Background: Histomolecular tissue diagnosis is critical for treatment selection in deep-seated or multifocal intracranial lesions. Robot-assisted stereotaxy can improve workflow reproducibility and diagnostic accuracy by combining preplanned trajectories with rigid, coaxial alignment. Case Description: A 46-year-old woman presented with 15 days of left leg weakness and left arm paresthesia. Contrast-enhanced magnetic resonance imaging (MRI) revealed multiple enhancing lesions, with a dominant parasagittal frontoparietal cortico-subcortical mass (~3.5 cm). A frameless robot-assisted stereotactic biopsy was performed using preoperative computed tomography (CT) and MRI fusion to define entry/target points and avoid vascular/eloquent structures. Intraoperatively, true orthogonal anteroposterior and lateral fluoroscopic images were acquired and registered to the preoperative CT-MRI dataset (ExcelsiusGPS “Merge Images”) to enable CT-to-fluoroscopy guidance. The robotic arm aligned and locked the working channel coaxially with the planned trajectory. Subsequently, a punctiform skin opening and a 2.7-mm micro-burr hole were created, the biopsy needle was advanced with controlled movements, and multiple core specimens were obtained. Postoperatively, the patient remained neurologically stable. CT showed expected tract changes without clinically significant hemorrhage. Histopathology and molecular profiling were consistent with glioblastoma, isocitrate dehydrogenase-wildtype, central nervous system World Health Organization grade 4. Conclusion: This technical video demonstrates a step-by-step frameless robot-assisted brain biopsy workflow using CT-MRI planning and CT-to-fluoroscopy registration, highlighting practical pearls for reproducible minimally invasive trajectory execution. As a single-case technical report, it illustrates workflow implementation without supporting comparative conclusions regarding safety, accuracy, efficiency, or superiority over other stereotactic methods.
Taravilla-Loma et al. (2026) studied this question.