Author: Emily Y. Hirata, Xiaoyu Sherry Liu, Evan Porter, Manju Sharma 👨🔬
Affiliation: University of California San Francisco, University of California, San Francisco, University of California 🌍
Purpose:
The Varian Halcyon Linear Accelerator has become increasingly popular in both community hospitals and academic institutions due to its user-friendly design and operational efficiency. This study compares the commissioning and quality assurance (QA) processes of Halcyon at two distinct facilities: a community hospital and an academic institution. The goal is to share experiences and provide insights for physicists to establish effective protocols that ensure the seamless integration of the Halcyon treatment system into clinical practice.
Methods:
Both institutions followed the Halcyon commissioning process. The academic institution utilized a PTW BEAMSCAN 3D, while the community practice used an IC profiler and the Sun Nuclear 1D water scanning system to measure beam flatness, symmetry, percent depth dose (PDD), and output factors. The calibration process included TG-51 dose calibration, Machine Performance Check (MPC) testing, and image quality assessments. Imaging and data analysis were performed using DoseLab in the academic institution, whereas the community hospital used SunCHECK. Additionally, the comprehensiveness of tests, cost associated with equipment purchases, and protocols for Halcyon annual, monthly, and daily quality assurance (QA) were compared.
Results:
Both institutions employed slightly different measurement methods, equipment and software for analysis, but all mechanical checks met or exceeded vendor specifications. The measured radiation beam parameters, including output factors, were compared to Varian’s golden data and found to be well within specified tolerances limits. MPC tests, image quality assessment and safety checks all passed the tests. However, the Halcyon QA protocols in academic center were more comprehensive compared to those at the community hospital.
Conclusion:
The commissioning and integration of the Halcyon Ver3.0 were achieved in both the community hospital and the academic institution. This study highlights the commissioning experience and QA protocol design at two distinct settings, emphasizing the importance of standardized guidelines to assist physicists in similar efforts.