ESTRO 2024 - Abstract Book

S1678

Clinical - Lung

ESTRO 2024

performed using a pruning-local algorithm, and the results were compared with manually selected angle plans. The adaptability of the angle optimization algorithm to different optimization strategies was investigated, with five specific optimization strategies defined (standard plan, increased prescription dose, reduced lung dose, reduced heart dose, and reduced spinal cord dose). Angle optimization plans and corresponding manually selected angle plans were generated for each strategy, and the evaluation was based on dose-volume parameters, including PTV Dmax, PTV Dmin, among others.

Results:

For the standard strategy plans, there were no statistically significant differences (p > 0.05) in PTV Dmax, PTV Dmin, spinal cord Dmax, heart Dmean, homogeneity index (HI), and conformity index (CI) among the three sets of angles. However, in angle optimized plans, LUNG-PTV's V20, V5, and Dmean (28.73±8.61%, 54.65±18.41%, and 908.55±318.43 cGy) were higher than in manually planned ones (25.94±11.46%, 53.16±16.41%, and 858.65±352.14 cGy, p < 0.05). In the increased prescription dose strategy plans, the results were similar to the standard strategy