{"id":"a99f8864-5ff6-4618-8422-caf6a7643d4b","slug":"robot-assisted-frameless-brain-biopsy-with-computed-tomography-to-fluoroscopy-registration-step-by-step-surgical-video","title":"Robot-assisted frameless brain biopsy with computed tomography-to-fluoroscopy registration: Step-by-step surgical video","authors":["Mario Taravilla-Loma","Carlos Pérez-López","Víctor Rodríguez-Domínguez","Catalina Vivancos Sánchez","Diego Arturo Gordon Mejuto","Alberto Isla Guerrero"],"abstract":"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. 0:14 – Neurological examination 0:29 – Neuro-imaging findings 0:47 – Rationale for the procedure, risks and benefits, and alternatives 1:26 – Positioning and equipment 1:46 – Key surgical step 1. Trajectory planning 1:52 – Key surgical step 2. Registration: CT-to-fluoro “Merge Images” 2:08 – Key surgical step 3. Robotic alignment and locked trajectory 2:22 – Key surgical step 4. Punctiform skin opening 2:29 – Key surgical step 5. Micro-burr hole 2:39 – Key surgical step 6. Needle advancement to target 2:50 – Key surgical step 7. Biopsy sampling 2:58 – Key surgical step 8. Skin closure 3:11 – Disease background 3:32 – Clinical and imaging outcome. Institutional Review Board approval is not required. The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given consent for clinical information to be reported in the journal. The patient understands that the patient’s names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. There are no conflicts of interest. The authors confirm that there was no use of artificial intelligence (AI)-assisted technology for assisting in the writing or editing of the manuscript and no images were manipulated using AI. https://doi.org/10.25259/SNI_158_2026 The views and opinions expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the Journal or its management. The information contained in this article should not be considered to be medical advice; patients should consult their own physicians for advice as to their specific medical needs.","thumbnailUrl":"https://sni-digital-videos.s3.amazonaws.com/placeholders/specialty/neuro-oncology.png","publishDate":"2026-05-15T00:00:00.000Z","doi":"10.25259/SNI_158_2026","categories":["Neuro-oncology","Video Abstract"],"fullTextUrl":"https://surgicalneurologyint.com/wp-content/uploads/2026/05/14548/SNI-17-284.pdf"}