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Session: Therapy General ePoster Viewing [Return to Session]

Treatment Planning of Intra-Cranial Lesions with Zap Surgical & Comparison with CyberKnife

M Zaman1*, T Loysel2, L Goganovic2, J Ducote3, (1) MZ Physics LLC, Riverside, CA, (2) Zap Surgical, San Carlos, CA, (3) Orange County Cyberknife & Rad Onc Center, Fountian Valley, CA


PO-GePV-T-406 (Sunday, 7/25/2021)   [Eastern Time (GMT-4)]

Purpose: Stereotactic Radiosurgery (SRS) has been utilized as a minimally invasive option to treat intracranial lesions. Zap Surgical, a Gyroscopic radiosurgery system with frameless and image-guided patient positioning and tracking, and sharp dose fall off, is capable to treat various sizes of intracranial lesions. We present treatment planning studies for intracranial lesions of varying sizes and locations. The planning studies will encompass both Forward and Inverse planning aspects of the Zap TPS. These plans will be compared with other frameless SRS system CyberKnife.

Methods: CT studies of 1.25 mm axial slices were registered with post-contrast T1-wighted MRI of 2 mm axial slices. Additionally, T2-weighted Fiesta series were registered for Trigeminal Neuralgia. The prescription doses for the targets and OAR dose constraints followed standard clinical practice and guidance from published literature. Targets were varying in sizes, complexities and proximities to OARs. Planning studies incorporated single and multiple lesions. Planning studies compared both forward and inverse planning results of Zap TPS. These studies were repeated in Accuray Precision TPS. Zap planning results were compared with Accuray planning in terms of target coverage, conformality, beam on time and OAR dose constraints.

Results: All plans in Zap forward and inverse planning and CyberKnife Precision achieved the panning goals of 95% target coverages and met all published OAR dose constraints. Zap inverse forward planning yields shorter beam on time, but with a little less conformality as compared to the inverse plans. Zap treatment plans, both forward and inverse plans, were comparable with CyberKnife plans.

Conclusion: Zap Surgical’s treatment planning system is capable of producing highly conformal treatment plans with sharp dose fall off for intracranial lesions. Both forward and inverse planning aspects result in clinically equivalent plans, with a little better conformality and OAR sparing with inverse planning. The plans are comparable with CyberKnife plans.

Funding Support, Disclosures, and Conflict of Interest: Presenting author received funding for research from Zap Surgical, San Carlos, CA


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