ABSTRACT
The Zap-X (ZAP Surgical Systems, Inc., San Carlos, CA) is a novel, self-contained, and first-of-its-kind self-shielded robotic therapeutic radiation device dedicated to brain and head and neck stereotactic radiosurgery (SRS). By utilizing an S-band linear accelerator (linac) with a 3.0 megavolt (MV) accelerating potential and incorporating radiation-shielded mechanical structures, the Zap-X does not typically require a radiation bunker, thereby saving SRS facilities considerable time and cost. At the same time, the self-shielded features of the Zap-X are designed for more consistency of radiation protection, reducing the risk to radiation workers and others potentially exposed from a poorly designed or constructed radiotherapy vault. The Zap-X is intended for stereotactic radiosurgical treatment of benign and malignant intracranial and cervical spine lesions. Akin to a large gyroscope, the linac is mounted within a combination of yoked gimbals with attached radiation shielding, each of which accurately rotates around a common isocenter. This mechanical construct enables the linac beam to crossfire from nearly isotropically distributed directions across the superior hemisphere of the patient’s head to provide a spherical dose distribution with steep dose gradients.
This chapter will focus on a description and analysis of the Zap-X from a Physics and application perspective.
