Evaluation of a novel abdominal compression airbag for respiratory motion management and setup reproducibility in upper abdominal radiotherapy.

Abstract

PurposeThis study aimed to evaluate the clinical feasibility and efficacy of a novel abdominal compression airbag (ACA) for respiratory motion management and setup reproducibility in upper abdominal radiotherapy and to compare its performance against free breathing (FB) and the standard abdominal compression plate (ACP).MethodsA total of 54 patients with upper abdominal malignancies were retrospectively analyzed in three groups based on the FB, ACP, and ACA motion management strategies. Respiratory motion amplitude was quantified by calculating the displacement of the liver centroid between the 0% and 50% phases of four-dimensional CT scans. Interfractional setup reproducibility was assessed by analyzing setup errors derived from pretreatment cone-beam CT (CBCT) scans. Statistical comparisons for the respiratory motion amplitude were performed using the Kruskal-Wallis test followed by Dunn's post-hoc test. The analysis of setup stability utilized a linear mixed-effects model.ResultsBoth ACP and ACA significantly attenuated respiratory motion compared to FB (p ConclusionThe ACA achieved a motion restriction performance comparable to the standard ACP, but it was associated with increased uncertainty in the left-right direction. The ACA could serve as a practical alternative with potential workflow and compatibility advantages, preferably coupled with robust image-guided verification to maintain setup stability.