Room: Davidson Ballroom B
Purpose: This study uses Cherenkov light imaging techniques to remotely image radiation beams on a solid slab phantom. From the acquired Cherenkov images, physicists can extract useful information about the radiation field, such as the size and shape of the radiation field. The image derived measurements were compared to routine film-based measurements to demonstrate feasibility of using this technique for remote field verification.
Methods: The Cherenkov imaging acquisition system remotely monitors the beam delivery by acquiring the video frames of Cherenkov signals generated from the solid phantom with different sizes of square 6MV photon beams. The solid phantom was placed at a source surface distance of 100cm, and beams in the size range from 5x5cm2 to 20x20cm2 were imaged. Beam sizes were measured from the acquired Cherenkov images and were compared to that of the radiation field, measured independently using GaF films placed on the surface of the phantom. The interpretation and comparison of Cherenkov distribution and radiation field are completed using procedures commonly used for field verification in the Linac quality assurance guidelines.
Results: The beam size measurements derived from Cherenkov images coincided with the radiation field measurements made by GaF film with accuracy in the range of Â±2mm. The deviations in this range are minor and are well within the tolerance limits prescribed by the established QA guidelines.
Conclusion: The results demonstrate the potential feasibility of using remote Cherenkov image acquisition as a tool for remote field verification.
Funding Support, Disclosures, and Conflict of Interest: B. Pogue, W. Ware, and V. Krishnaswamy are involved in commercial development of Cherenkov cameras, DoseOptics, LLC. Financial support by National Institute of Health (NIH) grants R01 EB023909 and R44 CA199681.