Dynamic gating window for compensation of baseline shift in respiratory‐gated radiation therapy

摘要: Purpose: To analyze and evaluate the necessity use of dynamic gating techniques for compensation baseline shift during respiratory-gated radiation therapy lungtumors. Methods: Motion tracking data from 30 lungtumors over 592 treatment fractions were analyzed shift. The finite state model (FSM) was used to identify end-of-exhale (EOE) breathing phase throughout each fraction. Using duty cycle as an evaluation metric, several methods compared: Ana posteriori ideal window, a predictive trend-line-based weighted point-based window. These evaluated window types: Superior/inferior (SI) gating, anterior/posterior beam, lateral 3D gating. Results: In absence techniques, SI gave 39.6% cycle. yielded 41.5% weight-based method 36.2%. 34.0%. Conclusions: Dynamic not broadly beneficial due breakdown FSM’s ability EOE phase. When well defined, showed improvement static-window