Log file‐based quality assurance method for respiratory gating system

Log file analysis revealed precise temporal synchronization, with mean time differences of 0.03 s ± 0.05 s between the planned 25% phase and beam-on, and -0.04 s ± 0.05 s between 75% phase and beam-off. The log-derived beam-on duration (2.61 s ± 0.02 s) closely matched the planned duration (2.66 s ± 0.00 s). Three-month log data showed consistent temporal accuracy, with trigger-on times remaining stable at 2.60 s ± 0.01 s across all measurements. Supporting ion chamber measurements confirmed dosimetric agreement between gating and non-gating modes (difference: 0.05 cGy ± 0.09 cGy) CONCLUSIONS: The proposed log file-based QA method demonstrated high accuracy and reproducibility in assessing respiratory gating performance. This approach provides an efficient, objective method for standardizing QA procedures in respiratory-gated radiation therapy, enhancing treatment accuracy and patient safety.