObjectiveDesign 3D printed skull contoured brain biopsy guides (3D‐SCGs) from computed tomography (CT) or T1‐weighted magnetic resonance imaging (T1W MRI).Study DesignFeasibility study.Sample PopulationFive beagle dog cadavers and two client‐owned dogs with brain tumors.MethodsHelical 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.ResultsNo 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.ConclusionThree‐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 SignificanceThis feasibility study justifies further evaluation of 3D‐SCGs as alternatives in facilities that do not have access to stereotactic brain biopsy.

Highlights

Intracranial neoplasia is a significant cause of morbidity and mortality in dogs, with a prevalence of 14.5 per 100 000 animals.[1]
We hypothesized that 3DSCGs could be designed based on magnetic resonance imaging (MRI) and computed tomography (CT), would be accurate for biopsy needle placement, and that CT-designed 3D printed skull contoured brain biopsy guides (3D-SCGs) would be more accurate than MRI-designed 3D-SCGs, as the bone detail provided by CT would facilitate a better fit of the 3D-SCG to the skull
Biopsy specimens were fixed in 10% neutral buffered formalin for a minimum of 24 h paraffin-embedded, and 5 μm sections were stained with hematoxylin and eosin (H&E) and murine monoclonal antibody against glial fibrillary acid protein

Summary

| INTRODUCTION

Intracranial neoplasia is a significant cause of morbidity and mortality in dogs, with a prevalence of 14.5 per 100 000 animals.[1]. Frame-based SBB has been investigated in dogs and utilized effectively with precision and diagnostic yields comparable with human studies.[7,8,9] several limitations, such as flexibility and patient discomfort, have been reported in people suggesting the need for different methodologies, including frameless techniques with robot-assisted or imageguided neuro-navigation.[6,10] The use of stereotactic devices in veterinary medicine is further limited by the availability of the commercial devices and a wide range of patient sizes. The goal of this study was to investigate the feasibility, describe the features, and test the accuracy of 3D printed patient-specific skull contoured brain biopsy guides (3D-SCG) in canine cadavers, and in dogs with spontaneous brain disease. We hypothesized that 3DSCGs could be designed based on MRI and computed tomography (CT), would be accurate for biopsy needle placement, and that CT-designed 3D-SCGs would be more accurate than MRI-designed 3D-SCGs, as the bone detail provided by CT would facilitate a better fit of the 3D-SCG to the skull

| METHODS

| Surgical procedures

| RESULTS

| DISCUSSION