Frameless Stereotactic Biopsy of Brainstem Tumors Using the Stealth Autoguide: A Technical Note.

Background and objectives: In the molecular era of neuro-oncology, it is increasingly necessary to obtain tissue for next-generation sequencing and methylome profile for prognosis and targeted oncological management. Brainstem tumors can be technically challenging to biopsy in the pediatric population. Frame-based and frameless techniques have previously been described and proven to be safe and efficacious in children. Recent cranial robotic guidance platforms have augmented the fluency of frameless stereotactic approaches, but the technical nuances of these procedures in children are not often discussed. We present a technical workflow for frameless stereotactic biopsy of brainstem tumors in children using the Medtronic Stealth Autoguide cranial robotic guidance platform and examine safety and efficacy of this surgical approach.

Methods: A minimally invasive, frameless, transcerebellar approach is described, including operative steps and workflow. We assessed operative times, diagnostic accuracy and yield, and complication rates.

Results: Five patients underwent biopsy with the technique described. The youngest patient in our series was of 2 years. The intended target was achieved on postoperative imaging in all cases, and diagnostic tissue was obtained in all 5 patients. One patient had a clinically insignificant hemorrhage.

Conclusion: Frameless stereotactic biopsy of the brainstem can be performed safely, efficiently, and accurately using the Medtronic Stealth Autoguide robotic platform in children as young as 2 years.