Author: Saad Bin Saeed Ahmed, Marcos Feijoo, Wazir Muhammad, Charles Shang, Naseem Ud Din 👨🔬
Affiliation: South Florida Proton Therapy Institute, Miami Cancer Institute, Blue Physics LLC, Florida Atlantic University 🌍
Purpose: Accurate, efficient, and reliable commissioning of linear accelerator (LINAC) is critical for ensuring high-quality radiation therapy treatments. The study uses advanced detector technology and software tools to address the limitations of conventional water tank scanning methodologies, particularly in small-field dosimetry.
Methods: The system utilizes a plastic scintillator detector (Blue Physics Model 10) with ultra-high temporal resolution, enabling sampling every 300 microseconds for high measurement fidelity. In-house software controls the water tank and optimizes movements to achieve scan speeds up to 30 mm/s without compromising data quality. Preliminary testing was conducted using a Varian Edge LINAC and a PTW water tank. The system's performance was evaluated for small-field dosimetry, precise centering, and field size measurements. Time logs were also evaluated to check its ability to complete full LINAC commissioning, including all photon and electron energies, in one day.
Results: We recorded 4000 samples per mm in profile measurement for 1cm x 1cm 6FFF field under 40 seconds. The percentage depth dose measurements for 2cm x 2cm, 10FFF field was completed in 25 seconds. The results showed unmatched accuracy in small-field measurements and verified the system's capability to complete LINAC commissioning in a single day. We recorded scan times up to 10 times faster than conventional methods like micro diamond chamber. Additionally, annual quality assurance (QA) procedures, which traditionally require extensive time and resources, were completed in as little as one hour using the system.
Conclusion: By integrating advanced detector technology, high-speed scanning, and real-time data analysis, this system redefines the standard for LINAC commissioning and QA.