The Zap-X Radiosurgical System in the Treatmentof Intracranial Tumors

BACKGROUND AND IMPORTANCE:The Zap-X system (Zap Surgical Systems Inc, SanCarlos, California) is a radically new surgical robot designed for brain and head and neckradiosurgery. It represents the first new dedicated brain stereotactic radiosurgery platformin almost half a century optimizing the goals of safety, speed, and accuracy. The Zap-Xsystem was used in a required Chinese National Medical Products Administration clinicalstudy. In early January 2020, 2 patients were treated with the Zap-X robot prior to a nationalCOVID-19 lockdown. Both were closely followed via clinical exam and magnetic resonanceimaging (MRI) imaging. Prospectively collected data were used to generate this report.

CLINICAL  PRESENTATION:Two  female  patients,  each  harboring  either  a  trigeminalschwannoma or petroclival meningioma, were treated with the Zap-X robot. Respectivetumor volumes were 2.60 and 4.02 cm3. A radiation dose of 13 Gy was prescribed to the50% isodose line. At 8 mo of follow-up, preoperative symptoms were either resolved orstable and MRI imaging demonstrated a 31% and 56% reduction in lesion volume, respec-tively. In both patients, symptoms improved, and tumor volumes decreased, whereas nomajor complication was observed.

CONCLUSION:Given  only  2  patients  and  short-term  follow-up,  any  conclusions  aboutthe safety and efficacy of the Zap-X radiosurgery robot are preliminary. However, in theabsence of any other published outcomes to date, this small case series may be of interestto many radiosurgical specialists.