Whole-Body Dose of Patients Treated With ZAP-X Intracranial Gyroscopic Stereotactic Radiosurgery

During the delivery of radiosurgery treatments, a small dose is given unintentionally to the areas of the patient’s body outside the primary treatment volume. It is a common practice for radiotherapy platform developers to minimize the dose outside the primary radiation field by providing X-ray target shielding in the beam-defining collimator head of such systems. The amount of such doses was measured for the ZAP-X® delivery platform by designing a phantom-based set-up mimicking the patient and measuring the dose with an ionization chamber and OSLDs. Furthermore, during several clinical ZAP-X radiosurgery treatment deliveries, the dose received by patients was measured with film-based dosimeters. The results were determined as absolute values and as a percentage of the primary dose.