Non-invasive CT-based simulation of third ventricle puncture: Identifying optimal surface landmark-guided trajectories using 3D Slicer.

BACKGROUND: The third ventricle is surrounded by critical deep brain nuclei, making direct cannulation a high-risk procedure with a substantial likelihood of complications. These risks have limited systematic clinical investigation of third-ventricle puncture techniques. CT-based virtual simulation offers a promising non-invasive alternative. Although prior studies have explored CT-based simulation for lateral ventricular access, most rely on proprietary navigation software, limiting their broader applicability. In this study, we propose a non-invasive simulation framework for third-ventricle puncture based on CT imaging and the open-source platform 3D Slicer. METHODS: CT datasets from 155 adult patients were processed using 3D Slicer to reconstruct patient-specific cranial anatomy and generate virtual puncture trajectories. Eight frontal entry points were evaluated in combination with three sagittal targeting strategies based on surface anatomical landmarks: nasion-lambda (NL), medial canthi midpoint-lambda (ML), and rinion-lambda (RL). The probability of each trajectory successfully reaching the third ventricle was analyzed. RESULTS: The reconstructed trajectories demonstrated that when the entry point was located 1.5 cm anterior to the coronal suture and 2.5 cm lateral to the midline, the probability of successful third-ventricle access was highest for the RL trajectory (99%), followed by ML (97%) and NL (83%). CONCLUSIONS: CT-based trajectory reconstruction using the open-source 3D Slicer platform provides a feasible, safe, and cost-effective approach for studying third-ventricle puncture. This method is particularly advantageous in resource-limited settings and in research scenarios where recruitment for invasive procedures is challenging.