Beam data commissioning, validation and clinical implementation of SRS gyroscopic system

Area of Science:

• Medical Physics
• Radiotherapy Technology
• Radiation Oncology

Background:

• The ZAP-X gyroscopic radiosurgery system presents unique challenges for beam data acquisition and validation due to its novel design.
• Existing international guidelines lack specific methodologies and correction factors for this advanced radiosurgery platform.

Purpose of the Study:

• To commission the ZAP-X system's Treatment Planning System (TPS) by acquiring and validating its beam data.
• To establish and implement machine- and patient-specific quality assurance (QA) protocols for the ZAP-X system.

Main Methods:

• Beam data were acquired using microsilicon, microdiamond detectors, ionization chambers, and a plastic scintillation detector.
• Monte Carlo (MC) simulations using SciMoCa™ were employed for comparison and validation.
• Patient-specific QA involved an anthropomorphic phantom, a 2D array, and SciMoCa™ for comprehensive dose assessment.

Main Results:

• Detector agreement for Percentage Depth Dose (PDD) was within 1% beyond the depth of maximum dose (dmax).
• Solid-state detectors showed good congruence with MC data; microsilicon detectors provided sharper penumbra information.
• Output factor measurements demonstrated strong agreement between SciMoCa™ and plastic scintillation detector data (max difference 2.1%).

Conclusions:

• Multiple measurement methods showed strong agreement, validating the commissioning process.
• Monte Carlo simulations are crucial for validating TPS commissioning data for the ZAP-X system.
• The developed methods and materials can assist other facilities implementing this gyroscopic radiosurgery system.