Utilization of Gafchromic ebt۳ Films for Postal Dose Audits of ۶ mv X Ray Beam Calibration of Linear Accelerator

Background: Periodic dose quality audits of medical linear accelerators are essential to ensure proper calibration and accurate dose delivery. We aimed to assess the accuracy of ۶ MV x-ray beam calibration through a postal dose audit using Gafchromic EBT۳ films.Methods: The experiment was conducted at RSUD Pasar Minggu Hospital in Jakarta, Indonesia, in October ۲۰۲۳. A reference calibration curve for Gafchromic EBT۳ films was created by irradiating ۳×۳ cm² films at a ۱۰ cm depth in a water phantom with a ۱۰×۱۰ cm² field and ۱۰۰ cm source-to-surface distance, using doses ۰-۳۰۰ cGy with a ۶ MV x-ray beam from a Varian Trilogy medical linear accelerator at RSUD Pasar Minggu hospital in Jakarta, Indonesia. The films were scanned with a Microtek TMA۱۶۰۰-III scanner, and optical density values were plotted against delivered doses. Three unexposed films were sent to the hospital for irradiation to ۲ Gy in October ۲۰۲۳, and the returned films were analyzed by comparing their optical density values to the calibration curve. The measured dose was ۱.۹۲ Gy, a -۴.۲% deviation from the prescribed ۲ Gy dose, within the ±۵% tolerance. A parallel verification using Optically Stimulated Luminescence Dosimeters confirmed the Gafchromic results. This study demonstrates the feasibility of using Gafchromic EBT۳ films for accurate, efficient calibration of linear accelerator x-ray beams in postal audits.Results: The measured dose was ۱.۹۲ Gy, representing a -۴.۲% deviation from the prescribed ۲ Gy dose, within the accepted ±۵% tolerance. A parallel verification using Optically Stimulated Luminescence Dosimeters showed agreement with the Gafchromic results.Conclusion: The study confirms the feasibility of using Gafchromic EBT۳ films for accurate and efficient calibration of linear accelerator x-ray beams in postal audits.Background: Periodic dose quality audits of medical linear accelerators are essential to ensure proper calibration and accurate dose delivery. We aimed to assess the accuracy of ۶ MV x-ray beam calibration through a postal dose audit using Gafchromic EBT۳ films. Methods: The experiment was conducted at RSUD Pasar Minggu Hospital in Jakarta, Indonesia, in October ۲۰۲۳. A reference calibration curve for Gafchromic EBT۳ films was created by irradiating ۳×۳ cm² films at a ۱۰ cm depth in a water phantom with a ۱۰×۱۰ cm² field and ۱۰۰ cm source-to-surface distance, using doses ۰-۳۰۰ cGy with a ۶ MV x-ray beam from a Varian Trilogy medical linear accelerator at RSUD Pasar Minggu hospital in Jakarta, Indonesia. The films were scanned with a Microtek TMA۱۶۰۰-III scanner, and optical density values were plotted against delivered doses. Three unexposed films were sent to the hospital for irradiation to ۲ Gy in October ۲۰۲۳, and the returned films were analyzed by comparing their optical density values to the calibration curve. The measured dose was ۱.۹۲ Gy, a -۴.۲% deviation from the prescribed ۲ Gy dose, within the ±۵% tolerance. A parallel verification using Optically Stimulated Luminescence Dosimeters confirmed the Gafchromic results. This study demonstrates the feasibility of using Gafchromic EBT۳ films for accurate, efficient calibration of linear accelerator x-ray beams in postal audits. Results: The measured dose was ۱.۹۲ Gy, representing a -۴.۲% deviation from the prescribed ۲ Gy dose, within the accepted ±۵% tolerance. A parallel verification using Optically Stimulated Luminescence Dosimeters showed agreement with the Gafchromic results. Conclusion: The study confirms the feasibility of using Gafchromic EBT۳ films for accurate and efficient calibration of linear accelerator x-ray beams in postal audits.

کلیدواژه ها:

Gafchromic EBT۳ film ، linear accelerator ، dose quality audit ، dose calibration curve