PURPOSE: To determine whether individual @entity96 @entity1 can be safely treated with pencil beam scanning proton therapy. This study reports a planning preparation workflow that can be used for beam angle selection and the evaluation of the efficacy of abdominal compression (AC) to mitigate motion. METHODS: Four-dimensional computed tomography scans (4DCT) with and without AC were available from 10 @entity96 @entity1 with fluoroscopy-proven motion reduction by AC, previously treated using photons. For each scan, the motion amplitudes and the motion-induced variation of water-equivalent thickness (  WET) in each voxel of the target volume were evaluated during treatment plan preparation. Optimal proton beam angles were selected after volume analysis of the respective beam-specific planning target volume (BSPTV). M   80 and   WET80 derived from the 80th percentiles of perpendicular motion amplitude (M    ) and   WET were compared with and without AC. Proton plans were created on the average CT to achieve target coverage similar to that of the conventional photon treatments. 4D dynamic dose calculation was performed postplan by synchronizing proton beam delivery timing patterns to the 4DCT phases to assess interplay and fractionation effects, and to determine motion criteria for subsequent @entity1 treatment. RESULTS: Selected coplanar beam angles ranged between 180   and 39  , primarily from right lateral (oblique) and posterior (oblique) directions. While AC produced a significant reduction in mean Liver-GTV dose, any reduction in mean heart dose was @entity1 dependent and not significant. Similarly, AC resulted in reductions in M    ,   WET, and BSPTV volumes and improved dose degradation (  @entity12840 ) within the CTV. For small motion (M   80 < 7 mm and   WET80 < 5 mm), motion mitigation was not needed. For moderate motion (M   80 7-10 mm or   WET80 5-7 mm), AC produced a modest improvement. For large motion (M   80 > 10 mm or   WET80 > 7 mm), AC and/or some other form of mitigation strategies were required. CONCLUSION: A workflow for screening @entity1 ' motion characteristics and optimizing beam angle selection was established for the pencil beam scanning proton therapy treatment of @entity96 . Abdominal compression was found to be useful at mitigation of moderate and large motion.

Evaluation of motion mitigation using abdominal compression in the clinical implementation of pencil beam scanning proton therapy of XXXX .

@entity1 :: ('9606', 'Species') :: ['patients', 'patient'] @entity12840 :: ('25802', 'Gene') :: ['D95 and   D1'] @entity96 :: ('MESH:D008113', 'Disease') :: ['liver tumors', 'liver tumor']
@entity96 :: (MESH:D008113,Disease) :: ['liver tumors']
