The Automated Quality Assurance (AQA) test is an essential part of CyberKnife machine QA, designed to evaluate the targeting reproducibility of both vertical and horizontal beams. Because the test verifies the ability of the system to repeatedly deliver radiation to the intended target location, accuracy throughout the entire measurement process is critical.
In a traditional film-based workflow, the daily process begins by carefully positioning film inside the AQA phantom. The phantom must then be aligned using the CyberKnife imaging system before irradiation can be performed. After exposure, the films are removed from the phantom and handled with care to avoid confusing the horizontal and vertical measurement planes. The films are subsequently scanned, imported into the analysis software, and evaluated. Only after all these steps have been completed are the results available for review.
While this approach has been used successfully for many years, it comes with several practical challenges. Film handling requires attention to detail and introduces opportunities for user error. The scanning process adds additional time and depends on consistent scanner performance and image quality. Furthermore, results are not immediately available, meaning that users must wait until the films have been processed and analyzed before determining whether the system is performing as expected. As a result, the overall workflow can be time-consuming and resource-intensive, particularly when AQA measurements are performed routinely.
A film-like detector offers a much simpler and more efficient approach. Instead of relying on film, the system utilizes a high-resolution 2D detector array positioned at a 45-degree angle. The measured beam positions are automatically compared against a baseline measurement, providing a direct assessment of targeting reproducibility and positioning accuracy. The workflow is reduced to an easy setup, eliminating the need for film preparation, film handling, scanning, and image import. Results are available immediately after the measurement, allowing users to evaluate system performance without delay.
myQA SRS is an example of such a film-like detector, due to its submillimeter resolution and automated analysis it can be used to replace the traditional film based process and significantly streamline daily AQA testing. The simplified setup, objective evaluation, and instant availability of results reduce workload while maintaining confidence in the assessment of CyberKnife targeting performance. This enables clinics to perform AQA testing more efficiently and consistently, turning a traditionally labor-intensive procedure into a fast and practical QA task.
To learn more, join Nicolas Perichon, Ph.D., Swiss-certified Medical Physicist, as he presents the clinical implementation of the myQA SRS suite for comprehensive patient-specific and machine quality assurance on CyberKnife systems: Webinar myQA SRS for CyberKnife: Patient and Machine QA Experience